What is the name of the bug that emerging from a wood chip like cocoon?

We found it on the wall of a home at West Palm Beach Florida. Is this a kind of infestation or a sick tree near the house fall on the wall?

That is a bagworm moth, in the family Psychidae.


Groundhogs are also referred to as woodchucks or whistle pigs. They are a member of the squirrel family. There are six species of woodchucks and marmots that occur in the United States. These animals commonly invade cropland and vegetable gardens, eating or destroying vegetables and landscape plants. Although groundhogs are slow runners, they scurry quickly to their dens when they sense danger. The primary predators of groundhogs are hawks, foxes, coyotes, bobcats, dogs and humans. However, motorized vehicles kill many groundhogs each year. Keep reading for more groundhog/ woodchuck facts , and to learn how to get rid of groundhogs .

1. Termite Shelter Tubes

Termite shelter tubes in fan pattern along foundation wall. Note tubes developed along small-diameter copper tubing

These mostly originate from the ground crossing barriers for example metal capping and on walls or foundations.

The tubes are important in protecting the termites from predators, maintains a dark and humid environment for the termite food storage and their development.

The termites are unique creatures and construct the structures at night when they are less likely to desiccate, in most cases the structures are clay like in texture , brown or dark brown in color.

Some are narrow while others are wider, if they are narrow say 10 millimeters they contain soldiers and workers foraging for food. On the other hand, if they are wider say 50 millimeters then they consist of large numbers of workers and soldiers transporting food and this is the stage, which is the most destructive.

Since they come in large numbers, they can cause immense damage on the wood or carvings they locate themselves. It is vital to look for signs of termites such tubes to avoid damages and losses

Codling Moth

Codling moth belongs to the family Tortricidae. This is one of the largest families of moths, with about 950 North American species. It includes a number of important tree fruit pests, e.g., codling moth, oriental fruit moth and several species of leafrollers. These moths are small, usually gray or brown, and their wings have bands or mottled areas. The front wings are usually square tipped. While at rest, these moths hold their wings roof-like over the body.

Codling moth originated in Asia Minor but has been a principal pest of apple and pear in North America for more than 200 years. With the exception of Japan and part of mainland Asia, it is found wherever apples are grown throughout the temperate regions of the world. Codling moth larvae bore deep into the fruit, making it unmarketable. If uncontrolled, codling moth can destroy most of the crop. By the first half of the 20th century, the codling moth was a major pest in all apple growing districts of North America. It was not until synthetic organic insecticides became available in the late 1940s that the codling moth could be maintained at very low levels in commercial orchards.


Codling moth prefers apple but also attacks pear, large-fruited hawthorn and quince. In California, races of codling moth attack prune and walnut. Pears have some natural resistance to attack by codling moth when fruit are small because of their hardness, however, pears can become heavily infested in late summer as they mature. Infestations in stone fruits such as apricot and cherry are extremely rare and usually occur only where heavy infestations of apple or pear are nearby.

Life Stages

The codling moth egg is oval, flat and, when first laid, almost transparent. It is about 1/12-inch (2 mm) long. Eggs are laid individually on leaves or fruit and are very difficult to find, especially in a commercial orchard.


The newly hatched larva is only about 1/10 inch (2 to 3 mm) long. Its head is black, and the body is creamy white. The full grown larva is 1/2 to 3/4 inch (12 to 20 mm) long, has a brown or black head capsule and thoracic shield. The body is usually creamy white but turns slightly pink when mature. Unlike other caterpillar larvae that feed on the flesh of the fruit, such as oriental fruit moth and lesser apple worm, the codling moth larva burrows through the flesh and feeds primarily on seeds. When mature the codling moth larvae exits the fruit and searches for a sheltered location on the tree or at the base of the tree and spins a cocoon.

The codling moth pupa is brown and about 1/2 inch (12 mm) long. It resides inside a cocoon spun by the mature larva on the tree beneath bark scales or in a sheltered place at the base of the tree.


The adult codling moth is about 1/2 inch (12 mm) long. At first glance, it seems a nondescript dull gray, but closer inspection shows the wings are crossed with fine alternating gray and light-colored bands. The wings are tipped by a patch of bronze-colored scales that reflect in sunlight. The moth holds its wings tent-like over its body when at rest.

Life history

The codling moth spends the winter as a mature larva in a cocoon. Larvae are found under loose bark scales on the tree, in litter at the base of the tree, in wood piles, on picking bins in the orchard or on farm buildings near packing sheds where culled apples might have been dumped. Overwintering larvae begin changing into pupae early in the spring prior to the opening of blossoms. The first adult moths begin to emerge around the time of full bloom of Red Delicious. Peak emergence is usually 17 to 21 days later, though this depends on temperature. Adults continue to emerge for 6 or 7 weeks. Moths are most active on warm evenings, but are inactive at temperatures below 60 °F. Moths mate and begin laying eggs within a day of emerging. First generation eggs are laid primarily on leaves, although some may be found on fruit. Eggs require 8 to 14 days to incubate.

Newly hatched larvae find fruit and enter either at the calyx end or through the side. They bore through the skin and feed on the fruit flesh for a few days, then move towards the apple core where they feed on seeds and flesh surrounding the seeds. As they feed, they push excrement out of the apple through an entry hole, which is gradually enlarged and often serves as an exit hole. Larvae are fully grown in three to four weeks, at which time they leave the fruit in search of sheltered places to spin cocoons. In our region, most larvae pupate and, in two to three weeks, emerge as second-generation adults. However, a small percentage of first generation larvae enter diapause, a state of arrested development, and do not emerge as adults until the following spring. Second generation adults usually begin emerging in early July. Adult activity peaks in mid-July to early August and continues into early September. Second generation larvae are in the fruit from mid-July until late September. Mature larvae of the second generation leave fruit as early as mid-August in search of overwintering sites. It has become more common to have a third codling moth generation and, in exceptionally warm years, a partial fourth generation. Moths representing a third flight emerge in late August or early September and deposit eggs. While larvae of the third generation enter fruit, causing severe levels of crop loss in some instances, most do not complete development before winter conditions arrive or fruit is harvested.


Injury is caused when larvae feed on fruit. There are two types of damage: stings and deep entries. Stings are shallow entries where a larva burrows into the flesh and then dies or a larva briefly feeds at a location then abandons that site and moves to another location. On more mature fruit, apple or pear, a reddish colored ring often forms around a new entry or sting. Deep entries occur when a larva bores through the flesh of the fruit, eventually arriving at the center of the apple or pear where it feeds primarily on seeds. Deep entries are often characterized by brown frass, or excrement, extruding from an enlarge entry hole or a new hole destined to as an exit for the mature larva. In pear, deep entries are most often noticed when frass appears at the calyx end of the fruit. Both types of damage make fruit unmarketable, but deep entries are a problem in stored fruit because bacteria and fungi associated with the entries enhances fruit rot.


Pheromone traps can be used to monitor adult activity. Traps should be placed in the orchard by the pink stage of apple flower-bud development. Traps should be examined frequently until first moths are captured and then weekly thereafter. Trap placement and maintenance are critical to obtaining reliable information on which to make management decisions.

Traps should be placed in the top 1/3 rd of the tree within the canopy, making sure the entrance to the trap is not blocked. There are various types of traps but the most common one used over the past decade is the delta-type. This trap provides efficient capture of moths and is made of durable materials that maintains its shape throughout the season. In most traps an insert with a sticky surface is where moths are captured. Some inserts are coated with a sticky adhesive that requires stirring occasionally to maintain its effectiveness in capturing moths. Other inserts have a dry adhesive that does not require stirring. Both types of inserts should be changed if they become contaminated with dust or other debris.

There are several different lures that can be used to monitor codling moth adult activity. Most apple orchards in Washington are treated with pheromone mating disruption products and in these orchards a “high-load” pheromone lure, or a lure containing pheromone plus a non-pheromone component, such as pear ester, should be used. The lure used in a trap should be changed on the interval recommended by the company providing the product.

To assess codling moth damage, examine fruit at the end of the first generation, in early July, and again before harvest. A visual inspection of fruit viewing half of 30 to 40 fruit from least 40 trees, or in high-density orchards at 40 locations, for every 10 acres. Most fruit damage typically occurs in the upper half of trees, so sampling this region is critical.

Some growers, especially organic growers, have banded trees with cardboard strips as a means of monitoring presence and density of codling moth and as part of a control program. Mature larvae migrating down the tree in search of shelters to spin cocoons enter these bands. Bands can be removed and examined after the first generation or after harvest. If the intent is to estimate the codling moth population, banding 40 trees per 10-acre block is recommended. This technique is much more efficient on young trees with smooth bark. On older trees, the bark should be scraped smooth and the bands attached at the scraped area to enhance capture of larvae.

Treatment thresholds

Estimating the population level of codling moth in commercial orchards is challenging. Visual observation of fruit injury can provide valuable information about the level and distribution of codling moth in an orchard. See the discussion above for information on this method. If fruit injury monitoring reveals injury levels of 0.5% or more then increased controls should be implemented.

Capture of codling moth adults in pheromone traps can be used to estimate population levels and help make control decisions. The number of traps used, their location, trap maintenance and the quality of the pheromone trap are all critical elements to the successful use in a threshold-based decision program.

To implement a threshold-based decision program it is essential to use one monitoring trap for every 2.5 acres. Traps should be placed in the orchard before the accumulation of 175 degree-days (or at the pink stage of apple bud development). Trap placement within the orchard and tree will influence moth captures. Avoid placing traps at the very edge of a block. It is best to place a trap in the center of each 2.5 acre section to be monitored, however, traps may be placed toward an outside border that is impacted by known history of pest high pressure. See the discussion above regarding the kind of traps and lures to be used in monitoring codling moth adults.

Traps should be checked once a week after the first moths are caught. After a total of 30 moths have been captured, or if the trapping surface becomes dirty, the trap bottom or insert should be replaced. Count the number of moths in each trap and remove moths. Record the catch separately for each trap. The idea behind using trap catch as a treatment threshold is that sprays are applied only when moth catch exceeds certain number, the capture threshold. Two threshold methods can be used with moth capture data.

With the first method, the trap catch threshold is 2 moths captured on two consecutive weeks. Thus, if a trap catches 2 moths one week and 2 or more the next, a treatment should be applied to the area associated with the trap (2.5 acres). However, if a trap catches 2 moths, then 1 moth, then 2 moths, a spray is not recommended. This method has worked well for growers in British Columbia and Washington.

With the second method, the codling moth degree-day model is incorporated with moth capture in pheromone traps. The same density of traps is used, one trap every 2.5 acres. Moth capture in a trap is accumulated between 175 to 425 degree-days. The recommended treatment threshold is a total 5 moths, so if 6 or more moths have been captured, then the area associated with the trap should be treated at the 425 degree-day timing. If a treatment is justified based on accumulated moth captures, then moth capture accumulation is started over for the next time period, based either on the expected residue of the pesticide or over the next 250 degree-days. Where codling moth populations are low, it may be possible to delay the treatment decision until 525 degree-days. If by 525 degree-days the moth capture threshold has not been exceeded, then a control treatment should not be applied. If the threshold is exceeded, apply a control treatment as soon as possible. Then moth capture accumulation is started over for the next time period, based either on the expected residue of the pesticide or over the next 250 degree-days.

