Gaius villosus

Gaius villosus
	Gaius villosus (museum specimen)
Systematics
Superfamily :	Idiopoidea
Family :	Idiopidae
Subfamily :	Arbanitinae
Tribe :	Aganippini
Genre :	Gaius
Type :	Gaius villosus
Scientific name of the genus
	Gaius
	Rainbow , 1914
Scientific name of the species
	Gaius villosus
	Rainbow , 1914

Gaius villosus is a spider from the suborder tarantula that is widespreadin the Western Australian wheat belt . Their monotypical genus Gaius belongs to the family Idiopidae . A synonym of Gaius villosus used until 2017is Anidiops villosus , the other species of Anidiops are now in the genus Idiosoma .

Gaius villosus is considered to be one of the largest and best adapted to semi-arid habitats among the spiders in Australia collectively referred to as "trapdoor spiders". In contrast to many of its relatives, the species has a large distribution area and is common in places.

description

Genus Gaius

Gaius villosus , ocellen field of an adult female, rear ocelles above, drawing from the first description

The species of the genus Gaius differ from all other genera of the family Idiopidae by the combination of the following characteristics:

the trapezoidal arrangement of the anterior ocelles , the posterior lateral ocelles stand in front of the middle and form a pronounced arch with them;
a pronounced distal tibial spur on the pedipalps of male spiders;
the thick hair on the body and legs.

Most of the species in the genus Gaius , some of which have not been described in collections, have an additional massive tibial spur. They reach a considerable size and, apart from the species of the Theraphosidae family , are among the largest Australian tarantulas .

Since there are no sufficient morphological characteristics for the determination of genus and species for adult female and for juvenile specimens , a molecular biological examination is used today for the determination .

Gaius is closely related to the genus Eucyrtops Pocock , 1897. Gaius differs from this genus in its size, the thicker hair on the body and legs and the distal tibial spur.

Gaius villosus

With a body length of up to five centimeters , including the chelicerae , Gaius villosus is one of the largest Australian spiders from the trapdoor spider relatives. Their size is understood as an evolutionary adaptation to their semi-arid habitats, as it means a reduction in the relative body surface area and water loss.

The species is characterized by its very strong hair, its color is dark brown, almost black. Due to its size, its strong legs and pedipalps as well as the massive chelicerae it is easy to identify as a tarantula. In the field, the species can be recognized by the characteristic features of its living tubes.

distribution

Avon Wheatbelt Bioregion in Western Australia

The type locality of Gaius villosus is the Minnivale Nature Reserve in the Shire of Dowerin, Western Australia . The type locality is in the bioregion Avon Wheatbelt , in turn, in the WWF regarded as endangered WWF ecoregion South West Australia Savannas is.

The distribution area of the genus Gaius extends in Western Australia from the southern wheat belt and the western Nullarbor Plain to the north to Pilbara and the Small Sand Desert . There is a semi-arid climate with dry summers and winter rainfall. The habitats of Gaius villosus are often characterized by mulga or thickets of other types of acacia and belong to a type of landscape known in Australia as Wodjil . However, the species also occurs in habitats in which the casuarina family or eucalyptus dominate. Gaius villosus prefers loamy soils.

Way of life

Residential tubes

The species of the genus Gaius live as ambulance hunters in up to 70 centimeters deep vertical living tubes in the area of the litter layer under trees or bushes, where there is always sufficient humidity and moderate temperatures. The living tubes are closed with a hinged lid made of spider silk and small twigs and camouflaged with chunks of earth spun in. The living tube is always lined with spider silk up to a few centimeters below the entrance opening . The upper area of this lining is only loosely attached to the wall of the residential tube with a few threads. After eating, the spiders often detach the casing from the wall, spend indigestible food residues in the space between them, and fasten the casing again. In the event of danger from an intruder, the spider loosens the "stocking" at the top from the wall and pulls it down, so that from above the image of an empty tube on the ground covered with food remains appears.

