Argyrodes


Argyrodes, also called dewdrop spiders, is a genus of comb-footed spiders that was first described by Eugène Louis Simon in 1864. They occur worldwide, and are best known for their kleptoparasitism. They can spin their own webs, but tend to invade and reside in their hosts' webs. This relationship can be commensal or even mutual if the dewdrop spider feeds on small trapped insects that are not eaten by the host. Some species can even prey upon the host.
The genus name is a combination of the Ancient Greek "argyros", meaning "silver", and the suffix "-odes", meaning "like".

Description

Most species are relatively small, and many are black with silvery markings. A. incursus has a body length of, while A. fissifrons has a body length of about. The body has a characteristic conical or triangle shape with a shorter third pair of legs, common in web dwelling spiders. The silver coloration of Argyrodes may be able to attract moths and other insects as it stimulates their photoreceptors and may resemble starlight.
The most striking anatomical character of Argyrodes and related other genera is a prosomatic sexual dimorphism, the cephalic part of male's cephalothorax being often strangely modified by "deformations" such as knobs, notches and sulci. During copulation they are gripped by the chelicerae of the female to contact the secretion of an underlying exocrine organ discovered and named clypeal or acronal gland by André Lopez.

Distribution

Most Argyrodes are found in the tropics, though fifteen species are found in the United States. A. elevatus is found in the southern US, A. nephilae in Florida and A. pluto in Maryland, Virginia, and Missouri. The latter species has been reported as far south as Chihuahua and Jamaica as well.

Behavior

Kleptoparasitism

Argyrodes are kleptoparasitic spiders that live on the webs created by orb-weaver spiders. These spiders feed on the small prey items caught in the host webs that they parasitize. In some instances, Argyrodes may even feed on previously digested carcasses that remain on the web. While these spiders are well known for being kleptoparasitic, they are also arachnophagous, meaning they prey on other spiders. Argyrodes will wait for a time when the host spider is vulnerable, such as during molting, and will attack and feed on it. This is true for the host spider's offspring as well, however Agyrodes will only feed on other spiders in some instances.
It has been suggested that Argyrodes may have a mutualistic relationship with the host. The silver coloration of Argyrodes was found to attract more prey, particularly moths, to the host's web. This allows for larger prey items to be attracted for the host spider while Argyrodes is able to consume the smaller unwanted prey. A common misconception about Argyrodes is that it steals prey from the host spider, but recent research has shown that Argyrodes rarely steals large prey items from the host, and only eats what the host spider typically does not want. They have been noticed in complex Joro spider webs, for example.
Kleptoparasitic spiders such as Argyrodes tend to prefer larger host webs over small ones, and multiple spiders often inhabit the same host web. Clustered webs were found to be preferred by Arygrodes, but only because these webs are generally larger than isolated ones. There does not appear to be any preference for clustered webs over isolated webs when comparing the number of spiders per web area. Kleptoparasitic spiders tend to spend much of their time on the outskirts of the host web, using this area as a safe place outside of the host spiders typical monitoring range. In addition to stealing food from the host web, dewdrop spiders are also known to use the host web as a location for mating as well as a place to hang their egg sacs.
In South America, Argyrodes spiders are the most common guest species in the webs of the colonial spiders Anelosimus eximius, where they primarily inhabit the upper strands of the large webs and descend into the main web to feed on prey remains.

Stridulation

Two South African species, A. stridulator and A. convivans, collected from the web of Trichonephila inaurata madagascariensis, have a stridulating organ consisting of two ridged, oval patches on the carapace that are scraped against a chitinous ring on the anterior apex of the abdomen.