For the second generation and beyond, the moth capture treatment threshold is reduced to an accumulation of 3 moths, because capture efficiency of pheromone traps is reduced in this time period. Start accumulating moth catch at 1175 degree-days. If 4 or more moths are captured over the next 250 degree-days, a control treatment should be applied to the area associated with the trap. If moth captures do not exceed 3 moths, a control treatment should not be necessary, and the accumulation of moth catch from zero again.

Caution: Control treatments should be applied to the part of the orchard represented by moth capture in the trap that has exceeded the treatment threshold. However, depending on how the orchard is designed, an area larger than that represented by an individual trap may need to be treated. The use of treatment thresholds based on codling moth capture in pheromone traps usually reduces use of insecticides. The treatment thresholds recommended above should only be applied to the individual trap associated with 2.5 acres and should not be used as a threshold based on an average moth capture over the entire orchard. If trap densities are less than on every 2.5 acres, for example one trap per 5 or 10 acres, then the thresholds described above are not applicable and if used could result in unacceptable crop loss.

Biological control

The codling moth has several natural enemies, however, it is impractical to rely solely upon them to suppress codling moth populations to levels that would result in acceptable crop protection. Most conventional insecticides are toxic to the natural enemies of codling moth. Where mating disruption or soft insecticides are implemented, natural enemies, especially parasites, can be an important component of the pest management program.

Trichogramma sp. are parasites that attack codling moth eggs. These small wasps can parasitize a high percentage of eggs under favorable conditions. Another parasite, Ascogaster quadridentata, was introduced to the United States from France as a biological control for codling moth. This wasp deposits an egg in the codling moth egg, but it does not kill the codling moth until the larva is nearly full grown.

Degree-day model

Insects are cold-blooded animals and thus how fast they develop from egg to adult is driven by the temperatures they are exposed to. Degree-day models, that accurately predict the development of insects, have been used for several insects, including the codling moth. Since the early 1980s the codling moth degree-day model has been used to more precisely time insecticide applications.

In the past, a biological event, the first capture of codling moth adults in a pheromone trap, has been used to initiate the accumulation of degree-days. This biological event was referred to as the “biofix,” because it represented a biological fix point to initiated the codling moth model. Establishing a biofix for codling moth was a challenge in many orchards, therefore, WSU scientists developed a no-biofix model that accurately predicts the development of codling moth by accumulating degree-days from January 1 of each year. On average, the first emergence of codling moth adults starts at 175 (°F) degree days from January 1, so there is no need to use moth capture in pheromone traps to initiate the accumulation of degree-days. In the past, the degree-day total was set to 0 when the biofix, first moth capture, was determined. However, with the no-biofix model degree-days there is no reset of degree-days to zero.

Timing of pesticide treatments depends on the life stage targeted.

225 degree timing:The first target is the codling moth eggs. Eggs begin to be deposited between 225-275 degree-days. It is possible to apply insecticides, referred to as residual ovicides, between the 225-275 degree-day period. These insecticides kill codling moth eggs that were deposited on top of residues. Some insecticides applied at this time will also kill leafroller larvae that are present in the orchard.

Delayed first cover timing: It is also possible to apply horticultural oil at 375 degree-days, a treatment that kills codling moth eggs already deposited. Horticultural mineral oil is referred to as a topical ovicide. If a residual ovicide or oil is applied as outlined above, then the next time to apply an insecticide would be at 525 degree-days. This timing if often referred to as a delayed first cover spray, which targets codling moth larvae hatching from eggs.

If no residual or topical ovicides are applied in the 225-275 or 375 degree-day timings, respectively, then insecticides should be applied at 425 degree-days, which targets the beginning of codling moth egg hatch period.

Repeat applications of insecticides in the first codling moth generation should be based on the need to suppress the pest population. The interval between successive insecticide treatments should be determined by the length of the active residue of the insecticide used. Timing for the second codling moth generation should also be based on degree-day accumulations. Moths of the second generation will being emerging at 1175 degree-days and first egg hatch will begin at 1400 degree-days. Control timing strategies used in the first generation can be applied in the second generation. The best way to utilize the codling moth model is to access the WSU Decision Aid System ( This computer based system automatically updates the codling moth model but it also provides management guidelines and is linked to the pesticide recommendations found in the WSU Crop Protection Guide for Tree Fruit – EB0419.

Mating disruption

Mating disruption is a standard control for codling moth applied to roughly 90% of apple acres in Washington. Pheromones applied in orchards work to disrupt or delay the ability of male codling moth to locate and mate with females, resulting in a reduction of viable offspring. The term ‘mating disruption’ is often associated with this control technique. Pheromone mating disruption has been shown to significantly reduce the amount of insecticides required to control codling moth in apple orchards.

There are several different kinds of dispensers utilized to deliver codling moth pheromone in orchards. For many years the hand-applied dispensers were the most common pheromone delivery system. However, aerosol emitter technologies has become more common as a method of delivering codling moth pheromone in orchards. Pheromone dispensers should be placed in the orchard prior to the first moth flight in spring. The number of dispensers applied per area depends on the type of product used. Placement of dispensers should be in the upper third of the tree canopy.

Organic control programs

Control of codling moth in organic orchards is impossible without the use of pheromones (mating disruption). However, pheromones alone are often insufficient to provide adequate crop protection, thus supplemental pesticides applications are usually needed. The number and kinds of organic pesticides for codling moth control are very limited. The codling moth virus and horticultural oil are effective organic insecticide, but they have to be applied frequently. These two insecticides are best used together as a tank mix application. The insecticide Entrust (spinosad) is also an effective organic insecticide, but the number of applications per season is restricted by the label. Other botanical and biological insecticides have not been effective at controlling codling moth in organic orchards.


The name "monarch" is believed to have been given in honor of King William III of England, as the butterfly's main color is that of the king's secondary title Prince of Orange. [11] The monarch was originally described by Carl Linnaeus in his Systema Naturae of 1758 and placed in the genus Papilio. [12] In 1780, Jan Krzysztof Kluk used the monarch as the type species for a new genus, Danaus.

Danaus (Ancient Greek Δαναός ), a great-grandson of Zeus, was a mythical king in Egypt or Libya, who founded Argos Plexippus ( Πλήξιππος ) was one of the 50 sons of Aegyptus, the twin brother of Danaus. In Homeric Greek, his name means "one who urges on horses", i.e., "rider" or "charioteer". [13] In the 10th edition of Systema Naturae, at the bottom of page 467, [14] Linnaeus wrote that the names of the Danai festivi, the division of the genus to which Papilio plexippus belonged, were derived from the sons of Aegyptus. Linnaeus divided his large genus Papilio, containing all known butterfly species, into what we would now call subgenera. The Danai festivi formed one of the "subgenera", containing colorful species, as opposed to the Danai candidi, containing species with bright white wings. Linnaeus wrote: "Danaorum Candidorum nomina a filiabus Danai Aegypti, Festivorum a filiis mutuatus sunt." (English: "The names of the Danai candidi have been derived from the daughters of Danaus, those of the Danai festivi from the sons of Aegyptus.")

Robert Michael Pyle suggested Danaus is a masculinized version of Danaë (Greek Δανάη ), Danaus's great-great-granddaughter, to whom Zeus came as a shower of gold, which seemed to him a more appropriate source for the name of this butterfly. [15]

There are three species of monarch butterflies:

  • D. plexippus, described by Linnaeus in 1758, is the species known most commonly as the monarch butterfly of North America. Its range actually extends worldwide and can be found in Hawaii, Australia, New Zealand, Spain and the Pacific Islands.
  • D. erippus, the southern monarch, was described by Pieter Cramer in 1775. This species is found in tropical and subtropical latitudes of South America, mainly in Brazil, Uruguay, Paraguay, Argentina, Bolivia, Chile and southern Peru. The South American monarch and the North American monarch may have been one species at one time. Some researchers believe the southern monarch separated from the monarch's population some 2 mya, at the end of the Pliocene. Sea levels were higher, and the entire Amazonas lowland was a vast expanse of brackish swamp that offered limited butterfly habitat. [16]
  • D. cleophile, the Jamaican monarch, described by Jean-Baptiste Godart in 1819, ranges from Jamaica to Hispaniola. [17]

Six subspecies and two color morphs of D. plexippus have been identified: [5]

  • D. p. plexippus – nominate subspecies, described by Linnaeus in 1758, is the migratory subspecies known from most of North America.
    • D. p. p. form nivosus, the white monarch commonly found on Oahu, Hawaii, and rarely in other locations. [18]
    • D. p. p. (as yet unnamed) – a color morph lacking some wing vein markings. [19]

    The percentage of the white morph in Oahu is nearing 10%. On other Hawaiian islands, the white morph occurs at a relatively low frequency. White monarchs (nivosus) have been found throughout the world, including Australia, New Zealand, Indonesia, and the United States. [18]

    Some taxonomists disagree on these classifications. [16] [20]

    Monarchs belong in the subfamily Danainae of the family Nymphalidae Danainae was formerly considered a separately family Danaidae. [21]

    A 2015 paper identified genes from wasp bracoviruses in the genome of the North American monarch [22] leading to articles about monarch butterflies being genetically modified organisms. [23] [24]

    The monarch's wingspan ranges from 8.9 to 10.2 centimetres (3.5–4.0 in). [7] The upper sides of the wings are tawny orange, the veins and margins are black, and there are two series of small white spots in the margins. Monarch forewings also have a few orange spots near their tips. Wing undersides are similar, but the tips of forewings and hindwings are yellow brown instead of tawny orange and the white spots are larger. [25] The shape and color of the wings change at the beginning of the migration and appear redder and more elongated than later migrants. [26] Wings size and shape differ between migratory and non-migratory monarchs. Monarchs from eastern North America have larger and more angular forewings than those in the western population. [10] Monarchs are commonly and easily mistaken for the similar viceroy butterfly – the two species are Müllerian mimics.

    Monarch flight has been described as "slow and sailing", [27] with a flight speed estimated at approximately 9 km/h or 5.5 mph. [28] For comparison, the average human jogs at a rate of 9.7–12.9 km/h (6–8 mph).

    Adults are sexually dimorphic. Males are slightly larger than females [10] [25] and have a black patch or spot of androconial scales on each hindwing (in some butterflies, these patches disperse pheromones, but are not known to do so in monarchs). The male's black wing veins are lighter and narrower than those of females. [29]

    One variation, the "white monarch", observed in Australia, New Zealand, Indonesia and the United States, is called "nivosus" by lepidopterists. It is grayish white in all areas of its wings that are normally orange and is only about 1% or less of all monarchs, but populations as high as 10% exist on Oahu in Hawaii. [18]

    The monarch has six legs like most adult insects, but uses only its middle legs and hindlegs in walking as its forelegs are small, as in all Nymphalidae, and held against its body. [30]

    Detailed measurements Edit

    A study in 2015 examined a preserved collection of male and female monarch specimens from eastern North America to evaluate the sex-based differences in fine-scale wing and body structure. [31] The study found significant differences in overall wing size and in the physical dimensions of wings. Males tended to have larger wings than females, and were heavier than females, on average. Both males and females had similar thorax dimensions (wing muscles are contained in the thorax). Female monarchs tended to have thicker wings, which is thought to convey greater tensile strength. This would make female wings less likely to be damaged during migration. Also, females had lower wing loading than males (wing loading is a value derived from the ratio of wing size to body mass), which would mean females require less energy to fly. [32]

    The range of the western and eastern populations of D. plexippus plexippus expands and contracts depending upon the season. The range differs between breeding areas, migration routes, and winter roosts. [10] : (p18) However, no genetic differences between the western and eastern monarch populations exist [33] reproductive isolation has not led to subspeciation of these populations, as it has elsewhere within the species' range. [10] : (p19)

    In the Americas, the monarch ranges from southern Canada through northern South America. [4] It has also been found in Bermuda, Cook Islands, [34] Hawaii, [35] [36] Cuba, [37] and other Caribbean islands [10] : (p18) the Solomons, New Caledonia, New Zealand, [38] Papua New Guinea, [39] Australia, the Azores, the Canary Islands, Madeira, continental Portugal, Gibraltar, [40] the Philippines, and Morocco. [41] It appears in the UK in some years as an accidental migrant. [42]

    Overwintering populations of D. plexippus plexippus are found in Mexico, California, along the Gulf Coast, year round in Florida, and in Arizona where the habitat has the specific conditions necessary for their survival. [43] [44] On the US East Coast, they have overwintered as far north as Lago Mar, Virginia Beach, Virginia. [45] Their wintering habitat typically provides access to streams, plenty of sunlight (enabling body temperatures that allow flight), and appropriate roosting vegetation, and is relatively free of predators.

