Information

What spider is that in south of Brazil?


I'd like to know if it is possible to identify the spider in the photo below.

In fact, as shown in the next picture, it is very small.

Location: South of Brazil.


9 of the World’s Deadliest Spiders

More than 43,000 different species of spiders are found in the world. Of these, only a small number are said to be dangerous, and less than 30 (less than one-tenth of one percent) have been responsible for human deaths. Why are so few spiders harmful to humans? Much of the reason may result from the size differences between people and spiders. Spider venom is designed to work on smaller animals, but the venom of some species can produce skin lesions in people or produce allergic reactions that result in fatalities. It is important to understand, however, that “death by spider bite” is very rare since clinics, poison control centers, and hospitals often have various species-specific antivenin (the antitoxin) on hand to treat the bite.


Spiders associated with Psychotria carthagenensis Jacquin. (Rubiaceae): vegetative branches versus inflorescences, and the influence of Crematogaster sp. (Hymenoptera, Formicidae), in South-Pantanal, Brazil/Aranhas associadas a Psychotria carthagenensis Jacq. (Rubiaceae): ramos vegetativos versus inflorescencias, e a influencia de Crematogaster sp. (Hymenoptera, Formicidae), no Pantanal Sul, Brasil.

Spiders are scattered over almost all terrestrial environments, being more abundant in areas of rich vegetation (Foelix, 1996). In a micro-scale, the structural complexity of the plant is considered one of the main variables in determining abundance, body size distribution and formation of distinct spider guilds (Souza, 2007). The significance of habitat structure in spider biology has been a topic of numerous ecological studies (Halaj et al., 1998), applying to several spider species in different kinds of plants in different regions (e.g. Gunnarson, 1990 Halaj et al., 1998 2000 Ysnel and Canard, 2000 Souza and Modena, 2004 Souza and Martins, 2004 2005 Romero and Vasconcellos-Neto, 2005).

Branches with inflorescences are structurally distinct from vegetative branches, and may represent microhabitats with different attractions to spiders (Souza, 2007). Inflorescences are frequently highly structured habitats with high density of potential prey (e.g. herbivores and pollinators) (Nentwig, 1993). In addition, the presence of inflorescences adds another dimension to plant architecture because of the change in the microclimatic conditions and availability of refuge against predators (Souza and Modena, 2004).

Psychotria carthagenensis Jacq. (Rubiaceae) is a sub-canopy shrub occurring at Pantanal in flooding vegetation areas, "cambarazal", "capao de vazante", sand or clay soils (Pott and Pott, 1994). This species presents small white flowers with tubular corolla, gathered in cymose terminal inflorescences has diurnal antese and is commonly pollinated by bees and butterflies, and nectar is the main resource offered (Consolaro, 2004). In this study the presence of ants of the genus Crematogaster was observed in several parts of the plant. Other studies have reported a significant presence of ants in other Psychotria species (e.g. Nentwig, 1993 Altshuler, 1999). When ants are present in plants, their predatory and pugnacious behavior towards other animals deter their access to several structures of vegetal organisms (Altshuler, 1999), which can affect principally the arthropod community structure, including the spiders (Mody and Linsenmair, 2004). The goal of this paper was to analyze: i) the spider community in vegetative and reproductive branches of P. carthagenensis concerning relative abundance, guild composition and body size distribution, ii) ant abundance in different types of branches, and iii) the spider behavior when put in contact with inflorescences covered with ants.

This study was carried out from 1st to 4th of October 2005, in two fragments of forest gallery located in the vicinity of "Base de Estudos do Pantanal (BEP)", "Pantanal do Miranda", Central Brazil (19[degrees] 34' S and 57[degrees] 00' W). Thirty plants were surveyed in total 60 branches, two per plant. In each plant, one collector sampled a flowered branch and the other a vegetative branch, both using plastic bags measuring 0.60 x 0.40 m. The branches were approximately 0.40 m long and were 1.50 m above ground. The bagged branches were cut with pruning scissors and packed in bags sealed with adhesive tape. The sample inside the plastic bags was stored in a freezer (-5 [degrees]C) for 12 hours before examination in the laboratory. Each spider was measured (length chelicerae-fianders in millimeters) and stored in alcohol at 70%. The spider species were then identified by specialists. The spiders were classified in guilds according to Uetz et al. (1999). The relative abundance of ants among vegetative and reproductive branches was estimated using similar methods to those which were previously carried out with the spiders. From flowered branches, only the inflorescence was collected, and from vegetative branches, the extremity was collected (about 10 cm).

There were two treatments to verify agonistic interactions between spiders and ants: inflorescences with ants and inflorescences without ants. Each treatment was carried out by placing one spider per inflorescence and its behavior in relation to ants was observed. The spider that stayed on the branch up to five minutes was considered "established" and the spider that escaped before five minutes was considered "non-established". Ten repetitions were made. All spiders used in the experiment were collected with the entomological beater method with aid of a puca all spiders belonged to the Pisauridae family and were approximately 3 mm long. This family was chosen because these spiders were more common in samples for comparison between vegetative and reproductive branches.