The spiders create a fan of twigs around the entrance of the residential tube with the entrance in the center. The branches are attached to the edge of the living tube with spider threads and primarily have a function as signal transmitters, whose contact with potential prey is perceived by the spiders with the tarsi . The lurking spider leaves its living tube a few centimeters when it sees prey. The branches thus enlarge the hunting area in comparison to other trapdoor spiders, which only grab prey that can be overpowered without leaving the tunnel. The ring-shaped arrangement of stones around the entrance of the living tubes of a Namibian species of the genus Ariadna ( fishing web spiders ) serves the same purpose. It increases the area of perception and is considered a form of tool use. In addition, dew and raindrops collect on the branches, which improve the spider's water supply.

Gaius villosus is dependent on an intact litter layer with appropriate building material and on the shade of the vegetation. Disruptions such as the removal of twigs or even the cover of the living tube by rummaging birds and other animals can be tolerated by adult spiders if the living tube itself remains undamaged. In these cases, the branch made of branches is rearranged and the lid is replaced, sometimes the wrong way round. Young spiders can dig a new tube if the old one is destroyed. When it is first buried, the young spider only digs deep enough to completely retreat into the tube. Then the fan is made of twigs and finally the trap door is built. The order is changed in later buildings, the trapdoor is then placed in front of the fan. This is attributed to the need to get food quickly, which is a priority for young spiders who have just emerged from the mother's tube. After the first ingestion of food, the safety aspect of a trap door comes to the fore.

As they grow up, the trapdoor spider's living tubes are repeatedly expanded in diameter and depth. In other species, this happens during autumn rains, when the soil is moist and can be worked. The loosened earth is thrown out by the spiders without leaving the living tube, so that it forms a ring around the entrance. Gaius villosus is one of the few species that expand their living tubes after summer thunderstorms. Since throwing the earth out of the branches would impair the function of the fan, the species has developed its own strategy for disposing of the earth. Just below the “hinge” of the trap door, she digs a tunnel sideways, the ceiling of which she forms with the excavated earth. Seen from the outside, this tunnel looks like a bulge of earth leading away from the residential tube. In this way, the spider remains largely hidden from predators when it is disposed of, and birds only try to capture the spider in the tunnel in rare cases. After widening the living tube, the spider closes the tunnel entrance with earth and covers it again with spider silk. The unused tunnel collapses the next time it rains.

The diameter of the lids is an indication of the age of the spider that lives in a living tube. It takes five years for Gaius villosus to grow into an adult specimen, and sexual maturity occurs at the age of six. Lid diameters of four and more centimeters and tube diameters of more than 3.5 centimeters indicate a sexually mature female. With lid diameters of around five centimeters, which can decrease to 4.5 centimeters during the summer, there is no further increase. The actual age of a spider can later be verified with the help of the recordings via a marked residential tube, since the female spiders always remain in their residential tube and the residential tubes are not re-occupied after the death of a resident.

Aggregations

Due to the low mobility of the young spiders, Gaius villosus forms aggregations with numerous living tubes of spiders of different ages. The living tubes of the young spiders are usually located under the same tree or shrub as that of their mother, which means that there can be dozens of living tubes under a single tree. Assuming a sufficient number of prey animals, the density can be so great that the compartments made of branches around the entrances of the living tubes almost collide. Such densely populated areas or aggregations are separated from one another by areas without a litter layer or unsuitable soil for other reasons. Depending on the age of the tree or shrub under which a mother's nest lies, the litter layer can be so dense that young spiders cannot dig a burrow there. In these cases they wander around until they find a suitable place and are increasingly threatened by predators. The actually disruptive activity of rummaging birds and small mammals can contribute to the fact that a layer of litter that is too dense for young spiders is loosened and partially removed so that suitable areas for their settlement become free again.

Reproduction

The spiders become sexually mature in early autumn. When the rainy season sets in, which varies locally and annually between the end of March and the end of June, the male spiders leave their living tunnels and go in search of sexually mature females. After mating with one or more females in their living tubes, the males die. Life spans of more than forty years have been documented for female spiders; an age of several decades is not uncommon. The ability to raise offspring multiple times associated with longevity contributes significantly to the preservation of the species in their habitats that are rather unfavorable for spiders.