    Overwintering, roosting butterflies have been seen on basswoods, elms, sumacs, locusts, oaks, osage-oranges, mulberries, pecans, willows, cottonwoods, and mesquites. [46] While breeding, monarch habitats can be found in agricultural fields, pasture land, prairie remnants, urban and suburban residential areas, gardens, trees, and roadsides – anywhere where there is access to larval host plants. [47]

    Habitat restoration is a primary goal in monarch conservation efforts. Habitat requirements change during migration. During the fall migration, butterflies must have access to nectar-producing plants. During the spring migration, butterflies must have access to larval food plants and nectar plants.

    The monarch butterfly undergoes four stages of complete metamorphosis:

    Eggs Edit

    Larvae Edit

    The caterpillar goes through five major distinct stages of growth, and after each one it molts. Each caterpillar, or instar, is larger than the previous after molting, as it eats and stores energy in the form of fat and nutrients to carry it through the nonfeeding pupal stage. Each instar lasts about 3 to 5 days, depending on various factors such as temperature and food availability. [4]

    The first instar caterpillar that emerges from the egg is pale green and translucent. It lacks banding coloration or tentacles. The larvae or caterpillar eats its egg case and begins to feed on milkweed. It is during this stage of growth that the caterpillar begins to sequester cardenolides. The circular motion a caterpillar uses while eating milkweed prevents the flow of latex that could entrap it. The first instar is usually between 2 and 6 mm long.

    The second instar larva develops a characteristic pattern of white, yellow and black transverse bands. It is no longer translucent but is covered in short setae. Pairs of black tentacles begin to grow, one pair on the thorax and another pair on the abdomen. Like the first instar, second-instar larvae usually eat holes in the middle of the leaf, rather than at the edges. The second instar is usually between 6 mm and 1 cm long.

    The third instar larva has more distinct bands and the two pairs of tentacles become longer. Legs on the thorax differentiate into a smaller pair near the head and larger pairs further back. These third-stage caterpillars begin to eat along the leaf edges. The third instar is usually between 1 and 1.5 cm long.

    The fourth instar has a different banding pattern. It develops white spots on the prolegs near the back of the caterpillar. It is usually between 1.5 and 2.5 cm long.

    The fifth instar has a more complex banding pattern and white dots on the prolegs, with front legs that are small and very close to the head. A caterpillar at this stage has an enormous appetite, being able to consume a large milkweed leaf in a day. Its length ranges from 2.5 to 4.5 cm. [4]

    As the caterpillar completes its growth, it is 4.5 cm long (large specimens can reach 5 cm) and 7 to 8 mm wide, and weighs about 1.5 grams, compared to the first instar, which was 2 to 6 mm long and 0.5 to 1.5 mm wide. Fifth-instar larvae increase in weight 2000 times from first instars. Fifth-stage instar larva can chew through the petiole or midrib of milkweed leaves and stop the flow of latex. After this, they eat more leaf tissue. Before pupation, larvae must consume milkweed to increase their mass, after which they stop feeding and search for a pupation site.

    In a laboratory setting, the fourth- and fifth-instar stages of the caterpillar showed signs of aggressive behavior with lower food availability. Attacked caterpillars were found to be attacked when it was feeding on milkweed leaves, and the caterpillar attacked when it was foraging for milkweed. [54] This demonstrates the aggressive behavior of monarch caterpillars due to the availability of milkweed.

    Pupa Edit

    To prepare for the pupa or chrysalis stage, the caterpillar chooses a safe place for pupation, where it spins a silk pad on a downward-facing horizontal surface. At this point, it turns around and securely latches on with its last pair of hindlegs and hangs upside down, in the form of the letter J. After "J-hanging" for about 12–16 hours, it will suddenly straighten out its body and go into peristalsis some seconds before its skin splits behind its head. It then sheds its skin over a period of a few minutes, revealing a green chrysalis. At first, the chrysalis is long, soft, and somewhat amorphous, but over a few hours it compacts into its distinct shape – an opaque, pale-green chrysalis with small golden dots near the bottom, and a gold-and-black rim around the dorsal side near the top. [55] At first, its exoskeleton is soft and fragile, but it hardens and becomes more durable within about a day. At this point, it is about 2.5 cm (1") long and 10–12 mm (3/8–7/16") wide, weighing about 1.2 grams. At normal summer temperatures, it matures in 8–15 days (usually 11–12 days). During this pupal stage, the adult butterfly forms inside. A day or so before emerging, the exoskeleton first becomes translucent and the chrysalis more bluish. Finally, within 12 hours or so, it becomes transparent, revealing the black and orange colors of the butterfly inside before it ecloses (emerges). [56]

    Adult Edit

    An adult butterfly emerges after about two weeks as a chrysalis, and hangs upside down for a few hours until its wings are dry. Fluids are pumped into the wings, which expand, dry, and stiffen. The monarch extends and retracts its wings, and once conditions allow, flies and feeds on a variety of nectar plants. During the breeding season, adults reach sexual maturity in four or five days. However, the migrating generation does not reach maturity until overwintering is complete. [57] Monarchs typically live for two to five weeks during their breeding season. [10] : (pp22–23) Larvae growing in high densities are smaller, have lower survival, and weigh less as adults compared with those growing in lower densities. [58] Monarch metamorphosis from egg to adult occurs during the warm summer temperatures in as little as 25 days, extending to as many as seven weeks during cool spring conditions. During the development, both larvae and their milkweed hosts are vulnerable to weather extremes, predators, parasites and diseases commonly fewer than 10% of monarch eggs and caterpillars survive. [10] : (pp21–22) However, this is a natural attrition rate for most butterflies, since they are low on the food chain.

    Reproduction Edit

    Females and males typically mate more than once. Females that mate several times lay more eggs. [59] Mating for the overwintering populations occurs in the spring, prior to dispersion. Mating is less dependent on pheromones than other species in its genus. [60] Male search and capture strategies may influence copulatory success, and human-induced changes to the habitat can influence monarch mating activity at overwintering sites. [61]

    Courtship occurs in two phases. During the aerial phase, a male pursues and often forces a female to the ground. During the ground phase, the butterflies copulate and remain attached for about 30 to 60 minutes. [62] Only 30% of mating attempts end in copulation, suggesting that females may be able to avoid mating, though some have more success than others. [63] [64] During copulation, a male transfers his spermatophore to a female. Along with sperm, the spermatophore provides a female with nutrition, which aids her in egg laying. An increase in spermatophore size increases the fecundity of female monarchs. Males that produce larger spermatophores also fertilize more females' eggs. [65]

    Pictorial life cycle Edit

    The host plants used by the monarch caterpillar include:

    • Asclepias angustifolia – Arizona milkweed [66]
    • Asclepias asperula – antelope horns milkweed [66]
    • Asclepias californica – California milkweed [66]
    • Asclepias cordifolia – heartleaf milkweed [66]
    • Asclepias curassavica
    • Asclepias eriocarpa – woolly pod milkweed [66]
    • Asclepias erosa – desert milkweed [66]
    • Asclepias exaltata – poke milkweed [66]
    • Asclepias fascicularis – Mexican whorled milkweed [66]
    • Asclepias humistrata – sandhill/pinewoods milkweed [66]
    • Asclepias incarnata – swamp milkweed [66]
    • Asclepias nivea – Caribbean milkweed [67]
    • Asclepias oenotheroide – zizotes milkweed [66]
    • Asclepias perennis – aquatic milkweed [66]
    • Asclepias speciosa – showy milkweed [66]
    • Asclepias subulata – rush milkweed [66]
    • Asclepias syriaca – common milkweed [66][68]
    • Asclepias tuberosa – butterfly weed [66]
    • Asclepias variegata – white milkweed [66]
    • Asclepias verticillata – whorled milkweed [66]
    • Asclepias vestita – woolly milkweed [66]
    • Asclepias viridis – green antelopehorn milkweed [66]
    • Calotropis gigantea – crown flower [69]
    • Calotropis procera
    • Cynanchum laeve – sand vine milkweed [70]
    • Sarcostemma clausa – white vine [35][71]

    Asclepias curassavica, or tropical milkweed, is often planted as an ornamental in butterfly gardens. Year-round plantings in the USA are controversial and criticised, as they may be the cause of new overwintering sites along the U.S. Gulf Coast, leading to year-round breeding of monarchs. [72] This is thought to adversely affect migration patterns, and to cause a dramatic buildup of the dangerous parasite, Ophryocystis elektroscirrha. [73] New research also has shown that monarch larvae reared on tropical milkweed show reduced migratory development (reproductive diapause), and when migratory adults are exposed to tropical milkweed, it stimulates reproductive tissue growth. [74]

    Although larvae eat only milkweed, adult monarchs feed on the nectar of many plants including:

    • Apocynum cannabinum – Indian hemp
    • Asclepias sp. – milkweeds
    • Aster sp. – asters
    • Cirsium sp. – thistles
    • Daucus carota – wild carrot
    • Dipsacus sylvestris – teasel
    • Echinacea sp. – coneflowers
    • Erigeron canadensis – horseweed
    • Eupatorium maculatum – spotted Joe-Pye weed
    • Eupatorium perfoliatum – common boneset
    • Hesperis matronalis – dame's rocket
    • Liatris sp. – blazing stars
    • Medicago sativa – alfalfa
    • Solidago sp. – goldenrod
    • Syringa vulgaris – lilac
    • Trifolium pratense – red clover
    • Vernonia altissima – tall ironweed [44]

    Monarchs obtain moisture and minerals from damp soil and wet gravel, a behavior known as mud-puddling. The monarch has also been noticed puddling at an oil stain on pavement. [44]

    In North America, monarchs migrate both north and south on an annual basis, in a long-distance journey that is fraught with risks. [4] The population east of the Rocky Mountains attempts to migrate to the sanctuaries of the Mariposa Monarca Biosphere Reserve in the Mexican state of Michoacán and parts of Florida. The western population tries to reach overwintering destinations in various coastal sites in central and southern California. The overwintered population of those east of the Rockies may reach as far north as Texas and Oklahoma during the spring migration. The second, third and fourth generations return to their northern locations in the United States and Canada in the spring. [75] Captive-raised monarchs appear capable of migrating to overwintering sites in Mexico, [76] though they have a much lower migratory success rate than wild monarchs do. [77] See section on captive-rearing below. Monarch overwintering sites have been discovered recently in Arizona. [78] Monarchs from the eastern US generally migrate longer distances than monarchs from the western US. [79]

    Physiological experiments suggest that monarch butterflies view the world through a tetrachromatic system. [80] Like humans, their retina contain three types of opsin proteins, expressed in distinct photoreceptor cells, each of which absorbs light at a different wavelength. Unlike humans, one of those types of photoreceptor cells corresponds to a wavelength in the ultraviolet range the other two correspond to blue and green. [81] In addition to these three photoreceptors cells in the main retina, monarch butterfly eyes contain orange filtering pigments that filter the light reaching some but not all green-absorbing opsins, thereby making a fourth photoreceptor cell sensitive to longer wavelength light. [80] The combination of filtered and unfiltered green opsins permits the butterflies to distinguish yellow from orange colors. [80] The ultraviolet opsin protein has also been detected in the dorsal rim region of monarch eyes. One study suggests that this allows the butterflies the ability to detect ultraviolet polarized skylight in order to orient themselves with the sun for their long migratory flight. [82]

    These butterflies are capable of distinguishing colors based on their wavelength only, and not based on intensity this phenomenon is termed "true color vision". This is important for many butterfly behaviors, including seeking nectar for nourishment, choosing a mate, and finding milkweed to lay eggs on. One study found that floral color is more easily recognized at a distance by butterflies searching for nectar than floral shape. This is may be because flowers have highly contrasting colors to the green background of a vegetative landscape. [83] On the other hand, leaf shape is important for oviposition so that the butterflies can ensure their eggs are being laid on milkweed.