Species

, this genus includes 85 species and five subspecies, found in Asia, South America, North America, Oceania, Africa, the Caribbean, on the Canary Islands, and Saint Helena:
  • Argyrodes abscissus O. Pickard-Cambridge, 1880 – Madagascar
  • Argyrodes alannae Grostal, 1999 – Eastern Australia
  • Argyrodes ambalikae Tikader, 1970 – India
  • Argyrodes amboinensis Thorell, 1878 – Indonesia, New Guinea, New Caledonia
  • Argyrodes antipodianus O. Pickard-Cambridge, 1880 – Australia, New Caledonia, New Zealand
  • Argyrodes apiculatus Thorell, 1895 – Myanmar
  • Argyrodes argentatus O. Pickard-Cambridge, 1880 – India, Indonesia to China. Introduced to Hawaii
  • Argyrodes argyrodes – Mediterranean to West Africa. Introduced to St. Helena, South Africa, Seychelles, Hawaii
  • Argyrodes atriapicatus Strand, 1906 – Ethiopia
  • Argyrodes bandanus Strand, 1911 – Indonesia
  • Argyrodes benedicti Lopez, 1988 – French Guiana
  • Argyrodes binotatus Rainbow, 1915 – Australia
  • Argyrodes bonadea – India, China, Korea, Taiwan, Japan, Philippines
  • Argyrodes borbonicus Lopez, 1990 – Réunion
  • Argyrodes callipygus Thorell, 1895 – Myanmar
  • Argyrodes calmettei Lopez, 1990 – Réunion
  • Argyrodes chionus Roberts, 1983 – Seychelles
  • Argyrodes chiriatapuensis Tikader, 1977 – India
  • Argyrodes chounguii Lopez, 2010 – Mayotte
  • Argyrodes coactatus Lopez, 1988 – French Guiana
  • Argyrodes cognatus – Seychelles
  • Argyrodes convivans Lawrence, 1937 – Zimbabwe, South Africa
  • Argyrodes cylindratus Thorell, 1898 – China, Myanmar to Japan
  • Argyrodes cyrtophorae Tikader, 1963 – India
  • Argyrodes delicatulus Thorell, 1878 – Indonesia
  • Argyrodes dipali Tikader, 1963 – India
  • Argyrodes elevatus Taczanowski, 1873 – USA to Argentina, Galapagos
  • Argyrodes exlineae – Kenya
  • Argyrodes fasciatus Thorell, 1893 – Singapore
  • Argyrodes fissifrons O. Pickard-Cambridge, 1869 – Sri Lanka to Indonesia, Papua New Guinea, China, Australia
  • * A. f. terressae Thorell, 1891 – India
  • Argyrodes fissifrontellus Saaristo, 1978 – Seychelles
  • Argyrodes flavescens O. Pickard-Cambridge, 1880 – India, Sri Lanka to Japan, New Guinea
  • Argyrodes flavipes Rainbow, 1916 – Australia
  • Argyrodes fragilis Thorell, 1877 – Indonesia
  • Argyrodes gazedes Tikader, 1970 – India
  • Argyrodes gazingensis Tikader, 1970 – India
  • Argyrodes gemmatus Rainbow, 1920 – Australia
  • Argyrodes gouri Tikader, 1963 – India
  • Argyrodes gracilis – Australia, New Caledonia, Samoa
  • Argyrodes hawaiiensis Simon, 1900 – Hawaii
  • Argyrodes ilipoepoe Rivera & Gillespie, 2010 – Hawaii
  • Argyrodes incertus Wunderlich, 1987 – Canary Islands
  • Argyrodes incisifrons Keyserling, 1890 – Australia
  • Argyrodes insectus Schmidt, 2005 – Cape Verde
  • Argyrodes jamkhedes Tikader, 1963 – India
  • Argyrodes kratochvili – Kenya
  • Argyrodes kualensis Hogg, 1927 – Malaysia
  • Argyrodes kumadai Chida & Tanikawa, 1999 – China, Taiwan, Japan
  • Argyrodes laja Rivera & Gillespie, 2010 – Hawaii
  • Argyrodes latifolium Liu, Irfan & Peng, 2019 – China
  • Argyrodes lepidus O. Pickard-Cambridge, 1880 – New Zealand
  • Argyrodes levuca Strand, 1915 – Fiji
  • Argyrodes lucmae Chamberlin, 1916 – Peru
  • Argyrodes maculiger Strand, 1911 – Indonesia
  • Argyrodes margaritarius – Australia
  • Argyrodes mellissi – St. Helena
  • * A. m. poecilior Strand, 1913 – DR Congo, Uganda
  • Argyrodes minax O. Pickard-Cambridge, 1880 – Madagascar, Comoros