After mating, the females withdraw into their living tubes and close them with a plug made of earth. The eggs are laid during spring; the mother spun the eggs into a disc-shaped cocoon, which she attaches to the wall of the living tube with several threads. The brood hatches in midsummer and the carapace is about three millimeters long. For a particularly large female, a brood with 42 offspring is recorded; the average number is lower. The tube remains closed until autumn, a full year after mating, to protect the eggs and the brood from the summer heat. If the mating takes place very early and the autumn rains of the following year set in late, the living tubes can remain closed for much longer than a year.

In early autumn, the young spiders leave their mother's apartment tube and dig their own apartment tube near it, in which they grow into adult animals. They also keep a summer rest in closed residential tunnels, which is, however, much shorter. Young spiders that have left their mother's apartment tube and have not yet dug their own are particularly endangered by predators such as birds, frogs, lizards and other arthropods. Some young spiders that dig their burrows too close to the burrows of older spiders are quickly killed by them. In addition, cannibalism is a common occurrence among the young spiders. It is favored by the fact that the young spiders create their living tubes near the living tube of the mother animal. Often, due to the high population density, the rings of twigs around the residential tubes overlap each other, resulting in fatal encounters between neighbors.

Most young spiders that can dig a burrow will survive at least until summer, when the weather causes a high mortality rate. The poorer temperature and humidity regulation in the smaller living tunnels of young spiders, their less favorable ratio of body mass to body surface and the reduced food supply during the drought contribute to this. Spiders that have survived two summers are likely to live to be at least four years old. The proportion of young spiders that grow to sexual maturity is estimated at a maximum of 3.75 percent.

In sexually mature females, a year of offspring is followed by at least a year without brood, and they do not reproduce in the year they are fully grown. Adult females without brood do not seal their living tubes, but remain active.

Interaction with other animals

Gaius villosus is an important predator in the habitats he inhabits . Due to its size, it can also overwhelm small vertebrates, but its main diets are termites and ants . There is probably a connection between the preference for locations under acacias for building the residential tubes and the behavior of the preferred prey. The acacia parasitize scale insects , which in turn are the main prey of ants. The ants therefore form intensively used "roads" from their nests to the nearby acacias, while the areas between the trees or bushes are hardly used. Accordingly, Gaius villosus forms dense settlements under acacias. The areas between the acacias, which have hardly any branches for the entrances to the living tubes and little food, are not colonized by the spiders either.

Due to their hidden way of life and the fact that their living tubes are equipped with trap doors and the retractable "stocking" made of spider silk, adult specimens are well protected from predators. An exception are scorpions of the species Isometroides vescus , which feed exclusively on spiders that close their living tubes with trap doors. Gaius villosus can also fall victim to them, but confrontations can also be fatal for the Scorpio. Several times undamaged spiders have been found in their living tube below the drawn in "stocking", while an invaded Isometroides vescus was above and could not reach the prey.

A large number of unspecified mites often live in older residential tubes , which feed on the spider's leftover food and thus prevent the formation of mold . In rare cases, spiders encrusted with mites have been observed.

No further details are known about parasites either. In the literature, a finding of the empty pupal shell of a parasitic wasp has been mentioned. The oldest spider of the species Gaius villosus probably fell victim to a wasp in 2017 when it was at least 43 years old .

Bush fires

Bush fires are common in Australia and were an important ecological factor even before Europeans settled the continent. For the Wodjil as a typical habitat of Gaius villosus , an average of two natural bushfires in 100 years is assumed, which only occur in the dry summer months. The vegetation from acacias is partly dependent on bushfires for reproduction, within five years the vegetation of a fire site has renewed or recovered. The adult spiders and their brood can survive bushfires in their sealed living tubes, while growing spiders usually die from the fire. Even the most important prey animals, termites and ants, survive bushfires in their buildings and nests. However, the survival of the brood with the dams in their tunnels does not ensure that the habitat can be repopulated quickly after a bush fire.