    Beyond the perception of color, the ability to remember certain colors is essential in the life of monarch butterflies. Researchers have found that these insects can easily learn to associate color and, to a lesser extent shape, with sugary food rewards. When searching for nectar, color is the first cue that draws the insect's attention toward a potential food source, and shape is a secondary characteristic that promotes the process. When searching for a place to lay one's eggs, the roles of color and shape are switched. There may also be a difference between male and female butterflies from other species in terms of the ability to learn certain colors however, there is no differences between the sexes for monarch butterflies. [83]

    In both caterpillar and butterfly form, monarchs are aposematic, warding off predators with a bright display of contrasting colors to warn potential predators of their undesirable taste and poisonous characteristics. One monarch researcher emphasizes that predation on eggs, larvae or adults is natural, since monarchs are part of the food chain, thus people should not take steps to kill predators of monarchs. [84]

    Larvae feed exclusively on milkweed and consume protective cardiac glycosides. Toxin levels in Asclepias species vary. Not all monarchs are unpalatable, but exhibit Batesian or automimics. Cardiac glycosides levels are higher in the abdomen and wings. Some predators can differentiate between these parts and consume the most palatable ones. [85]

    Butterfly weed (Asclepias tuberosa) lacks significant amounts of cardiac glycosides, but instead contains other types of toxic glycosides, including pregnanes. [86] This difference may reduce the toxicity of monarchs whose larvae feed on that milkweed species, as a naturalist has reported that monarch caterpillars do not favor the plant. [87] Some other milkweeds may have similar characteristics.

    Types of predators Edit

    While monarchs have a wide range of natural predators, none of these are suspected of causing harm to the overall population, or are the cause of the long-term declines in winter colony sizes.

    Several species of birds have acquired methods that allow them to ingest monarchs without experiencing the ill effects associated with the cardiac glycosides. The oriole is able to eat the monarch through an exaptation of its feeding behavior that gives it the ability to identify cardenolides by taste and reject them. [88] The black-headed grosbeak, on the other hand, has developed an insensitivity to secondary plant poisons that allows it to ingest monarchs without vomiting. As a result, orioles and grosbeaks will periodically have high levels of cardenolides in their bodies, and they will be forced to go on periods of reduced monarch consumption. This cycle effectively reduces potential predation of monarchs by 50 percent and indicates that monarch aposematism has a legitimate purpose. [88] Other bird predators include brown thrashers, grackles, robins, cardinals, sparrows, scrub jays, and pinyon jays. [85]

    On Oahu, a white morph of the monarch has emerged. This is because of the introduction, in 1965 and 1966, of two bulbul species, Pycnonotus cafer and Pycnonotus jocosus. They are now the most common insectivore birds, and probably the only ones preying on insects as large as the monarch. Monarchs in Hawaii are known to have low cardiac glycoside levels, but the birds may also be tolerant of the chemical. The two species hunt the larvae and some pupae from the branches and undersides of leaves in milkweed bushes. The bulbuls also eat resting and ovipositing adults, but rarely flying ones. Because of its color, the white morph has a higher survival rate than the orange one. This is either because of apostatic selection (i.e., the birds have learned the orange monarchs can be eaten), because of camouflage (the white morph matches the white pubescence of milkweed or the patches of light shining through foliage), or because the white morph does not fit the bird's search image of a typical monarch, so is thus avoided. [89]

    Some mice, particularly the black-eared mouse (Peromyscus melanotis) are able to tolerate large doses of cardenolides and are able to eat monarchs. [90] Overwintering adults become less toxic over time making them more vulnerable to predators. In Mexico, about 14% of the overwintering monarchs are eaten by birds and mice and black-eared mice will eat up to 40 monarchs per night. [43] [90]

    In North America, eggs and first-instar larvae of the monarch are eaten by larvae and adults of the introduced Asian lady beetle (Harmonia axyridis). [91] The Chinese mantis (Tenodera sinensis) will consume the larvae once the gut is removed thus avoiding cardenolides. [92] Predatory wasps commonly consume larvae, [93] though large larvae may avoid wasp predation by dropping from the plant or by jerking their bodies. [94]

    Aposematism Edit

    Monarchs are foul tasting and poisonous due to the presence of cardenolides in their bodies, which the caterpillars ingest as they feed on milkweed. [60] Monarchs and other cardenolide resistant insects rely on a resistant form of the Na+/ K+-ATPase enzyme to tolerate significantly higher concentrations of cardenolides than nonresistant species. [95] By ingesting a large amount of plants in the genus Asclepias, primarily milkweed, monarch caterpillars are able to sequester cardiac glycosides, or more specifically cardenolides, which are steroids that act in heart-arresting ways similar to digitalis. [96] It has been found that monarchs are able to sequester cardenolides most effectively from plants of intermediate cardenolide content rather than those of high or low content. [97]

    Additional studies have shown that different species of milkweed have different effects on growth, virulence, and transmission of parasites. [98] One species, Asclepias curassavica, appears to reduce the symptoms of Ophryocystis elektroscirrha (OE) infection. There are two possible explanations for this: that it promotes overall monarch health to boost the monarch's immune system or that chemicals from the plant have a direct negative effect on the OE parasites. [98] A. curassavica does not cure or prevent the infection with OE, it merely allows infected monarchs to live longer, and this would allow infected monarchs to spread the OE spores for longer periods. For the average home butterfly garden, this scenario will only add more OE to the local population. [99]

    After the caterpillar becomes a butterfly, the toxins shift to different parts of the body. Since many birds attack the wings of the butterfly, having three times the cardiac glycosides in the wings leaves predators with a very foul taste and may prevent them from ever ingesting the body of the butterfly. [96] In order to combat predators that remove the wings only to ingest the abdomen, monarchs keep the most potent cardiac glycosides in their abdomens. [100]

    Mimicry Edit

    Monarchs share the defense of noxious taste with the similar-appearing viceroy butterfly in what is perhaps one of the most well-known examples of mimicry. Though long purported to be an example of Batesian mimicry, the viceroy is actually reportedly more unpalatable than the monarch, making this a case of Müllerian mimicry. [101]

    The monarch is the state insect of Alabama, [102] Idaho, [103] Illinois, [104] Minnesota, [105] Texas, [106] Vermont, [107] and West Virginia. [108] Legislation was introduced to make it the national insect of the United States, [109] but this failed in 1989 [110] and again in 1991. [111]

    A growing number of homeowners are establishing butterfly gardens monarchs can be attracted by cultivating a butterfly garden with specific milkweed species and nectar plants. Efforts are underway to establish these monarch waystations. [112]

    An IMAX film, Flight of the Butterflies, describes the story of the Urquharts, Brugger and Trail to document the then unknown monarch migration to Mexican overwintering areas. [113]

    Sanctuaries and reserves have been created at overwintering locations in Mexico and California to limit habitat destruction. These sites can generate significant tourism revenue. [114] However, with less tourism, monarch butterflies will have a higher survival rate because they show more protein content and a higher value of immune response and oxidative defense. [115]

    Organizations and individuals participate in tagging programs. Tagging information is used to study migration patterns. [116]

    The 2012 novel by Barbara Kingsolver, Flight Behavior, deals with the appearance of a large population in the Appalachians. [117]

    Captive rearing Edit

    One of the most direct ways humans are interacting with monarchs is by rearing them in captivity, which has become increasingly popular, although there are risks to this activity, and this has become a controversial topic. On one hand there are many positive aspects of captive rearing. Monarchs are bred in schools and used for butterfly releases at hospices, memorial events and weddings. [118] Memorial services for the September 11 attacks include the release of captive-bred monarchs. [119] [120] [121] Monarchs are used in schools and nature centers for educational purposes. [122] Many homeowners raise monarchs in captivity as a hobby and for educational purposes. [123]

    On the other hand this practice becomes problematic when monarchs are "mass-reared". Stories in the Huffington Post in 2015 and Discover magazine in 2016 have summarized the controversy around this issue. [124] [125] The frequent media reports of monarch declines has encouraged many homeowners to attempt to rear as many monarchs as possible in their homes and then release them to the wild in an effort to "boost the monarch population". Some individuals have taken this practice to the extreme, with massive operations that rear thousands of monarchs at once, like one in Linn County, Iowa. [126] However, the practice of rearing "large" numbers of monarchs in captivity for release into the wild is not condoned by monarch scientists, because of the risks of genetic issues and disease spread. [127] One of the biggest concerns of mass-rearing is the potential for spreading the monarch parasite, Ophryocystis elektroscirrha, into the wild. This parasite can rapidly build up in captive monarchs, especially if they are housed together. The spores of the parasite also can quickly contaminate all housing equipment, so that all subsequent monarchs reared in the same containers then become infected. One researcher stated that rearing more than 100 monarchs constitutes "mass-rearing" and should not be done. [128]

    In addition to the disease risks, researchers believe these captive-reared monarchs are not as fit as wild ones, owing to the unnatural conditions they are raised in. Homeowners often raise monarchs in plastic or glass containers in their kitchens, basements, porches, etc., and under artificial lighting and controlled temperatures. Such conditions would not mimic what the monarchs are used to in the wild, and may result in adult monarchs that are unsuited for the realities of their wild existence. In support of this, a recent study by a citizen scientist found that captive-reared monarchs have a lower migration success rate than wild monarchs do. [77]

    A study published in 2019 shed light on the fitness of captive-reared monarchs, by testing reared and wild monarchs on a tethered flight apparatus that assessed navigational ability. [129] In that study, monarchs that were reared to adulthood in artificial conditions showed a reduction in navigational ability. This happened even with monarchs that were brought into captivity from the wild for a few days. A few captive-reared monarchs did show proper navigation. This study revealed the fragility of monarch development: if the conditions are not suitable, their ability to properly migrate could be impaired. The same study also examined the genetics of a collection of reared monarchs purchased from a butterfly breeder, and found they were dramatically different from wild monarchs, so much so that the lead author described them as "franken-monarchs". [130]

    An unpublished study in 2019 compared behavior of captive-reared versus wild monarch larvae. [131] The study showed that reared larvae exhibited more defensive behavior than wild larvae. The reason for this is unknown, but it could relate to the fact that reared larvae are frequently handled and/or disturbed.