The relative abundance of ants and spiders between treatments was compared using Student t-test (SYSTAT 10 software). The guild composition was analyzed using the Morisita-Horm (BIO-DAP software) quantitative index of similarity, whose values vary from 0 to 1, in order to compare guild composition between microhabitats. The distribution of sizes between these two types of branches was compared by Confidence Intervals at 95% analysis. Specimens of spiders were deposited at the "Instituto Butanta--Laboratorio de Artropodes", and ants at the "Colecao de Referencia Zoologica da Universidade Federal do Mato Grosso do Sul".

The total amount of spiders collected was 71, 30 from reproductive and 41 from vegetative branches. There was no difference in the comparison between the average values of spider number in vegetative (Mean = 1.41 SD = 1.268) and reproductive (Mean = 1 SD = 1.462) branches of P. carthagenensis (t = -1.076 df = 28 p = 0.291). One spider of vegetative branch and five ones of reproductive could not be identified. The presence of inflorescence in P. carthagenensis had no significant effect on spider abundance. Even the presence of flowers with different size structures and designs, when compared with vegetative branches, was not sufficient for spiders to be more abundant in flowering branches. Romero and Vasconcellos-Neto (2005), using artificial inflorescences in Bromelia balansae Mez, found a spider colonization rate slower than that without inflorescences. In the case of Bromelia balansae, the presence of the inflorescence provokes a change in the arrangement of the rosettes which consequently interferes in the availability of potential prey that fall in the bromeliad. The results of the present paper seem to contrast with those obtained by Souza and Martins (2004), which found that the number of spiders both in natural and artificial inflorescences was greater than in vegetative branches. In this study, the presence of inflorescence represented an increase in the ant density, and the low density of ants in vegetative branches can explain the reason of more spiders on these branches.

Spiders of the families Theridiidae, Pisauridae, Araneidae and Anyphaenidae were identified up to the possible taxonomic level. All members of Dictynidae are of the genus Dictyna. Mimetidae are two genera, Ero sp. and Gelanor sp., and the others were not identified. Salticidae are Cilystella sp. and Cotinusa sp., and the others not identified. In the reproductive branches the most frequent families were Pisauridae (68%), followed by Salticidae, Mimetidae and Anyphaenidae (8% each), and the least frequent were Dyctinidae and Theridiidae (2% each) Araneidae was absent. In vegetative branches the Pisauridae was also predominant (72%), followed by Salticidae (15%), Anyphaenidae (7.5%), Mimetidae and Araneidae (2.5% each) Theridiidae and Dyctinidae were absent. According to Morisita-Horm index, guild composition in the different types of branches was similar (0,995), which indicates high similarity between habitats. Web-building guild was the least frequent in both branches, and ambushers were the most frequent in both treatments, followed by stalkers and foliage runners (Figure 1). Body size distribution of the two branch types did not differ. In vegetative branches the smallest body size value found was 1 mm and the greatest, 5.5 mm 50% of the spiders in this treatment measured between 2.5 mm and 4.0 mm. In reproductive branches the smallest body size was 1.5 mm and the greatest, 5.0 mm 50% of the spiders in this treatment measured between 2.0 mm and 3.5 mm. The body size distributions show overlap in confidence intervals at 95%: vegetative = 3.44-2.71 mm and reproductive = 3.41-2.66 mm. The presence of inflorescence did not represent a distinct guild composition and body size distribution. The high frequency of ambushers was expected in flowering branches, because spiders from this guild belong to the Thomisidae family, typical of inflorescences (Nentwig, 1993 Souza and Modena, 2004 Souza and Martins, 2004 Souza, in press). This result may be the best indicator that some factor is interfering in the spider community.

Of 193 ants sampled, 138 were from flowered branches (Mean = 4.6 SD = 6.447) and 55 from vegetative branches (Mean = 1.833 SD = 3.119). The average relative abundance of ants differed significantly when compared between treatments (t = 2.517 df = 29 p = 0.018). In the experiment carried out to verify the spiders' behavior towards ants, 100% (n = 10) of the spiders remained in the inflorescences in control treatment. In the treatment of inflorescences with ants, 90% (n = 9) of the spiders were expelled and only 10% (n = 1) remained in the inflorescence. This spider in particular was particularly trapped in the inflorescence in a region above which the ants had been circulating.

Since the inflorescences were densely occupied by ants, we suggest that ants, which affected Pisauridae in our experiment, may be influencing the distribution of all members of the spider community. According to Mody and Linsenmair (2004) and Izzo and Vasconcelos (2005), ants clearly reduce the arthropod density, like herbivores and important predators such as spiders. Halaj et al. (1997) also found a strong interaction between spiders and ants, with spider displacement by ants. The reduction of spiders by the ants represents a contrast with other studies, which show a null or a positive correlation between spider and ant numbers (Grant and Moran, 1986 Karhu, 1998). In the case of P. carthagenensis, there is an indication of a negative effect, because ants may displace both the spiders and their potential prey. The ant density in different parts of the plant may explain better the distribution of the spiders and their potential prey.