After a fire, the living conditions of the surviving spiders are more difficult due to the loss of the undergrowth and the litter layer, so that a considerable proportion of the spiders that initially survived perish in the following months. The species spreads slowly over the ground into new or unoccupied habitats, and after a fire the young spiders no longer find a suitable habitat for a settlement. This puts Gaius villosus at a disadvantage compared to species whose populations fall completely victim to a fire, but which can colonize a new or vacated habitat with the help of flight threads through the air.

Long-term observation from 1974 to 2017

Already in 1968 and 1969 the arachnologist Barbara York Main carried out an investigation of the fauna of the tarantulas in the nature reserve North Bungulla Nature Reserve ( 31 ° 31 ′ 33.4 ″ S , 117 ° 35 ′ 28.9 ″ E ) and some of the living tubes of the species were considered long-lived known species Gaius villosus identified and marked. The nature reserve with an area of 104 hectares is located in the Shire of Tammin , in the wheat belt of the state of Western Australia , about 15 kilometers northeast of the village of Tammin at an altitude of about 330 meters above sea level. It is one of the few remnants of natural vegetation that was preserved in the region between 1920 and 1980 after the extensive creation of agricultural areas. -31.525937 117.591357

The nature reserve is a typical Gaius villosus habitat with vegetation of mulga and acacia thickets. The actual study area has an area of 40 × 26 meters. In its vicinity or immediately adjacent are termite mounds of the genus Drepanotermes and two large nests of the ant species Iridomyrmex purpureus . The termites and ants are important prey for spiders, but also for rabbits and short-billed hedgehogs , which can rummage through the litter layer in search of them and disturb the spiders. Barbara York Main grew up on a farm in the immediate vicinity.

From March 16, 1974, the residential tunnels of Gaius villosus were provided with numbered markings in the study area. Initially, only the spider's lifespan should be determined by marking the living tubes of juvenile specimens and occasional inspections. In the course of the investigation, the researchers realized that the study area offered ideal conditions for a more extensive demographic study. By the end of 1976, 64 residential tunnels had been marked. In the fall and winter of 1977, 37 were added, some of which belonged to undiscovered spiders from the two previous years. During the first marking and the sporadic controls, the diameters of trap doors and residential tubes were measured and the condition of the residential tubes, in particular whether they were closed, was documented. On June 22, 1975, the residential tube of the spider was marked, which decades later became known as Number 16 .

During the first few years, the study provided basic information on the biology of Gaius villosus . The life stories of all spiders and their offspring were documented over several generations, the probability of survival was also examined in relation to the weather in different years, the reproductive behavior of female spiders in successive years was observed and the spread of the offspring after leaving the mother's tube was tracked. Although Gaius villosus itself is widespread, the results of the investigation are significant for numerous other rare and endangered species of trapdoor spiders, especially with regard to the inability to colonize new habitats. Many of these species have only very small areas of distribution or are only known from one site, so that comparatively minor interventions in the natural balance can destroy the entire species.

On October 31, 2016, the residential tube of Number 16 was found empty and with a perforated trap door. Apparently Number 16 had been killed by a parasitic wasp within the six months since the last inspection .

Hazard and protection

Gaius villosus occurs frequently in places within its large range. The species is not considered endangered.

As a poorly mobile and long-lived species with a low reproductive rate, Gaius villosus is more affected by habitat changes than other spiders. Bushfires pose a particular threat, as they can severely impair a population and not only occur naturally, but are also used in a targeted and frequent manner in forestry.

The grazing of land by ungulates leads to the breaking up of the top soil layer, increased soil erosion and possibly reduced availability of potential prey. Grazing destroys the litter layer and also destroys the entrances or all of the living tubes. Gaius villosus cannot survive on pastureland . On agriculturally used areas, the species is only detected where the grazing animals have no access, for example on tree stumps or rocks. This creates small populations isolated from one another, between which no genetic exchange takes place and which also have no possibility of expansion. When building their burrow in a densely populated area, wild rabbits can destroy several living tubes of Gaius villosus , which means death for adult spiders.