    The monarch was the first butterfly to have its genome sequenced. [10] : (p12) The 273-million base pair draft sequence includes a set of 16,866 protein-coding genes. The genome provides researchers insights into migratory behavior, the circadian clock, juvenile hormone pathways and microRNAs that are differentially expressed between summer and migratory monarchs. [132] [133] [134] More recently, the genetic basis of monarch migration and warning coloration has been described. [135]

    There is no genetic differentiation between the migratory populations of eastern and western North America. [10] : (p16) Recent research has identified the specific areas in the genome of the monarch that regulate migration. There appears to be no genetic difference between a migrating and nonmigrating monarch but the gene is expressed in migrating monarchs but not expressed in nonmigrating monarchs. [33]

    The monarch butterfly is not currently listed under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) or protected specifically under U.S. domestic laws. [136] On 14 August 2014, the Center for Biological Diversity and the Center for Food Safety filed a legal petition requesting Endangered Species Act protection for the monarch and its habitat, [10] based largely on the long-term trends observed at overwintering sites. The U.S. Fish and Wildlife Service (FWS) initiated a status review of the monarch butterfly under the Endangered Species Act with a due date for information submission of 3 March 2015, later extended to 2020. On December 15, 2020, the FWS ruled that adding the butterfly to the list of threatened and endangered species was “warranted-but-precluded” because it needed to devote its resources to 161 higher-priority species. [137]

    The number of monarchs overwintering in Mexico has shown a long-term downward trend. Since 1995, coverage numbers have been as high as 18 hectares (44 acres) during the winter of 1996–1997, but on average about 6 hectares (15 acres). Coverage declined to its lowest point to date (0.67 hectares (1.66 acres)) during the winter of 2013–2014, but rebounded to 4.01 hectares (10 acres) in 2015–2016. The average population of monarchs in 2016 was estimated at 200 million. Historically, on average there are 300 million monarchs. The 2016 increase was attributed to favorable breeding conditions in the summer of 2015. However, coverage declined by 27% to 2.91 hectares (7.19 acres) during the winter of 2016–2017. Some believe this was because of a storm that had occurred during March 2016 in the monarchs' previous overwintering season, [138] though this seems unlikely since most current research shows that the overwintering colony sizes do not predict the size of the next summer breeding population. [139]

    A study in 2016 claimed that the long-term trend in the size of the overwintering sites is cause for concern. After a ten-fold drop in the overwintering numbers of the eastern monarch butterfly population over the last decade, this study claimed there was an 11%–57% probability that this population will go quasi-extinct over the next 20 years. [140] According to Xerces Society, the monarch population in California decreased 86 percent in 2018, going from millions of butterflies to tens of thousands of butterflies. [141] In Xerces annual winter count of 2021 a significant decline in the California population. One Pacific Grove site did not have a single monarch butterfly. The primary explanation for this is the destruction of the butterfly's milkweed habitats. [142]

    In Ontario, Canada, the monarch butterfly is listed as a species of special concern. [143] In fall 2016, the Committee on the Status of Endangered Wildlife in Canada proposed that the monarch be listed as endangered in Canada, as opposed to its current listing as a "species of concern" in that country. This move, once enacted, would protect critical monarch habitat in Canada, such as major fall accumulation areas in southern Ontario, but it would also have implications for citizen scientists who work with monarchs, and for classroom activities. If the monarch were federally protected in Canada, these activities could be limited, or require federal permits. [144] In Nova Scotia, the monarch is listed as endangered at the provincial level, as of 2017. This decision (as well as the Ontario decision) appears to be because of the presumption that the overwintering colony declines in Mexico translate into declines in the breeding range in Canada. [145] Two recent studies have been conducted examining long-term trends in monarch abundance in Canada, using either butterfly atlas records [146] or citizen science butterfly surveys, [147] and neither shows evidence of a population decline in Canada.

    There is increasing concern related to the ongoing decline of monarchs at their overwintering sites based on a 2014 twenty-year comparison, the overwintering numbers west of the Rocky Mountains have dropped more than 50 percent since 1997 and the overwintering numbers east of the Rockies have declined by more than 90 percent since 1995. [10]

    In February 2015, the U.S. Fish and Wildlife Service provided a statistic showing that nearly a billion monarchs have vanished from the overwintering sites since 1990. At that time, one of the main reasons cited was the herbicides used by farmers and homeowners on milkweed, a plant used as a food source, a home and a nursery by the monarchs. [148] A 2016 study also attributed the last decade's ten-fold decline in overwintering numbers of the eastern monarch population to the loss of breeding habitat, namely the many species of milkweed (Asclepias species) that developing larvae require for food however, scientists believe there are other factors as well. A number of researchers believe milkweed loss during the breeding season is the cause because declines in milkweed abundance are highly correlated with the adoption of herbicide-tolerant genetically modified corn and soybeans, which now constitute 89% and 94% of these crops, respectively, in the U.S. [140] However, correlative evidence does not prove causation, and other possible causes of the overwintering declines have been proposed. A 2018 study has suggested that the decline in milkweed predates the arrival of GM crops. [149]

    Habitat loss due to herbicide use Edit

    A number of conservationists attribute the disappearance of milkweed species to agricultural practices in the Midwest, where genetically modified seeds are bred to resist herbicides that eliminate milkweed nearby. Growers eliminate milkweed that previously grew between the rows of food crops. Corn and soybeans are resistant to the effect of the herbicide glyphosate. The increased use of these crop strains is correlated with the decline in monarch populations between 1999 and 2010. [150] [151] Chip Taylor, director of Monarch Watch at the University of Kansas, said the Midwest milkweed habitat "is virtually gone" with 120–150 million acres lost. [152] [153] To help fight this problem, Monarch Watch encourages the planting of "Monarch Waystations". [123] The Natural Resources Defense Council filed a suit in 2015 against the EPA, in which it is argued that the agency ignored warnings about the dangers of glyphosate usage for monarchs. [154]

    Losses during migration Edit

    While herbicide use has been proposed as one factor causing the decline in overwintering numbers of eastern monarchs, it is not the only possibility. Another is that the monarchs are experiencing problems reaching Mexico. This idea has been embraced by a number of leading monarch researchers, largely because of recent evidence showing that the number of breeding (adult) monarchs has not declined in the last two decades, based on long-term citizen science data. [155] [156] [157] The lack of long-term declines in the numbers of breeding, and migratory monarchs, yet the clear declines in overwintering numbers, implies there is a disconnect between these life stages, that must be growing. One expert has proposed that a large and growing threat to migrating monarchs is mortality from car strikes. [158] A study of road mortality in northern Mexico, published in 2019, showed very high mortality from just two "hotspots" each year, amounting to 200,000 monarchs killed. [159]

    Parasites Edit

    Parasites include the tachinid flies Sturmia convergens [160] and Lespesia archippivora. Lesperia-parasitized butterfly larvae suspend, but die prior to pupation. The fly's maggot lowers itself to the ground, forms a brown puparium and then emerges as an adult. [161]

    Monarch chrysalises are parasitized by pteromalid wasps, specifically Pteromalus cassotis. [162] These wasps lay their eggs in the pupae while the chrysalis is still soft. Up to 400 adults emerge from the chrysalis after 14–20 days, [162] killing the monarch.

    The bacterium Micrococcus flacidifex danai also infects larvae. Just before pupation, the larvae migrate to a horizontal surface and die a few hours later, attached only by one pair of prolegs, with the thorax and abdomen hanging limp. The body turns black shortly after. The bacterium Pseudomonas aeruginosa has no invasive powers, but causes secondary infections in weakened insects. It is a common cause of death in laboratory-reared insects. [161]

    The protozoan Ophryocystis elektroscirrha is another parasite of the monarch. It infects the subcutaneous tissues and propagates by spores formed during the pupal stage. The spores are found over all of the body of infected butterflies, with the greatest number on the abdomen. These spores are passed, from female to caterpillar, when spores rub off during egg laying and are then ingested by caterpillars. Severely infected individuals are weak, unable to expand their wings, or unable to eclose, and have shortened lifespans, but parasite levels vary in populations. This is not the case in laboratory rearing, where after a few generations, all individuals can be infected. [163] Infection with this parasite creates an effect known as culling whereby migrating monarchs that are infected are less likely to complete the migration. This results in overwintering populations with lower parasite loads. [164] Owners of commercial butterfly breeding operations claim that they take steps to control this parasite in their practices, [165] although this claim is doubted by many scientists who study monarchs. [166]

    Confusion of host plants Edit

    The black swallow-wort (Cynanchum louiseae) and pale swallow-wort (Cynanchum rossicum) plants are problematic for monarchs in North America. Monarchs lay their eggs on these relatives of native vining milkweed (Cynanchum laeve) because they produce stimuli similar to milkweed. Once the eggs hatch, the caterpillars are poisoned by the toxicity of this invasive plant from Europe. [167]

    Loss of overwintering habitat Edit

    The area of forest occupied has been declining and reached its lowest level in two decades in 2013. The decline is continuing but is expected to increase during the 2013–2014 season. Mexican environmental authorities continue to monitor illegal logging of the oyamel trees. The oyamel is a major species of evergreen on which the overwintering butterflies spend a significant time during their winter diapause, or suspended development. [168]

    A 2014 study acknowledged that while "the protection of overwintering habitat has no doubt gone a long way towards conserving monarchs that breed throughout eastern North America", their research indicates that habitat loss on breeding grounds in the United States is the main cause of both recent and projected population declines. [169]

    Climate Edit

    Climate variations during the fall and summer affect butterfly reproduction. Rainfall, and freezing temperatures affect milkweed growth. Omar Vidal, director general of WWF-Mexico, said "The monarch's lifecycle depends on the climatic conditions in the places where they breed. Eggs, larvae and pupae develop more quickly in milder conditions. Temperatures above 35 °C (95 °F) can be lethal for larvae, and eggs dry out in hot, arid conditions, causing a drastic decrease in hatch rate." [170] If a monarch's body temperatures is below 30 °C (86 °F) a monarch cannot fly. To warm up they will sit in the sun or rapidly shiver their wings to warm themselves. [171]

    There is concern that climate change will dramatically affect the monarch migration. A study from 2015 examined the impact of warming temperatures on the breeding range of the monarch, and showed that in the next 50 years the monarch host plant will expand its range further north into Canada, and that the monarchs will follow this. [172] While this will expand the breeding locations of the monarch, this will also have the effect of increasing the distance that monarchs must travel to reach their overwintering destination in Mexico, and this could result in greater mortality during the migration. [173]

    Milkweeds grown at increased temperatures have been shown to contain higher cardenolide concentrations making the leaves too toxic for the monarch caterpillars, but these increased concentrations are likely in response to increased insect herbivory which is also caused by the increased temperatures, so it is unknown whether increased temperatures in isolation will make milkweed too toxic for monarch caterpillars. [174] Additionally, milkweed grown at carbon dioxide levels of 760 parts per million (ppm) plants were found to produce a different mix of the toxic cardenolides, one that was less effective against monarch parasites. [175]

    Although numbers of breeding monarchs in eastern North America have apparently not decreased, reports of declining numbers of overwintering butterflies have inspired efforts to conserve the species. [155] [156] [157] Because of concerns over the overwintering numbers, the Center for Biological Diversity, the Center for Food Safety, the Xerces Society and Lincoln Brower have filed a petition to the United States Department of the Interior to protect the monarch by having it federally protected. [10]

    On 20 June 2014, President Barack Obama issued a presidential memorandum entitled "Creating a Federal Strategy to Promote the Health of Honey Bees and Other Pollinators". The memorandum established a Pollinator Health Task Force, to be co-chaired by the Secretary of Agriculture and the Administrator of the Environmental Protection Agency, and stated:

    The number of migrating Monarch butterflies sank to the lowest recorded population level in 2013–14, and there is an imminent risk of failed migration. [176]

    In May 2015, the Pollinator Health Task Force issued a "National Strategy to Promote the Health of Honey Bees and Other Pollinators". The strategy lays out current and planned federal actions to achieve three goals, two of which are:

    • Monarch Butterflies: Increase the Eastern population of the monarch butterfly to 225 million butterflies occupying an area of approximately 15 acres (6 hectares) in the overwintering grounds in Mexico, through domestic/international actions and public-private partnerships, by 2020.
    • Pollinator Habitat Acreage: Restore or enhance 7 million acres of land for pollinators over the next 5 years through Federal actions and public/private partnerships.