Acknowledgements--We convey our thanks to the teachers E.A. Fisher and G. Graciolli for their suggestions F.A.M. Santos for the help in the analysis A.L.T. Souza for the comments and the bibliography G.R. Giraldelli for the help in field A.D. Brescovit for spider identification I. Leal and C.R.F. Brandao for their help with Crematogaster D. Rossi and Prof. R. Vieira for text revision to the organizers and participants of the Field Ecology Course "Ecologia do Pantanal--2005" for logistic support and discussions and to the anonymous referees for their valuable comments on the manuscript. The first author had a fellowship from Conservation International-Brazil and the second from CAPES.

Received February 20, 2006--Accepted September 13, 2006--Distributed May 31, 2008 (With 1 figure)

ALTSHULER, DL., 1999. Novel interactions of non-pollinating ants with pollinators and fruit consumers in a tropical forest. Oecologia, vol. 119, no. 4, p. 600-606.

BIODAP software. Diversity Ecological and Its Measurements. Fundy National Park and Parks Canada (PHQ). (http://nhsbig. inhs.uiuc.edu accessed in 20/04/2005).

CONSOLARO, HN., 2004. Biologia reprodutiva de duas especies de Rubiaceae em matas de galeria do Triangulo Mineiro-MG. (Dissertacao de Mestrado)--UFU, Uberlandia-MG. 58 p.

FOELIX, RF., 1996. Biology of spiders. Oxford: Oxford University Press. 2 ed. 330 p.

GRANT, S. and MORAN, VC., 1986. The effects of foraging ants on arboreal insect herbivores in an undisturbed woodland savanna. Ecological Entomology, vol. 11, no. 1, p. 83-93.

GUNNARSSON, B., 1990. Vegetation structure and the abundance and size distribution of spruce-living spiders. Journal of Animal Ecology, vol. 59, no. 2, p. 743-752.

HALAJ, J., ROSS, DW. and MOLDENKE, AR., 1997. Negative effects of ant foraging on spiders in Douglas-fir canopies. Oecologia, vol. 109, no. 2, p. 313-322.

-, 1998. Habitat structure and prey availability as redictors of the abundance and community organization of spiders in western Oregon forest canopies. The Journal of Arachnology, vol. 26, no. 2, p. 203-20.

IZZO, TJ. and VASCONCELOS, HL., 2005. Ants and plant size shape the structure of the arthropod community of Hirtella myrmecophila, an Amazonian ant-plant. Ecological Entomology, vol. 30, no. 6, p. 650-656.

KARHU, KJ., 1998. Effects of ant exclusion during outbreaks of a defoliator and a sap-sucker on birch. Ecological Entomology, vol. 23, no. 2, p. 185-194.

MODY, K. and LINSENMAIR, KE., 2004. Plant-attracted ants affect arthropod community structure but not necessarily herbivory. Ecological Entomology, vol. 29, no. 2, p. 217-225.

NENTWIG, W., 1993. Spiders of Panama. Biogeography, investigation, phenology, check list, key and bibliography of a tropical spider fauna. Fauna and Flora Handbook no. 12. Gainesville, USA: Sandhill Crane Press. 247p.

POTT, A. and POTT, VJ., 1994. Plantas do Pantanal. 1a ed. Mato Grosso do Sul: Embrapa, Corumba. 320p.

ROMERO, GQ., and VASCONCELLOS-NETO, J., 2005. The effects of plant structure on the spatial and microspatial distribution of a bromeliad-living jumping spider (Salticidae). Journal of Animal Ecology, vol. 74, no. 1, p. 12-21.

SOUZA, ALT., 2007. Influencia da estrutura do habitat na distribuicao de aranhas. In GONZAGA, MO., JAPAYASSU, HF. and SANTOS, AJ. (eds). Ecologia e Comportamento de aranhas, ed. Interciencia. Rio de Janeiro, 400 p.

SOUZA, ALT. and MARTINS, RP., 2004. Distribution of plant-dwelling spiders: inflorescences versus vegetative branches. Austral Ecology, vol. 29, no. 6, p. 342-349.

--, 2005. Foliage density of branches and distribution of plant-dwelling spiders. Biotropica, vol. 37, no. 3, p. 416-420.

SOUZA, ALT. and MODENA, ES., 2004. Distribution of spiders on different types of inflorescences in the Brazilian Pantanal. The Journal of Arachnology, vol. 32, no. 2, p. 345-348.

SYSTAT software. Version 10, 2000. SPSS Inc.

UETZ, GW., HALAJ, J. and CADY AB., 1999. Guild structure of spiders in major crops. The Journal of Arachnology, vol. 27, no. 1, p. 270-280.