The long-term observation of a population of Gaius villosus , which lasted more than 40 years, gives rise to the assumption that populations can only persist with at least 20 older female spiders (“matriarchs”). In addition, links to neighboring populations are likely to be required to exchange with during periods of poor reproductive conditions.

One way to protect trapdoor spiders is to fence in areas and exempt them from grazing and forestry. Healthy populations of Gaius villosus are characterized by the presence of adult and growing spiders, while areas populated exclusively by adult specimens indicate poor reproduction and decline.

Systematics

Gaius villosus , adult female, drawing from the first description

The monotypical genus Gaius Rainbow , 1914 includes, in addition to the only described species, Gaius villosus Rainbow , 1914 several still undescribed species.

The genus Gaius forms the Aganippini tribe with four other genera . Your subfamily Arbanitinae includes about 150 species in ten genera and is in the family Idiopidae .

Initial description

The first description of the genus Gaius with the type species Gaius villosus was made in 1914 by the Australian arachnologist William Joseph Rainbow in an edition of the Records of the Australian Museum . Rainbow described the species after a female specimen, the generic and species characteristics he cited are therefore unsuitable for a determination from today's perspective.

Type material

The type species of the genus Gaius Rainbow , 1914 is Gaius villosus , due to the monotype of the genus. The holotype of Gaius villosus is in the collection of the Australian Museum in Sydney .

etymology

The species name Gaius is, according to the first descriptor William Joseph Rainbow, a proper name from the Bible. This can only be Gaius of Ephesus , who is mentioned repeatedly in the New Testament ( Rom 16:23 EU ). Without further details, Rainbow stated the meaning of the word that it was a "Lord" and an "earthen individual". From this he derived the name for the burrowing, i.e. earth-dwelling species of spider.

For the species name villosus , Rainbow did not provide an explanation in the first description. The origin are the Latin nouns vellus , with which the still coherent fleece made of sheep's wool was referred to, and villus for the shaggy, woolly hair of the animals . Derived from this, the adjective villosus means shaggy, rough, hairy in German . The species name refers to the thick hair on the body and legs of Gaius villosus .

Synonyms and nouns dubium

Anidiops villosus ( Rainbow , 1914): In 1957 the Australian arachnologist Barbara York Main synonymizedthe genus Gaius with Anidiops . Gaius wasreinstatedin 2017 by a group around the arachnologist Michael G. Rix , who also belonged to Main, as a monotypic genus with the species Gaius villosus .

Gaius hirsutus Rainbow & Pulleine , 1918: the species described after only onefemale specimen foundeast of Port Augusta in South Australia was synonymous with Anidiops manstridgei ( Pocock , 1897) (currently Idiosoma manstridgei ( Pocock , 1897))by Main in 1957. In 2017, the synonymization by Rix et al. repealed and Gaius hirsutus declared the noun dubium .