    Many of the priority projects that the national strategy identifies will focus on the I-35 corridor extending for 1,500 miles (2,400 km) from Texas to Minnesota that provides spring and summer breeding habitats in the monarch's key migration corridor. [177]

    There have been a number of national and local efforts underway to establish pollinator habitat along highways and roadways, although this effort is controversial. Conservationists are lobbying transportation departments and utilities to reduce their use of herbicides and specifically encourage milkweed to grow along roadways and power lines. Reducing roadside mowing and application of herbicides during the butterfly breeding season will encourage milkweed growth. [178] Conservationists lobby agriculture companies to set aside areas that remain unsprayed to allow the butterflies to breed. [151] This practice is controversial because of the high risk of butterfly mortality near roads, as several studies have shown that millions of monarchs and other butterflies are killed by cars every year. [158] There is also evidence that monarch larvae living near roads experience physiological stress conditions, as evidenced by elevations in their heart rate. [179]

    A 2020 resource from the Cooperative Research Programs of the Transportation Research Board developed products for roadway corridors to provide habitat for monarch butterflies and developed tools for roadside managers to optimize potential habitat for monarch butterflies in their road right-of-ways. [180]

    Butterfly gardening Edit

    While there are few scientific studies on the subject, the practice of butterfly gardening and creating "Monarch Waystations" is commonly thought to increase the populations of butterflies. [181] Efforts to increase monarch populations by establishing butterfly gardens and waystations require particular attention to the butterfly's food preferences and population cycles, as well to the conditions needed to propagate milkweed.

    For example, in the Washington, D.C. area and elsewhere in the northeastern United States, monarchs prefer to reproduce on common milkweed (Asclepias syriaca), especially when its foliage is soft and fresh. Because monarch reproduction in that area peaks in late summer when milkweed foliage is old and tough, A. syriaca needs to be cut back in June through August to assure that it will be regrowing rapidly when monarch reproduction reaches its peak. [66] [182] In addition, milkweed seed may need a period of cold treatment (cold stratification) before it will germinate. [183]

    Although monarch caterpillars will feed on butterfly weed (Asclepias tuberosa) in butterfly gardens, the plant has rough leaves and is typically not a heavily used host plant. The plant is therefore less suitable for use in butterfly gardens and monarch waystations than are other milkweed species. [184] In addition, the plant's lack of cardiac glycosides may also make the plant unattractive to egg-laying monarchs. [87]

    Misconceptions About Hornworm Parasites

    And while we're talking about these hornworm parasitoids, let's clear up a few misconceptions about them:

    "Those white things on the hornworm are parasite eggs."

    No, they aren't. The braconid wasp injects her eggs into the caterpillar's body, under the skin, where you can't see them. Those white things on the hornworm's body are actually cocoons, the pupal stage of the braconid wasp. And if you watch them closely, you might get to see the tiny adult wasps emerging and flying away.

    "The wasps hatch from those cocoons and attack the hornworm."

    Wrong again. The adult wasps emerge from their cocoons, fly off and mate, and then the females look for new hornworm hosts in which to deposit its eggs. The hornworm "attack" is perpetrated by the wasp larvae that hatch from eggs inside the caterpillar's body. The damage to that caterpillar occurred well before those white cocoons were spun on its skin.

    What is the name of the bug that emerging from a wood chip like cocoon? - Biology

    Spruce beetle outbreaks cause extensive tree mortality and modify stand structure by reducing the average tree diameter, height, and stand density. Residual trees are often slow-growing small and intermediate-sized trees which eventually become dominant.

    Spruce beetle outbreaks can affect non-timber resources as well. For example, as mature spruce are killed, forage may increase, benefiting some wildlife species. But species that depend on mature spruce or clumps of spruce to meet habitat requirements may be adversely affected. There has been a significant change in fuel type and an increase in large woody debris accumulating on the forest floor following spruce beetle outbreaks in Alaska. Uncharacteristic, stand-replacing fires occurred in central Idaho spruce stands following ten years of spruce beetle outbreaks. Extensive spruce mortality can also affect water yields resulting in water increases in rivers, lakes, and streams because of reduced transpiration from dead and dying trees. Scenic quality may also be diminished throughout affected landscapes.

    On windthrown trees and logging residuals, spruce beetle attacks are readily detected on the lower surfaces of the material and should not be confused with engraver beetle (Ips spp.) attacks more commonly found on the upper surfaces.

    Some standing trees may be attacked on only one side of the bole, creating a "strip attack. " The infested area may die, but the tree usually remains alive, so the foliage does not discolor. Trees with "strip attacks" frequently are infested by subsequent spruce beetle generations and may host two or more generations simultaneously.

    During the first fall and winter following spruce beetle infestation, look for trees "debarked" by woodpeckers (fig. 3). Partially debarked, green trees are easily noticed. However, on trees without significant debarking, one must be relatively close to see sawdust in bark crevices and around the tree base.

    The needles of infested trees do not usually fade or discolor within the first year following attack. However, during the second summer, most needles turn yellowish-green or orange-red (Alaska). Some even remain green until the third summer, or up to 2 years after the initial infestation. The needles on separate branches of the same tree discolor at different times. Needles on infested trees commonly drop to the ground as a result of wind or thunderstorms the second summer after the tree was attacked, leaving the upper crowns of exposed twigs with a yellowish-orange to reddish hue later turning to grey.

    Spruce beetles are similar to other Dendroctonus beetles and, if no host material is present, can only be distinguished by microscopic examination. At first glance, spruce beetles may also be confused with Ips beetles in spruce. It is important to remember that the posterior margins of the wing covers on spruce beetles are evenly rounded, while Ips beetles have concave margins with teeth like projections.

    The eggs of the spruce beetle are oblong, pearly white, and 1/16 inch (1.5 mm) long. The cream colored larvae are stout, cylindrical, legless grubs that pass through four larval stages (instars) and reach a length of l/4 inch (6 mm) at maturity. The pupae are opaque white, inactive, and somewhat similar in size and shape to adults.

    However, throughout most of its range and in most seasons, two years are generally required for the spruce beetle to complete its life cycle. Although adults may emerge any time from May to October, depending on temperature, most attacks occur in early summer. Adult beetles attack host material soon after emerging. Adults that appear in August to October may represent a re-emergence of parent adults or a movement of maturing brood adults to hibernation sites.

    To deposit eggs, females bore through the outer bark of host trees and create egg galleries in the underlying phloem tissue. Eggs are laid on either side of the egg gallery (fig. 5). Egg galleries are slightly wider than the beetle and, except for the terminal portion, are packed with frass and boring dust. Egg gallery length ranges from about 2.5 to 12 inches (6 to 13 cm) (fig. 6). Eggs are usually deposited in short rows along alternate sides of the gallery in numbers ranging from 4 to 14 eggs per centimeter of gallery.

    During the second winter of the 2-year cycle in standing trees, some beetles overwinter in their pupal sites, others emerge, move to the base of the tree, and bore into the bark near the litter line to hibernate. During the second winter of the 2-year life cycle in standing trees, some beetles overwinter in their pupal sites but the majority, often as high as 95 percent, of the new adults emerge, move to the base of the tree, and bore into the bark near the litter line to overwinter. Overwintering at the base of the infested tree reduces predation by woodpeckers and reduces winter mortality due to extreme cold temperatures. In windthrown trees, most adults overwinter in place.

    Approximately 2 years after attack, adults emerge from overwintering sites and attack new host material.

    Stand Conditions Conducive To Infestations
    Endemic spruce beetle populations usually live in windthrown trees (fig. 7). When populations increase to high levels in downed trees, beetles may enter susceptible, large-diameter standing trees. Most outbreaks in standing timber originate in windthrown trees.

    In mature stands, larger diameter (> or = 18") trees usually are attacked first, an obvious characteristic denoting susceptibility to spruce beetle attack. If an infestation persists in a stand, smaller diameter trees are attacked. Recent evidence from Alaska indicates that tree diameter is important in determining susceptibility only when coupled with less-than-average radial growth in the preceding five years.

    In the Rocky Mountain area, susceptibility, or hazard, of a stand to spruce beetle attack is based on the physiographic location, tree diameter, basal area, and percentage of spruce in the canopy. Spruce stands are highly susceptible if they grow on well-drained sites in creek bottoms, have an average diameter-at breast-height (dbh) of 16 inches or more, have a basal area greater than 150 square feet per acre, and have more than 65 percent spruce in the canopy.

    In Alaska, susceptibility of spruce stand is based on average tree diameter, age of stand, condition of the stand, and proportion of spruce in the canopy. A spruce stand of old-growth or damaged larger host trees is very susceptible to spruce beetle attack particularly if larger diameter spruce trees have a slower-than-average growth rate, have an average dbh greater than 12 inches, and if the stand has more than 70 percent spruce.

    Susceptibility of a spruce stand to spruce beetle attack in British Columbia and the Northeastern United States is based on criteria similar to that used in the Rocky Mountains and Alaska.

    Hazard and risk (= probability of an outbreak) rating systems based on the stand and site conditions discussed above have been developed which enable managers to identify stand susceptibility to spruce beetle attack.

    Management Strategies
    Forest managers can develop various strategies to avoid or reduce resource losses to spruce beetles. Before developing a strategy, the forest manager must evaluate resource values and economics of management actions for each stand combined with overall management objectives. The beetle population level must also be considered because population levels will determine the priority of management actions and the type of strategy to be invoked.

    A principal strategy that should be considered for susceptible sites would consist of silvicultural treatments of moderate-high hazard stands that result in maintaining their health with a moderate growth rate. The first step in this strategy is to hazard-rate spruce stands, which will designate the most susceptible stands. Moderate-high hazard stands can then be treated using silvicultural strategies that reduce stand susceptibility. Infested logging residuals will not become a significant contributor to spruce beetle populations if stump height is kept below 18 inches (45 cm) and cull logs and tops are limbed, cut into short lengths, and left unshaded, unpiled, and exposed to sunlight. Silvicultural treatments have greater long-term effectiveness, because treatments modify stand conditions that contribute to spruce beetle population increases.

    Silvicultural strategies may be more effective if beetle populations are not immediately threatening resource values. If beetle populations are threatening, then strategies that include suppression methods are more appropriate. Suppression methods, including silvicultural, physical (fire & solar heat), and chemical measures, are available to forest managers for reducing spruce beetle populations. Some methods are suitable only for populations in windthrown host material other methods are better suited for infestations in standing trees. Most suppression methods are short-term responses to existing beetle populations and, therefore, address only an immediate need.