YSNEL, F. and CANARD, A., 2000. Spider biodiversity in connection with the vegetation structure and the foliage orientation of hedges. The Journal of Arachnology, vol. 28, p. 107-114.

Programa de Pos-Graduacao em Ecologia e Conservacao, Universidade Federal do Mato Grosso do Sul--UFMS, CP 549, CEP 79070-900, Campo Grande, MS, Brazil


Spider monkey

Our editors will review what you’ve submitted and determine whether to revise the article.

Spider monkey, (genus Ateles), large, extremely agile monkey that lives in forests from southern Mexico through Central and South America to Brazil. In spite of its thumbless hands, this lanky potbellied primate can move swiftly through the trees, using its long tail as a fifth limb. The seven species of true spider monkeys are classified in the genus Ateles. The woolly spider monkey, or muriqui, which is a close relative but not a true spider monkey, is placed in the genus Brachyteles.

Spider monkeys weigh about 6 kg (13.2 pounds) and are 35–66 cm (14–26 inches) long, excluding the heavily furred tail, which is longer than the body. The coat, of variable length and fineness, ranges among the several species from gray to reddish, dark brown, or black. Most have a black face with white eye rings, but some have a flesh-coloured face.

The monkeys live in bands numbering up to 35 animals but forage in smaller groups, roaming the highest branches during the day. They feed most intensively early in the day, relishing fruit supplemented by nuts, seeds, buds, flowers, and leaves as well as spiders and bird eggs. They do not normally descend from the trees. They will leap or drop spread-eagled from one tree to another. Spider monkeys are dextrous with their tail as well as their hands. They pick up objects with the tail, and they hang from branches by using the tail alone.

Spider monkeys that are shot with arrows while being hunted for food sometimes remove the arrows with their hands and attempt to stem the bleeding. Wary of humans, they will break off tree branches and try to drop them on intruders, and they bark like terriers when approached. Spider monkeys also produce a variety of other sounds. When separated from other members of their group, they call to one another in a whinnying voice like a horse. They are also capable of prolonged screams.

Single young are born in seclusion after a gestation period of about 139 days and are dependent on the mother for a year. Time between births ranges from two to five years.

According to the International Union for Conservation of Nature (IUCN) Red List of Threatened Species, all true spider monkey species are threatened. Most are endangered, and two of these—the brown-headed spider monkey (A. fusciceps), which is found from eastern Panama through northwestern Ecuador, and the variegated, or brown, spider monkey (A. hybridus), which inhabits northeastern Colombia and northwestern Venezuela—are listed as critically endangered. Spider monkeys are widely hunted for food by local people. Consequently, some of their population decline has been attributed to hunting pressure. However, habitat loss resulting from logging and land clearing is also thought to play a significant role. Spider monkeys are susceptible to malaria and are used in laboratory studies of the disease.


Nine Colorful Species of Tarantulas Found in Brazil

Tree-dwelling (arboreal) tarantulas are known from a few tropical places in Asia, Africa, South and Central America and the Caribbean. They have a lighter build, thinner bodies and longer legs, better suited for their habitat. Their core area is the Amazon, from where most of the species are known and normally very common, living in the jungle or even in house’s surroundings.

Now, nine species were described from Central and Eastern Brazil, including four of the smallest arboreal species ever recorded.

From upper left to lower right, respectively: female Typhochlaena amma, female Typhochlaena costae, female Typhochlaena paschoali, female Pachistopelma bromelicola (Rogerio Bertani / CC-BY 3.0)

A study, published in the journal ZooKeys, describes nine new tarantulas named: Typhochlaena amma, T. costae, T. curumim, T. paschoali, Iridopelma vanini, I. katiae, I. marcoi, I. oliveirai and Pachistopelma bromelicola.

“Instead of the seven species formerly known in the region, we now have sixteen,” Dr Bertani said. “In a resurrected genus with a mysterious single species known from 1841, we have now five species. These are the smallest arboreal tarantulas in the world, and their analysis suggests the genus to be very old, so they can be considered relicts of a formerly more widely distributed taxon”.

Female Iridopelma vanini, left, and Iridopelma katiae (Rogerio Bertani / CC-BY 3.0)

“The discovery of all these new species outside the Amazon was unexpected and illustrates how little we know of the fauna surrounding us, even from hot spots of threatened biodiversity like the Brazilian Atlantic Rainforest and the Cerrado, a kind of savannah vegetation.”

Immature Iridopelma oliveirai in progression, left, and Iridopelma marcoi (Rogerio Bertani / CC-BY 3.0)

“These species are highly endemic and the regions where they live are suffering high pressure from human activities. Therefore, studies for their conservation are necessaries. Furthermore, all these new species are colorful, which could attract the interest for capturing them for the pet trade, constituting another threat.”