literature

Barbara York Main: Biology of Aganippine trapdoor spiders (Mygalomorphae: Ctenizidae) . In: Australian Journal of Zoology 1957, Volume 5, Number 4, pp. 402-473, doi : 10.1071 / ZO9570402 (dissertation).
Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) . In: Bulletin of the British Arachnological Society 1978, Volume 4, No. 4, pp. 161-175, Online PDF , 1.6 MB.
Leanda Denise Mason, Grant Wardell-Johnson and Barbara York Main: The longest-lived spider: mygalomorphs dig deep, and persevere . In: Pacific Conservation Biology , April 19, 2018, doi : 10.1071 / PC18015 .
William Joseph Rainbow : Studies in Australian Araneidae - No. 6. The Terretelariae . In: Records of the Australian Museum 1913–1915, Volume 10, No. 8, pp. 187–270, here pp. 195–199 digitized version (first description, published on August 14, 1914).
Michael G. Rix et al .: The Australasian spiny trapdoor spiders of the family Idiopidae (Mygalomorphae: Arbanitinae): a relimitation and revision at the generic level . In: Invertebrate Systematics , 2017, Volume 31, pp. 566-634, doi : 10.1071 / IS16065 .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f ^g ^h Michael G. Rix et al .: The Australasian spiny trapdoor spiders of the family Idiopidae , pp. 618–620.
↑ ^a ^b ^c ^d ^e Michael G. Rix et al .: The Australasian spiny trapdoor spiders of the family Idiopidae , pp. 620–621.
↑ ^a ^b Barbara York Main: Historical ecology, responses to current ecological changes and conservation of Australian spiders . In: Journal of Insect Conservation 2001, Volume 5, pp. 9-25, doi : 10.1023 / A: 1011337914457 .
↑ ^a ^b ^c ^d ^e Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , p. 161.
^ ^A ^b Barbara York Main: Biology of Aganippine trapdoor spiders , p. 444.
↑ ^a ^b Michael G. Rix et al .: The Australasian spiny trapdoor spiders of the family Idiopidae , pp. 569-572.
^ Southwestern Australia , WWF website , accessed May 16, 2018.
^ ^A ^b Department of Environment and Conservation (Ed.): Threatened Trapdoor Spiders of the Avon . Department of Environment and Conservation and WWF, no location, no year (2009?), Online PDF , 5.0 MB.
↑ Barbara York Main: Biology of Aganippine trapdoor spiders , p. 451.
^ ^A ^b Barbara York Main: Adaptive Radiation of Trapdoor Spiders . In: Australian Museum Magazine 1957, Volume 12, No. 5, pp. 160-163, Online PDF , 9.0 MB.
^ ^A ^b Barbara York Main: Interactions of Water, Plants and Ground-Dwelling Fauna: Water Harvesting and Tapping by Trapdoor Spiders . In: Landscapes. The Journal of the International Center for Landscape and Language 2010, Volume 4, No. 1, Article 31, Online PDF , 1.7 MB.
↑ JR Henschel: Tool Use by Spiders: Stone Selection and Placement by Corolla Spiders Ariadna (Segestriidae) of the Namib Desert . In: Ethology 1995, Volume 101, No. 3, pp. 187-199, doi : 10.1111 / j.1439-0310.1995.tb00357.x .
↑ ^a ^b ^c Barbara York Main: An unusual method of spoil disposal during burrow excavation by the trapdoor spider Anidiops villosus (Rainbow) . In: The Western Australian Naturalist 1979, Vol. 14, No. 5, pp. 115-117, ISSN 0508-4865 .
↑ Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 447-448.
↑ ^a ^b ^c ^d Barbara York Main: Survival of trapdoor spiders during and after fire . In: CALM Science Supplement 1995, Volume 4, pp. 207-216, Online PDF , 132 kB.
↑ Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 164–166.
↑ ^a ^b ^c ^d Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 162-164.
↑ Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , p. 173.
↑ ^a ^b Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 170-171.
^ ^A ^b Barbara York Main: Distribution and Adaptive Diversity of Trapdoor Spiders . In: Australian Natural History 1968, Volume 16, No. 2, pp. 49-53, Online PDF , 9.1 MB.
^ ^A ^b ^c Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 171–172.
↑ Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 454-455.
↑ Barbara York Main: Biology of Aganippine trapdoor spiders , p. 452.
↑ Barbara York Main: Taxonomy and biology of the genus Isometroides Keyserling (Scorpionida) . In: Australian Journal of Zoology 1956, Volume 4, No. 2, pp. 158-164, doi : 10.1071 / ZO9560158 .
^ LE Koch: The taxonomy, geographic distribution and evolutionary radiation of Australo-Papuan Scorpions . In: Records of the Western Australian Museum 1977, Volume 7, Part 2, pp. 144–151, Online PDF , 24.4 MB.
↑ Barbara York Main: Biology of Aganippine trapdoor spiders , p. 449.
↑ Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 453-454.
↑ ^a ^b ^c Leanda Denise Mason, Grant Wardell-Johnson and Barbara York Main: The longest-lived spider: mygalomorphs dig deep, and persevere , S. B – C.
^ ^A ^b ^c ^d Alan L. Yen: Australian spiders: an opportunity for conservation . In: Records of the Western Australian Museum Supplement 1995, No. 52, pp. 39-47, ISSN 0313-122X , digitized .
↑ ^a ^b ^c Michael G. Rix et al .: Where have all the spiders gone? The decline of a poorly known invertebrate fauna in the agricultural and arid zones of southern Australia . In: Austra Entomology 2016, Volume 56, No. 1, pp. 14-22, doi : 10.1111 / aen.12258 .
↑ Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , p. 174.
^ ^A ^b A. Chapman: Introduction to Yorkrakine Rock, East Yorkrakine and North Bungulla Nature Reserves . In: Records of the Western Australian Museum Supplement 1980, No. 12, pp. 9-13, ISSN 0313-122X , digitized .
↑ ^a ^b Leanda Denise Mason, Grant Wardell-Johnson and Barbara York Main: The longest-lived spider: mygalomorphs dig deep, and persevere , SA
↑ Robyn Williams, Vicki Laurie and Barbara Yok Main: Barbara York Main: Spider Woman , transcript of a radio interview broadcast by the Australian Broadcasting Corporation on Ockham's Razor on September 15, 2013, accessed on May 18, 2018.
^ ^A ^b William Joseph Rainbow: Studies in Australian Araneidae .
↑ Alois Walde: Latin Etymological Dictionary , second revised edition. Carl Winter, Heidelberg 1910, digitized version , lemmata vellus and villus .
^ ^A ^b Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 426-427.
↑ Barbara York Main: Biology of Aganippine trapdoor spiders , p. 411.
↑ William Joseph Rainbow and Robert H. Pulleine: Australian Trapdoor spiders . In: Records of the Australian Museum 1918, Volume 12, No. 7, pp. 81–169, panels xii – xxiv, here pp. 83, 102–103, panel xxi, digitized .