    Silvicultural Methods
    Sanitation overstory removal - Removal of all infested and susceptible spruce to encourage regeneration of a new vigorous stand. Sanitation partial cut includes the removal of infested and susceptible spruce to improve the growth of the residual stand. Sanitation partial cut removes most of the larger trees but may leave a residual stand that is below the recommended level of basal area. This residual stand may be more susceptible to windthrow. Pruning the lower 1/3 of the live crown of smaller diameter trees significantly reduces the susceptibility of spruce to beetle attack in Alaska.

    Trap trees are green trees with a dbh greater than 12 inches that are felled before beetle flight. Trap trees can absorb up to 10 times the number of spruce beetles that a standing tree will absorb. Once infested, trap trees must be removed.

    Trap trees shaded from direct sunlight attract the most beetles. Spruce beetles attack cool, shaded portions of the trap tree boles (fig. 8). Felled trees should not be delimbed. Limbs on the upper side of the bole provide shade while limbs on the underside permit the beetles to colonize the underside of the bole by keeping it off the ground.

    Past ratios of trap trees to infested standing trees have ranged from 1:2 to 1:10. Current ratios vary with the size of the green trees to be felled as traps compared to the number and size of infested trees and the existing beetle population.

    Physical Methods
    Solar heat involves exposing infested logging residuals or windthrow to direct sunlight to kill inhabiting larvae. To maximize brood mortality, all host material greater than eight inches dbh should be cut into 5-foot lengths. All branches and debris shading the host material should be removed. The infested material should be rotated at 2- week intervals during the summer to expose all surfaces. While using solar heat is effective on some sites in the Rocky Mountains, it is not effective in Alaska, because summer temperatures are not warm enough.

    Fire involves piling and burning infested logging residuals and windthrow to destroy inhabiting broods. The infested material is usually green and difficult to burn, but only the bark has to be burned to destroy the inhabiting brood.

    Chemical Methods
    Pheromones are chemical substances, produced by insects, that influence their behavior. Synthetic aggregating and anti-aggregating pheromones increase attractiveness of trap trees, attract beetles into trees to be cut, or discourage infestation of high-value trees. Aggregating pheromones are effectively used with trap trees. Under some circumstances, aggregating pheromones have also been used successfully in catchment traps to reduce small, isolated beetle populations.

    Insecticides, such as carbaryl and pyrethroids, can be applied to the boles of uninfested trees to kill attacking adults. In Alaska, carbaryl applied as a 2-percent spray has provided 100 percent protection from attacking beetles for at least 2 years.

    More information about the management of the spruce beetle may be obtained from the State Forester's office or the U.S. Department of Agriculture, Forest Service, Forest Health Protection.

    The publications listed in the references provide more information on the biology, ecology, and management of the spruce beetle.

    Alexander, R.R. 1986. Silvicultural systems and cutting methods for old-growth spruce-fir forests in the central and southern Rocky Mountains. Gen. Tech. Rep. RM-126. USDA Forest Serv., Rocky Mtn. Forest & Range Exp. Sta., Ft. Collins, CO. 33 p.

    British Columbia Ministry of Forests. 1981. Spruce beetle management seminar and workshop. In: Proceedings, 1980 seminar and workshop 1980 October 7-8 Prince George, B.C. Pest Mgmt. Rep. No. 1, Province of British Columbia, Ministry of Forests, Victoria, B.C., Canada. 16 p.

    Gibson, K.E. 1984. Use of trap trees for the reduction of spruce beetle-caused mortality in old-growth Engelmann spruce stands in the Northern Region. Rep. No. 84-10. USDA Forest Serv., Northern Region, Missoula, MT. 11 p.

    Hard, J.S. Holsten, E.H. 1985. Managing white and Lutz spruce stands in south central Alaska for increased resistance to spruce beetle. Gen. Tech. Rep. PNW-188. USDA Forest Serv., Pacific NW Forest & Range Exp. Sta., Portland, OR. 21 p.

    Hard, J.S. Werner, R.A. Holsten, E.H. 1983. Susceptibility of white spruce to attack by spruce beetles during the early years of an outbreak in Alaska. Can. J. For. Res. 13:678-684.

    Hodgkinson, R.S. 1985. Use of trap trees for spruce beetle management in British Columbia: 1979-1984. Pest Mgmt. Rep. No. 5., Province of British Columbia, Ministry of Forests, Victoria, B.C., Canada. 39 p.

    Holsten, E.H. 1990. Spruce beetle activity in Alaska: 1920-1989. Tech. Rep. R10-90-18. USDA Forest Serv., Alaska Region, Anchorage, AK. 28 p.

    Holsten, E.H. Werner, R.A. DeVelice, R.L. 1995. Effects of a spruce beetle (Coleoptera: Scolytidae) outbreak and fire on Lutz spruce in Alaska. Environ. Entomol. 88(6):1539-1547.

    Johnson, K.J. 1996. Effectiveness of carbaryl and pyrethroid insecticides for protection of Englemann spruce from attack by spruce beetles (Coleoptera: Scolytidae). MS Thesis. Utah State Univ., Logan, UT. 87p.

    Massey, C.L. Wygant, N.D. 1954. Biology and control of the Engelmann spruce beetle in Colorado. Agric. Cir. No. 944. USDA, Washington, D.C. 35 p.

    Reynolds, K.M. E.H. Holsten. 1994. Estimating priorities of risk factors for spruce beetle outbreaks. Can. J. For. Res. 24:3027-3033.

    Reynolds, K.M. E.H. Holsten. 1996. Classification of spruce beetle hazard in Lutz and Sitka spruce stands on the Kenai Peninsula, Alaska. For. Ecology and Management. 84:251-262.

    Reynolds, K.M. E.H. Holsten. 1997. SBexpert user guide (version 2.0): A knowledge-based decision-support system for spruce beetle management. Gen. Tech. Rep., PNW-GTR-401. USDA Forest Serv., Pacific NW Forest & Range Exp. Sta., Portland, OR. 62p.

    Schmid, J.M. Frye, R.H. 1976. Stand ratings for spruce beetles. Res. Note RM-309. USDA Forest Serv., Rocky Mtn. Forest & Range Exp. Sta., Ft. Collins, CO. 4 p.

    Schmid, J.M. Frye, R.H. 1977. Spruce beetle in the Rockies. Gen. Tech. Rep. RM-49. USDA Forest Serv., Rocky Mtn. Forest & Range Exp. Sta., Ft. Collins, CO. 38 p.

    Thier, R.W. 1994. Chronology of the current spruce beetle infestation on the Payette National Forest, Idaho. Rep. R4-94-02. USDA Forest Serv., Intermountain Region, Ogden, UT. 23p.

    Werner, R.A. Baker, B.H. Rush, P.A. 1977. The spruce beetle in white spruce forests of Alaska. Gen. Tech. Rep. PNW-61. USDA Forest Serv., Pacific NW Forest & Range Exp. Sta., Portland, OR. 13 p.

    Werner, R.A. Hastings, F.L. Holsten, E.H. Jones, A.S. 1986. Carbaryl and lindane protect white spruce from attack by spruce beetles (Coleoptera: Scolytidae) for three growing seasons. J. Econ. Entomol. 79:1121-1124.

    Apply pesticides so that they do not endanger humans, livestock, crops, beneficial insects, fish, and wildlife. Do not apply pesticides where there is danger of drift when honey bees or other pollinating insects are visiting plants, or in ways that may contaminate water or leave illegal residues. Avoid prolonged inhalation of pesticide sprays or dusts: wear protective clothing and equipment, if specified on the label. If your hands become contaminated with a pesticide, do not eat or drink until you have washed. In case a pesticide is swallowed or gets in the eyes, follow the first aid treatment given on the label, and get prompt medical attention. If a pesticide is spilled on your skin or clothing, remove clothing immediately and wash skin thoroughly.

    In the anime

    Main series

    Major appearances

    Team A.C.T.

    A Tyranitar was a member of Team A.C.T., who was considered for the job of rescuing Big Brother Pikachu in Pokémon Mystery Dungeon: Team Go-Getters Out of the Gate!. They were, however, occupied on another mission.


    In Celebi: The Voice of the Forest, a Tyranitar was captured in a Dark Ball and used by the Iron-Masked Marauder in his quest to capture Celebi.

    In Address Unown, when Ash and his friends entered the mind of Ash's Larvitar, they saw its memory of being separated from its Tyranitar mother. Larvitar returned to her mother in the following episode.

    In A Poached Ego, Rico's Pupitar evolved into a Tyranitar and immediately attacked Team Rocket while trying to steal Arbok, Weezing, and the horde of Ekans and Koffing that Rico had been seeking. However, Team Rocket fought back, giving Arbok, Weezing, and the Ekans and Koffing enough time to escape. Tyranitar was eventually taken care of by Officer Jenny's Growlithe.

    In Mewtwo — Prologue to Awakening, Dirk used a Tyranitar against Mewtwo. It eventually escaped when Mewtwo crushed its Poké Ball.

    A Tyranitar that can Mega Evolve into Mega Tyranitar appeared in Mega Evolution Special III.

    In Volcanion and the Mechanical Marvel, a Tyranitar that can Mega Evolve was under the control of Levi and Cherie's Mega Wave. It battled Ash's Pikachu and Noivern, as well as Volcanion. It was later freed from their control when Alva's Mega Wave Crystal was destroyed, and it escaped.

    In Finals Not for the Faint-Hearted!, Alain used a Tyranitar during the final round of the Lumiose Conference against Ash. It battled Pikachu but was soon defeated.

    In Not Caving Under Pressure!, a Tyranitar attacked a group of Alolan Sandshrew in an attempt to take over the Mount Lanakila cave they lived in. With Lillie's help, Tyranitar was defeated and sent running off.

    In Ivysaur's Mysterious Tower!, James pulled a Tyranitar from the Rocket Prize Master. They were used in an attempt to steal a horde of Bulbasaur and Ivysaur in Vermilion City.

    Minor appearances

    In Lucario and the Mystery of Mew, multiple Tyranitar were part of the feuding armies that were eventually placated by Sir Aaron in the past.

    A Tyranitar appeared in a fantasy in Pinch Healing!.

    In the opening sequence of Pokémon Ranger and the Temple of the Sea, Rebecca used a Tyranitar in a battle against Brendan's Swampert.

    In A Faux Oak Finish!, a Trainer's Tyranitar was agitated by a splinter in its foot. However, Professor Oak was able to connect with it and pull the splinter out.

    A Tyranitar appeared in the opening sequence of Zoroark: Master of Illusions.

    A robotic Tyranitar was used for a movie directed by Jules in An Epic Defense Force!.

    A Tyranitar that can Mega Evolve into Mega Tyranitar appeared in the opening of Mega Evolution Special I.

    A Tyranitar and its Mega Evolved form appeared in the opening sequence of Volcanion and the Mechanical Marvel.

    A soldier's Tyranitar appeared in a flashback in The Legend of X, Y, and Z!.

    In The Power of Us, a Tyranitar went on a rampage during the Pokémon Catch Race, but Ash was able to calm it down with Pikachu's help.

    Carpenter Ant Larvae

    Carpenter ants go through complete metamorphosis, passing through the egg, larval, pupal and adult stages.

    When male and female winged reproductives leave a colony, they mate. Soon after mating, females shed their wings and males die. Each wingless female will now look for moist locations where she will lay her first batch of eggs and establish a new colony.