Bibliographic information: Bertrani R. 2012. Revision, cladistic analysis and biogeography of Typhochlaena C. L. Koch, 1850, Pachistopelma Pocock, 1901 and Iridopelma Pocock, 1901 (Araneae, Theraphosidae, Aviculariinae). ZooKeys 230: 1-94 doi: 10.3897/zookeys.230.3500


How do accidents with the spider spider occur?

Human accidents occur in the home. Weavers often hide in shoes, behind curtains and in the middle of clothes. In these places, they end up attacking the man, who is surprised by the presence of the spider.

Rural workers are also subject to attack by the spider spider, especially when collecting bunches of bananas. When collecting bunches of bananas and carrying them on their backs, they may suffer from the bite of the spider spider.

In Brazil, there are several cases of accidents with the spider spider. Most are concentrated in the South and Southeast regions.

The brown spider and the crab spider are also responsible for causing accidents in Brazil.


Contents

Argiope bruennichi is commonly known as the wasp spider. In Australia, Argiope keyserlingi and Argiope aetherea are known as St Andrew's cross spiders, for their habit of resting in the web with paired legs outstretched in the shape of an X and mirroring the large white web decoration (the cross of St. Andrew [3] having the same form). This white zigzag in the centre of its web is called the stabilimentum or web decoration. [3]

In North America, Argiope aurantia is commonly known as the black and yellow garden spider, zipper spider, corn spider, or writing spider, because of the similarity of the web stabilimenta to writing.

The East Asian species Argiope amoena is known in Japan as kogane-gumo. In the Philippines, they are known as gagambang ekis ("X spider"), and gagambang pari ("priest spider", due to the spider's body resembling a priest's head with a mitre).

The average orb web is practically invisible, and it is easy to blunder into one and end up covered with a sticky web. The visible pattern of banded silk made by Argiope is pure white, and some species make an "X" form, or a zigzag type of web (often with a hollow centre). The spider then aligns one pair of its legs with each of the four lines in the hollow "X", making a complete "X" of white lines with a very eye-catching spider forming its centre.

The zigzag patterns, called stabilimenta, reflect UV light. [3] They have been shown to play a role in attracting prey to the web, and possibly in preventing its destruction by large animals. The centres of their large webs are often just under 1 metre above the ground, so they are too low for anything much larger than a rabbit to walk under. The overtness of the spider and its web thus has been speculated to prevent larger creatures from accidentally destroying the web and possibly crushing the spider underfoot.

Other studies suggest that the stabilimenta may actually lead predators to the spider species such as A. keyserlingi place their web predominantly in closed, complex habitats such as among sedges.

As Argiope sit in the centre of their web during the day, they have developed several responses to predators, such as dropping off the web, retreating to the periphery of the web, or even rapidly pumping the web in bursts of up to 30 seconds, similar to the motion done by the unrelated Pholcus phalangioides. [4]

Writing spider on stabilimentum in Iowa

Argiope spp. spider Found in Goose Creek, South Carolina in October of 2019.

The male spider is much smaller than the female, [5] and unassumingly marked. When it is time to mate, the male spins a companion web alongside the female's. After mating, the female lays her eggs, placing her egg sac into the web. The sac contains between 400 and 1400 eggs.

These eggs hatch in autumn, but the spiderlings overwinter in the sac and emerge during the spring. The egg sac is composed of multiple layers of silk and protects its contents from damage however, many species of insects have been observed to parasitise the egg sacs.

Like almost all other spiders, Argiope are harmless to humans. As is the case with most garden spiders, they eat insects, and they are capable of consuming prey up to twice their size. A. savigny was even reported to occasionally feed on the small bat Rhynchonycteris naso. [6]

They can potentially bite if grabbed, but other than for defense, they do not attack large animals. Their venom is not regarded as a serious medical problem for humans it often contains a wide variety of polyamine toxins with potential as therapeutic medicinal agents. [7] Notable among these is the argiotoxin ArgTX-636 (A. lobata).

A bite by the black and yellow garden spider (Argiope aurantia) is comparable to a bee sting, with redness and swelling. For a healthy adult, a bite is not considered an issue. [8] [9] [10]

Though they are not aggressive spiders, the very young, elderly, those with compromised immune systems, or those with known venom allergies should exercise caution, just as one would around a beehive. [8]

The first description of the genus Argiope is attributed to Jean Victoire Audouin in 1826, [1] although he wrote that the genus was established by Savigny. [11] In the first edition of the work in which the description appeared (Description de l'Égypte: Histoire Naturelle), Audouin used the spelling "Argyope", for both the French vernacular name and the Latin generic name. [11] In the second edition, he continued to use "Argyope" for the French vernacular name, but the first mention of the Latin generic name had the spelling "Argiope", although the binomial names of the species continued to use "Argyope". [12] This led to controversy as to whether Audouin had intended to correct the spelling of the generic name, which is derived from the Greek αργιόπη. In 1975, the International Commission on Zoological Nomenclature validated the spelling "Argiope", on the basis that the change from the first to the second edition was an intended correction. [13] [14]