Web links

Commons : Gaius villosus - collection of images

Gaius in the World Spider Catalog Gaius villosus in the World Spider Catalog

[Rix_618-1] ↑ ^a ^b ^c ^d ^e ^f ^g ^h Michael G. Rix et al .: The Australasian spiny trapdoor spiders of the family Idiopidae , pp. 618–620.

[Rix_620-2] Michael G. Rix et al .: The Australasian spiny trapdoor spiders of the family Idiopidae , pp. 620–621.

[Main_2001-3] Barbara York Main: Historical ecology, responses to current ecological changes and conservation of Australian spiders . In: Journal of Insect Conservation 2001, Volume 5, pp. 9-25, doi : 10.1023 / A: 1011337914457 .

[Main_161-4] Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , p. 161.

[Main_444-5] A ^b Barbara York Main: Biology of Aganippine trapdoor spiders , p. 444.

[Rix_569-6] Michael G. Rix et al .: The Australasian spiny trapdoor spiders of the family Idiopidae , pp. 569-572.

[WWF-7] Southwestern Australia , WWF website , accessed May 16, 2018.

[DEC-8] A ^b Department of Environment and Conservation (Ed.): Threatened Trapdoor Spiders of the Avon . Department of Environment and Conservation and WWF, no location, no year (2009?), Online PDF , 5.0 MB.

[Main_451-9] Barbara York Main: Biology of Aganippine trapdoor spiders , p. 451.

[Main_1957-10] A ^b Barbara York Main: Adaptive Radiation of Trapdoor Spiders . In: Australian Museum Magazine 1957, Volume 12, No. 5, pp. 160-163, Online PDF , 9.0 MB.

[Main_2010-11] A ^b Barbara York Main: Interactions of Water, Plants and Ground-Dwelling Fauna: Water Harvesting and Tapping by Trapdoor Spiders . In: Landscapes. The Journal of the International Center for Landscape and Language 2010, Volume 4, No. 1, Article 31, Online PDF , 1.7 MB.

[Henschel-12] JR Henschel: Tool Use by Spiders: Stone Selection and Placement by Corolla Spiders Ariadna (Segestriidae) of the Namib Desert . In: Ethology 1995, Volume 101, No. 3, pp. 187-199, doi : 10.1111 / j.1439-0310.1995.tb00357.x .