    It takes an individual ant six to 12 weeks to develop from egg to adult, and it takes three to six years to develop an active and stable colony. This development timeline depends on a steady warm temperature. Colder weather can lengthen the process up to 10 months.

    Carpenter ant larvae are small, white, legless and grub-like young. During this stage, adult workers forage for food for the carpenter ant larvae.

    Carpenter ant larvae process the solid food given to them by workers and regurgitate it so that other ants can consume the liquid. Even at an early stage in their lives, carpenter ant larvae are necessary for their colonies to develop and survive. As long as a colony houses a queen, there will always be larvae developing within it.

    Free Pest Control Estimate. More Resources:

    Elevator pitches for each stock and basket

    For the even quicker version, see my threaded tweet (I also post ongoing coverage of these stocks on my Twitter account). While it's slightly longer than 280 characters, rest assured the investing thesis summaries below are still quick and high-level.

    iRobot is one of my favorite stocks because it checks so many of the boxes I like to see in a company.

    Strong balance sheet? Check

    Known primarily for its Roomba robot vacuums and Braava robot mops, its core business is already impressively profitable.

    But iRobot has the potential to be so much more than its current business or past growth indicates. Its competencies in robotics and artificial intelligence allow for tremendous optionality around home appliances and beyond.

    Upwork and Fiverr

    This is the dynamic duo of gig economy online marketplaces, standing ready to link businesses and individuals with just about any freelance skill you can think of: development, writing, graphic design -- even video game tutoring or celebrity impersonation.

    As work becomes more remote, more global, more freelance, and more flexible, these are platform plays positioned to profit.

    Upwork has more sales, but Fiverr has more recent growth, so it makes sense to bet on the overall trend as a two-pack.

    Redfin and Zillow

    These two home-buying/selling platforms are disrupting traditional real estate agents.

    They differ in their business models. Redfin is best described as a brokerage, Zillow as a marketplace Redfin is arguably more conservative, while Zillow could be seen as more aggressive.

    But each has the optionality to extract value in all aspects of the home buying/selling process as trillions of dollars change hands each year.

    Beyond Meat

    Beyond Meat's plant-based meat offerings are riding two rising trends: health consciousness and environmental sustainability.

    Founder and CEO Ethan Brown knows Beyond is in a race against the competition (both traditional and upstart) to establish itself as a name brand in the space. The business has been running at hyperspeed to establish distribution across supermarkets and restaurants, as well as directly to consumers.

    We could say much the same about Impossible Foods and its founder Patrick Brown (no relation), but it's a private company.

    There are few markets larger than the global meat market, and Beyond Meat is going after a bite of it.

    Connecting crafty makers with customers looking for something a bit more out of the ordinary than mainstream e-commerce fare, Etsy was growing nicely before the pandemic.

    During the pandemic, all e-commerce was given a huge boost, but Etsy absolutely skyrocketed, growing at more than twice the rate of overall e-commerce.

    Before the pandemic, management thought it had a 5% share of a $100 billion niche market. Now, based on its success, increased online adoption, and an expansion of what it believes people will buy from it, Etsy believes its total addressable market is measured in trillions, rather than billions.

    As you may notice throughout this list, powerful platforms get my attention. Make no mistake: Etsy is one.

    Because of this platform and brand strength, Etsy's growth opportunity appears to be much larger than its current market value.

    Already a growing force, telehealth got a big boost during the coronavirus pandemic. After all, the barrier to doing a remote doctor's visit is much higher than buying your first roll of toilet paper on Amazon.

    Teladoc is a leader in digital health and its merger with chronic condition specialist Livongo signals its intention to expand deep into the medical ecosystem.

    Pinterest is an oasis of positivity in a social media landscape that's grown increasingly depressing and divisive.

    That partially flows from what Pinterest is about: projects. Whether it's building a dream deck, baking a kid's birthday cake, or updating your wardrobe, Pinterest gives people visual inspiration for the things they want to get done.

    The knock against Pinterest, despite its solid community and sales growth, has been a lack of Facebook-level monetization.

    But that's what I love about Pinterest: It's got the platform and audience, and it's really easy to envision how seamless advertising, lead generation, and product placement could be when people are already there for suggestions.

    As streaming services (Netflix, Amazon Prime, Disney+, HBO Max, Peacock, The Roku Channel, etc.) push connected TV to new heights at the expense of traditional cable packages, Roku has set itself up as a winning platform. One with the size and leverage to pit each service against the others.

    It's gone beyond the boxes and dongles it became known for to now integrating its software into TVs. And it's ensuring that its own Roku Channel is growing its content heft.

    What drives Roku's relentless innovation is founder/CEO Anthony Wood's experience. In a prior generation, he invented the DVR. Yet his company at the time (ReplayTV) still lost out to TiVo. Beyond the lessons learned, that's a chip on your shoulder that doesn't go away easily.

    Altria and Philip Morris

    Admittedly, these two aren't for everyone. Skip these if you aren't interested in tobacco or cannabis.

    Altria and Philip Morris, which share the Marlboro brand globally, have track records of navigating a declining industry with price hikes and issuing large dividends (Philip Morris currently above 5%, Altria above 8%). That's the high floor.

    Then there are additional possibilities. They were once a single company, and they've flirted with re-merging in the past. Doing so would have logical cost synergies that make a heck of a lot more sense than most mergers since they've already avoided a lot of competitive overlap by geographically splitting their businesses.

    And then there's the potential to transfer their premium tobacco branding to cannabis -- particularly Altria in the U.S.

    Amazon, MercadoLibre, Sea Limited, and Square

    I believe strongly in the megatrends of e-commerce adoption and digital financial disruption. Each of these four has a foot firmly in e-commerce, digital payments, or both in various geographies.

    Who wants to compete against Jeff Bezos and Amazon? If you'd be terrified to compete with them, it makes sense to consider investing in them. Meanwhile, MercadoLibre and Sea Limited are often described as the "Amazon of Latin America" and the "Amazon of Southeast Asia," respectively.

    Drilling in closer reveals that close comparison to be a gross simplification (consider Amazon Web Services and Sea Limited's video games), but the important through line is each is a market leader in e-commerce.

    Square isn't an e-commerce marketplace, but its products and services enable digital commerce and its Cash App is competing well against both PayPal's namesake platform and PayPal's Venmo peer-to-peer payments network.

    Intuitive Surgical

    Robot-assisted surgery beats the shaky hands of humans. That general thesis hasn't changed much from when I first bought Intuitive Surgical stock in 2005.

    Intuitive Surgical is dominant in its space, and it has lots of room to grow as its surgical systems increase in adoption and as the number of its supported procedures increases over time.

    Saying Salesforce has been a serial acquirer is like saying the Cookie Monster has been a baked goods enthusiast. Over the past decade and a half, Salesforce has averaged about four acquisitions a year!

    Normally, I'm not a fan of businesses that rely heavily on buying up other businesses. However, Salesforce's ongoing success in the software as a service (SaaS) market shows it's integrated these add-ons well.

    The company is right to move quickly, too. A key bull case for paying sky-high price-to-sales multiples for so many smaller SaaS companies is that Salesforce can expand and deepen its current offerings. Standing still makes Salesforce's business an easier target. Note that Salesforce trades for “only” 10 times sales.

    With its acquisition of Slack, Salesforce is likely to be slinging more arrows than the competition. I was a shareholder in Slack before the purchase was announced, and a big reason is that I happily use Slack every day to message with my co-workers. It's a very well-designed product. Slack (and its integrations with all kinds of software) allows Salesforce to reach everyone in an organization, not just the sales or tech teams.

    Done right, that's a game changer for Salesforce.

    The House of Mouse is the all-weather tires of a portfolio.

    The pandemic hurt its theme park and movie businesses but helped the Disney+ streaming service. The former will resolve itself, the latter had a "Wow!" first year, and Disney is rightly focusing on growing it.

    Its amazing intellectual property (Marvel/Star Wars/ESPN/Pixar/Disney) makes it the stock I'm probably the most comfortable holding over decades.

    Bitcoin, of course, isn't technically a stock.

    And, frankly, I have no idea where it goes from here. Massive volatility is to be expected.

    But I still think it's worth a look for your portfolio, in small doses. (I allocated 1% when I bought in 2020.)

    It provides asset diversification beyond the stock market, bonds, gold, or real estate. And, while you get currency diversification by buying global stocks, bitcoin gives you one more to fill out the basket.

    At this point, it's by far the largest cryptocurrency, and it's gaining scale and network effects as both disruptive (e.g. Square, PayPal) and traditional (big banks) finance players increase their bitcoin offerings.

    Berkshire Hathaway

    While most of this list is made up of growth-ier stocks, this is the relatively boring value pick of the bunch.

    The Warren Buffett bears will say he's lost his fastball, but that happens every growth cycle. What is true is that it's harder to beat the market as your portfolio size grows. If Berkshire were a mutual fund, it would be the largest actively managed one in the world.

    That said, Berkshire is Buffett's legacy, and he's been stress-proofing it for years to make sure it's in solid shape well after he's no longer running things.

    Showing his faith, he and partner Charlie Munger have been buying back shares at a historic clip. That's a good signal for the rest of us.

    ARK Genomic Revolution ETF

    Cathie Wood and her team have risen to investing world prominence with bold calls (e.g., Tesla) and strong returns.

    For those who aren't well-versed in the genomics space (CRISPR, targeted therapeutics, bioinformatics, molecular diagnostics, stem cells, agricultural biology, etc.), the 0.75% expense ratio is well worth it.

    Whether you pick the stocks yourself or go with this ETF, genomics is an innovative growth industry you'll want exposure to.

    A basket of the Chamath Palihapitiya-sponsored “alphabet” SPACs

    Palihapitiya was an early executive at Facebook who helped it reach scale. Since then, he's been a successful venture capitalist known for his bold straight talk, no matter the subject. Some are turned off by it, but I'm a fan because he has the intelligence to cut straight to the heart of matters.

    While critics question Palihapitiya's incentives and intentions with his SPACs (special purpose acquisition companies), he claims to be tired of making money for wealthy people and wants to enrich regular retail investors in addition to himself.

    Figuring out whether you believe him is key because the most important thing when investing in a SPAC -- which is basically a bunch of cash used to buy into a private company in order to take it public -- is trust in management. Bad or misaligned management is probably the biggest SPAC risk, but there are many.

    As part of a diversified portfolio, the upside in Palihapitiya's ventures is worth their risks.

    And he's planning a lot of them, from IPOA to IPOZ. So far, he's up to six letters of the alphabet.

    • IPOA – Now Virgin Galactic
    • IPOB – Now Opendoor
    • IPOC – Now Clover Health
    • IPOD – Social Capital Hedosophia Holdings Corp. IV: Still a blank check.
    • IPOE – Social Capital Hedosophia Holdings Corp. V: Bringing SoFi public (announced Jan. 7, 2021.)
    • IPOF – Social Capital Hedosophia Holdings Corp. VI: Still a blank check.

    Final takeaways for using this stock list

    If you're starting on your investing journey (or if you want a sanity check), please read through our How to Invest in Stocks guide. It walks through all the basics, from how to get started to how to determine your personal investing strategy to how much of your money to invest in stocks.

    While I'm bullish on each of these stocks and have given you a little info on each, use this list or if you're just getting started, you'll want to see the 15 best stocks for beginners.

    Start with the stocks that speak to you, and feel free to ignore the ones that don't.

    Watch the video: This is Why Im NOT Gardening with WOOD CHIPS this Year (January 2022).