Species Edit

As of April 2019 [update] , Argiope contains 88 species: [2]

  • A. abramoviLogunov & Jäger, 2015 – Vietnam
  • A. aemula(Walckenaer, 1841) – India to Philippines, Indonesia (Sulawesi), Vanuatu
  • A. aetherea(Walckenaer, 1841) – China to Australia
  • A. aetheroidesYin, Wang, Zhang, Peng & Chen, 1989 – China, Japan
  • A. ahngeriSpassky, 1932 – Iran, Kyrgyzstan, Turkmenistan, Uzbekistan, Tajikistan?
  • A. amoenaL. Koch, 1878 – China, Korea, Taiwan, Japan
  • A. anasujaThorell, 1887 – Seychelles to India, Pakistan, Maldives
  • A. anomalopalpisBjørn, 1997 – Congo, South Africa
  • A. appensa(Walckenaer, 1841) – Hawaii, Taiwan to New Guinea
  • A. argentata(Fabricius, 1775) – USA to Chile, Argentina
  • A. aurantiaLucas, 1833 – Canada to Costa Rica
  • A. aurocinctaPocock, 1898 – Central, East, Southern Africa
  • A. australis(Walckenaer, 1805) – Central, East, Southern Africa, Cape Verde Is.
  • A. bivittigeraStrand, 1911 – Indonesia
  • A. blandaO. Pickard-Cambridge, 1898 – USA to Costa Rica
  • A. boesenbergiLevi, 1983 – China, Korea, Japan
  • A. bougainvilla(Walckenaer, 1847) – New Guinea to Solomon Is.
  • A. bruennichi(Scopoli, 1772) – Europe, Turkey, Israel, Russia (Europe to Far East), Iran, Central Asia to China, Korea, Japan
  • A. brunnescentiaStrand, 1911 – New Guinea, Papua New Guinea (Bismarck Arch.)
  • A. buehleriSchenkel, 1944 – Timor
  • A. bullockiRainbow, 1908 – Australia (New South Wales)
  • A. butchkoLeQuier & Agnarsson, 2016 – Cuba
  • A. caesareaThorell, 1897 – India, Myanmar, China
  • A. caledoniaLevi, 1983 – New Caledonia, Vanuatu
  • A. cameloidesZhu & Song, 1994 – China
  • A. carvalhoi(Mello-Leitão, 1944) – Brazil
  • A. catenulata(Doleschall, 1859) – India to Philippines, New Guinea, Australia
  • A. chloreisThorell, 1877 – Laos, Indonesia, Papua New Guinea
  • A. comoricaBjørn, 1997 – Comoros, Mayotte
  • A. coquereli(Vinson, 1863) – Tanzania (Zanzibar), Madagascar
  • A. dangJäger & Praxaysombath, 2009 – Thailand, Laos
  • A. dietrichaeLevi, 1983 – Australia (Western Australia, Northern Australia)
  • A. doboensisStrand, 1911 – Indonesia, New Guinea
  • A. doleschalliThorell, 1873 – Indonesia
  • A. ericaeLevi, 2004 – Brazil, Argentina
  • A. flavipalpis(Lucas, 1858) – Africa, Yemen
  • A. floridaChamberlin & Ivie, 1944 – USA
  • A. halmaherensisStrand, 1907 – Indonesia (Moluccas) to New Guinea
  • A. hinderlichiJäger, 2012 – Laos
  • A. hoiseniTan, 2018 – Malaysia (Peninsula)
  • A. intricataSimon, 1877 – Philippines
  • A. jinghongensisYin, Peng & Wang, 1994 – China, Vietnam, Laos, Thailand
  • A. kaingangCorronca & Rodríguez-Artigas, 2015 – Argentina
  • A. katherinaLevi, 1983 – Northern Australia
  • A. keyserlingiKarsch, 1878 – Australia (Queensland, New South Wales, Lord Howe Is.)
  • A. kochiLevi, 1983 – Australia (Queensland)
  • A. legionisMotta & Levi, 2009 – Brazil
  • A. leviiBjørn, 1997 – South Africa, Kenya, Tanzania
  • A. lobata(Pallas, 1772) – Southern Europe to Central Asia and China, northern Africa, South Africa, Israel, India, from Myanmar to New Caledonia and northern Australia
  • A. luzona(Walckenaer, 1841) – Philippines
  • A. macrochoeraThorell, 1891 – India (Nicobar Is.), China
  • A. madangLevi, 1984 – New Guinea
  • A. magnificaL. Koch, 1871 – Australia (Queensland) to Solomon Is.
  • A. mangalKoh, 1991 – Singapore
  • A. manilaLevi, 1983 – Philippines
  • A. mascordiLevi, 1983 – Australia (Queensland)
  • A. minutaKarsch, 1879 – Bangladesh, East Asia
  • A. modestaThorell, 1881 – Borneo to Australia
  • A. niasensisStrand, 1907 – Indonesia
  • A. oculaFox, 1938 – China, Taiwan, Japan
  • A. ocyaloidesL. Koch, 1871 – Australia (Queensland)
  • A. pentagonaL. Koch, 1871 – Fiji
  • A. perforataSchenkel, 1963 – China
  • A. pictaL. Koch, 1871 – Indonesia (Moluccas) to Australia
  • A. pictulaStrand, 1911 – Indonesia (Sulawesi)
  • A. ponapeLevi, 1983 – Caroline Is.
  • A. possoicaMerian, 1911 – Indonesia (Sulawesi)
  • A. probataRainbow, 1916 – Australia (Queensland)
  • A. protensaL. Koch, 1872 – New Guinea, Australia, New Caledonia, New Zealand
  • A. pulchellaThorell, 1881 – India to China and Indonesia
  • A. pulchelloidesYin, Wang, Zhang, Peng & Chen, 1989 – China
  • A. radonLevi, 1983 – Northern Australia
  • A. ranomafanensisBjørn, 1997 – Madagascar
  • A. reinwardti(Doleschall, 1859) – Malaysia to New Guinea
    • Argiope r. sumatrana(Hasselt, 1882) – Indonesia (Sumatra)
    • Argiope t. deserticolaSimon, 1906 – Sudan
    • Argiope t. kauaiensisSimon, 1900 – Hawaii