[Main_1979-13] Barbara York Main: An unusual method of spoil disposal during burrow excavation by the trapdoor spider Anidiops villosus (Rainbow) . In: The Western Australian Naturalist 1979, Vol. 14, No. 5, pp. 115-117, ISSN 0508-4865 .

[Main_447-14] Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 447-448.

[Main_1995-15] Barbara York Main: Survival of trapdoor spiders during and after fire . In: CALM Science Supplement 1995, Volume 4, pp. 207-216, Online PDF , 132 kB.

[Main_164-16] Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 164–166.

[Main_162-17] Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 162-164.

[Main_173-18] Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , p. 173.

[Main_170-19] Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 170-171.

[Main_1968-20] A ^b Barbara York Main: Distribution and Adaptive Diversity of Trapdoor Spiders . In: Australian Natural History 1968, Volume 16, No. 2, pp. 49-53, Online PDF , 9.1 MB.

[Main_171-21] A ^b ^c Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , pp. 171–172.

[Main_454-22] Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 454-455.

[Main_452-23] Barbara York Main: Biology of Aganippine trapdoor spiders , p. 452.

[Main_1956-24] Barbara York Main: Taxonomy and biology of the genus Isometroides Keyserling (Scorpionida) . In: Australian Journal of Zoology 1956, Volume 4, No. 2, pp. 158-164, doi : 10.1071 / ZO9560158 .

[Koch-25] LE Koch: The taxonomy, geographic distribution and evolutionary radiation of Australo-Papuan Scorpions . In: Records of the Western Australian Museum 1977, Volume 7, Part 2, pp. 144–151, Online PDF , 24.4 MB.

[Main_449-26] Barbara York Main: Biology of Aganippine trapdoor spiders , p. 449.

[Main_453-27] Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 453-454.

[Mason_B-28] Leanda Denise Mason, Grant Wardell-Johnson and Barbara York Main: The longest-lived spider: mygalomorphs dig deep, and persevere , S. B – C.

[Yen-29] A ^b ^c ^d Alan L. Yen: Australian spiders: an opportunity for conservation . In: Records of the Western Australian Museum Supplement 1995, No. 52, pp. 39-47, ISSN 0313-122X , digitized .

[Rix_2016-30] Michael G. Rix et al .: Where have all the spiders gone? The decline of a poorly known invertebrate fauna in the agricultural and arid zones of southern Australia . In: Austra Entomology 2016, Volume 56, No. 1, pp. 14-22, doi : 10.1111 / aen.12258 .

[Main_174-31] Barbara York Main: Biology of the arid-adapted Australian trapdoor spider Anidiops villosus (Rainbow) , p. 174.

[Chapman-32] A ^b A. Chapman: Introduction to Yorkrakine Rock, East Yorkrakine and North Bungulla Nature Reserves . In: Records of the Western Australian Museum Supplement 1980, No. 12, pp. 9-13, ISSN 0313-122X , digitized .

[Mason_A-33] Leanda Denise Mason, Grant Wardell-Johnson and Barbara York Main: The longest-lived spider: mygalomorphs dig deep, and persevere , SA

[ABC-34] Robyn Williams, Vicki Laurie and Barbara Yok Main: Barbara York Main: Spider Woman , transcript of a radio interview broadcast by the Australian Broadcasting Corporation on Ockham's Razor on September 15, 2013, accessed on May 18, 2018.

[Rainbow-35] A ^b William Joseph Rainbow: Studies in Australian Araneidae .

[Walde-36] Alois Walde: Latin Etymological Dictionary , second revised edition. Carl Winter, Heidelberg 1910, digitized version , lemmata vellus and villus .

[Main_426-37] A ^b Barbara York Main: Biology of Aganippine trapdoor spiders , pp. 426-427.

[Main_411-38] Barbara York Main: Biology of Aganippine trapdoor spiders , p. 411.

[Rainbow_Pulleine-39] William Joseph Rainbow and Robert H. Pulleine: Australian Trapdoor spiders . In: Records of the Australian Museum 1918, Volume 12, No. 7, pp. 81–169, panels xii – xxiv, here pp. 83, 102–103, panel xxi, digitized .