    Argiope use autotomy - restricting blood flow to their own leg until it falls off - to minimize blood loss due to injury. [15] [16] This is triggered by pain. [15] [16] Honeybee and wasp venoms induce the same pain in Argiope - even when the injury is minor - causing Argiope to drop the affected leg. [15] [16] The same effect can also be produced by chemically fractionated components of those venoms (specifically serotonin, histamine, and phospholipase A2) that also cause pain in humans. [15] [16]


    Myth: Deadly Australian/Brazilian spiders

    Fact: The previous myth page, where I said that no spider species anywhere can properly be called "deadly," generated more comments than any other on the site. Most were from Australians who were certain their country at least had truly deadly spiders, including the Sydney Funnelweb Spider, Atrax robustus, and the Redback Spider, Latrodectus hasselti. Some also mentioned White-tailed Spiders, genus Lampona. Some comments were from Brazilians who put forward their Phoneutria wandering spiders as the world's deadliest.

    To start with, these people had misunderstood what I said. I never claimed that no human ever died from spider venom. What I said was, there is no species whose bite kills much more than 5% of its victims, nor any spider that kills within minutes, like in the movies. This applies just as strongly to Australia and Brazil as to the USA.

    According to the Australian Museum, the number of human deaths from authentic spider bites of any kind in Australia since 1979 has been zero. A recent published medical study followed 750 genuine Australian spider bite cases with identified spiders over 27 months (1999-2001). Only 44 bites (6%, mostly redback spider bites) had significant effects. Only 6 redback bites and 1 Atrax bite were serious enough to need antivenom. In no case was there any sign of allergic response to spider venom, and I have only seen one such case in North America in 44 years.

    Atrax robustus, the Sydney Funnelweb Spider, is often publicized as the "world's deadliest." Authentic medical information suggests otherwise. There have been no deaths (out of 30-40 bites per year) since antivenom was introduced in 1980. During the 53 year period 1927-1979 there were 13 or 14 known deaths, which would be a death rate of under one percent! Although one child died in 15 minutes, adult fatalities typically took 2-3 days. 90% of Atrax bites are judged not serious enough to need antivenom.

    Most serious spider bites in Australia are from the Redback, Latrodectus hasselti, a close relative of American black widows with very similar venom and effects. The recent study mentioned above tallied 56 genuine redback bites. Only 37 (66%) had any serious effects, and only 6 (11%) were serious enough to need antivenom. There have been no redback-caused human deaths in several decades.

    White-tailed spiders, Lampona cylindrata and relatives, have recently been blamed for Australian cases of severe necrotic lesions, but this connection was not based on enough evidence. The same authors who did the 750-bite study mentioned above, gathered a further 130 cases (aged 3-76 years) bitten by identified Lampona spiders. Local pain and itching were the only effects. No one developed any lesion or ulcer. White-tailed spiders are not guilty of doing any serious harm to humans this page has more details.

    Brazilian Wandering Spiders (aranhas armadeiras), Phoneutria nigriventer, P. keyserlingi and P. fera, are sometimes said to have the world's most toxic spider venom – probably based on a well publicized study where mice were killed by intravenous injection of as little as 0.006 mg of venom. Since I'm a man, not a mouse, that doesn't worry me much. Authoritative sources state that over 7,000 authentic cases of human bites from these spiders have been recorded, with only around 10 known deaths, and about 2% of cases serious enough to need antivenom. So despite the surprisingly large number of bites, this spider is not exactly public enemy number one either.

    Most medical conditions blamed on spiders by physicians lack confirmation that any actual spider was involved in the case. Spider bites of all kinds are rare events (as opposed to other bites and medical conditions that get wrongly blamed on spiders). Although it is possible for a spider bite to cause death, that is a very unlikely outcome and does not happen in enough cases to justify calling any spider "deadly."

    "Everything that 'everybody knows' about spiders is wrong!" —Rod Crawford sets the record straight with Spider Myths.


    Why Thousands of Spiders Are Crawling in the Skies Over Brazil

    To revist this article, visit My Profile, then View saved stories.

    To revist this article, visit My Profile, then View saved stories.

    Last week, spiders descended in droves upon a town in southern Brazil – literally.

    When 20-year-old web designer Erick Reis left a friend's house on Sunday, he saw what looked like thousands of spiders overhead, reported G1, a Brazilian news site, on Feb. 8. The large, sturdy spiders were hanging from power lines and poles, and crawling around on a vast network of silk strands spun over the town of Santo Antonio da Platina.

    Reis did what many of us might do: He pulled out his camera and shot a video of spiders seemingly falling from the sky.

    As creeptastic is it may be, "The phenomenon observed is not really surprising," said Leticia Aviles, who studies social spiders at the University of British Columbia. "Either social or colonial spiders may occur in large aggregations, as the one shown in the video." The reason, she and others say, is simple: This is how they hunt.

    An early report suggested the swarming spiders were Anelosimus eximius, a social species of spider that weaves communal webs, lives together as adults, and shares childcare duties.

    However, it appears that initial assessment may be wrong. The spiders in the video are more likely a species of colonial spider that aggregates individual webs and lives in groups only temporarily, dispersing before reproducing, Aviles said.

    "The spiders I saw in the video are not Anelosimus eximius," said Deborah Smith, an entomologist at the University of Kansas who specializes in social spiders. She notes that A. eximius is a bit smaller than the arachnids Reis filmed, and may not live that far south. "The spiders in the video are very large and robust," she said. "It might be worth looking at Parawixia bistriata, a large, group-living orb weaver, to see if that one fits the bill."

    Arachnologist George Uetz agrees. "This is definitely not Anelosimus eximius," said Uetz, who studies spiders at the University of Cincinnati. He notes that the spiders appear to be spread out on a colonial network of individual orb webs (rather than building a communal nest) and resemble big, orb-weaving spiders – perhaps Parawixia bistriata. "This colony is quite large," he said, noting that the spiders aren't actually raining down. "The web is fixed, although it is very fine and mostly invisible," he said.

    Cornell University arachnologist Linda Rayor and Aviles also agree that what's probably being filmed is a massive P. bistriata colony. That species lives in South American savannas and spins colonial webs. A bit of good news is that their venom is not believed to be harmful to humans, Uetz said.

    If this is Parawixia, or a similar species, there's a reason the spiders may have appeared to come out of nowhere. "At night, they all collect in a colonial retreat, probably out of sight in a tree," Uetz said. "Then they build the colonial framework early in the day, and build individual webs upon it. They sit on these webs and capture prey."

    Whether the spiders are setting up camp or dispersing is an open question. It's possible that Reis caught the conglomerate just as they had moved in to a new home – in which case he'll see spiders in the sky whenever he visits his friends. At least for as long as insects are plentiful and the neighborhood is safe from birds, or until it's time to reproduce. P. bistriata colonies dissolve before the spiders make more spiders, Aviles said. When they are clumped together, the groups tend to comprise single families.

    "I suppose those can be quite large," Aviles said. "Or, in some cases, multiple families may remain aggregated, giving rise to a colony as huge as the one shown in the video."

    It's also possible the spiders were caught in the act of dispersing, and that the massive web overhead is temporary, though that's more likely if the spiders are, in fact, Anelosimus eximius. An easy to make a determine which species they are is to look for the presence of an orb web, which would point toward Parawixia, Aviles said. Or better yet, snap a close-up photo of one of the spiders. Any volunteers?


    It's Raining Spiders in Brazil

    In case you don&rsquot have enough nightmare fuel, try moving to the Brazilian town of Espírito Santo do Dourado. There, residents have reported that the sky is regularly filled with spiders, which rain down on unsuspecting people like some kind of demon weather.

    A video of the phenomenon was captured by 14-year-old João Pedro Martinelli Fonseca, who was visiting his grandparents in the town located in the southern state of Minas Gerais, just north of Rio de Janeiro. There, apparently it&rsquos common to see a sky full of small, black dots as spiders fall from the sky. Take a look:

    This sort of behavior is reportedly common for this particular species of orb-weaving spider native to the southern half of South America. On humid nights, these spiders work together to weave giant webs spanning dozens of feet and reaching from tree to tree. In this video, the spiders aren&rsquot really falling from the sky so much as hanging out there, waiting for prey.


    Watch the video: Natur EXTREM: Das sind die größten Tiere der Welt. Galileo. ProSieben (December 2021).