  • Argyrodes miniaceus – India, Korea, Japan to Australia
  • Argyrodes modestus Thorell, 1899 – Cameroon
  • Argyrodes nephilae Taczanowski, 1873 – United States, Caribbean to Argentina, Galapagos. Introduced to India
  • Argyrodes parcestellatus Simon, 1909 – Vietnam
  • Argyrodes pluto Banks, 1906 – United States, Mexico, Jamaica
  • Argyrodes praeacutus Simon, 1903 – Equatorial Guinea
  • Argyrodes projeles Tikader, 1970 – India
  • Argyrodes reticola Strand, 1911 – Indonesia
  • Argyrodes rostratus Blackwall, 1877 – Seychelles
  • Argyrodes samoensis O. Pickard-Cambridge, 1880 – New Caledonia, Samoa
  • Argyrodes scapulatus Schmidt & Piepho, 1994 – Cape Verde
  • Argyrodes scintillulanus O. Pickard-Cambridge, 1880 – India, Sri Lanka
  • Argyrodes sextuberculosus Strand, 1908 – Mozambique, South Africa, Madagascar
  • * A. s. dilutior – Ethiopia
  • Argyrodes strandi – Ethiopia
  • Argyrodes stridulator Lawrence, 1937 – South Africa
  • Argyrodes sublimis L. Koch, 1872 – Fiji
  • Argyrodes sundaicus – Thailand, Indonesia, Papua New Guinea
  • Argyrodes tenuis Thorell, 1877 – Indonesia
  • * A. t. infumatus Thorell, 1878 – Indonesia
  • Argyrodes tripunctatus Simon, 1877 – Philippines
  • Argyrodes unimaculatus – Samoa, Tongatabu, Niue
  • Argyrodes vatovae – Ethiopia
  • Argyrodes viridis – Madagascar, Réunion
  • Argyrodes vittatus Bradley, 1877 – New Guinea
  • Argyrodes weyrauchi Exline & Levi, 1962 – Peru
  • Argyrodes wolfi Strand, 1911 – New Guinea
  • Argyrodes yunnanensis Xu, Yin & Kim, 2000 – China
  • Argyrodes zhui Zhu & Song, 1991 – China
  • Argyrodes zonatus – Equatorial Guinea, East Africa, South Africa, Eswatini, Madagascar, Réunion, Mayotte
  • * A. z. occidentalis Simon, 1903 – Guinea-Bissau
  • A. aculeatus
  • A. acuminatus Keyserling, 1891
  • A. acuminatus
  • A. affinis
  • A. alticeps Keyserling, 1891
  • A. altus Keyserling, 1891
  • A. amates Exline & Levi, 1962
  • A. americanus
  • A. analiae González & Carmen, 1996
  • A. andamanensis Tikader, 1977
  • A. angulipalpis
  • A. anomalus
  • A. argenteolus
  • A. argentiopunctatus Rainbow, 1916
  • A. argyrodiformis
  • A. arthuri Exline & Levi, 1962
  • A. atopus Chamberlin & Ivie, 1936
  • A. baboquivari Exline & Levi, 1962
  • A. barycephalus Roberts, 1983
  • A. birgitae
  • A. bryantae Exline & Levi, 1962
  • A. campestratus
  • A. canariensis
  • A. cancellatus
  • A. carnicobarensis Tikader, 1977
  • A. caronae González & Carmen, 1996
  • A. caudatus
  • A. ceraosus Zhu & Song, 1991
  • A. chicaensis González & Carmen, 1996
  • A. chickeringi Exline & Levi, 1962
  • A. cochleaformus
  • A. colubrinus
  • A. cometes
  • A. concisus Exline & Levi, 1962
  • A. conus González & Carmen, 1996
  • A. convolutus Exline & Levi, 1962
  • A. cordillera
  • A. corniger
  • A. cristinae González & Carmen, 1996
  • A. crucinotus Bösenberg & Strand, 1906
  • A. cubensis Exline & Levi, 1962
  • A. cylindricus Franganillo, 1936
  • A. cylindrogaster
  • A. darlingtoni Exline & Levi, 1962
  • A. davisi Exline & Levi, 1962
  • A. delicatulus
  • A. dracus Chamberlin & Ivie, 1936
  • A. duckensis González & Carmen, 1996
  • A. ecaudatus
  • A. exiguus Exline & Levi, 1962
  • A. fictilium
  • A. flagellum
  • A. flagellum
  • A. flavonotatus
  • A. floridanus Banks, 1900
  • A. frontatus Banks, 1908
  • A. fulvus Exline & Levi, 1962
  • A. fur Bösenberg & Strand, 1906
  • A. gansuensis Zhu, 1998
  • A. gapensis Exline & Levi, 1962
  • A. gertschi Exline & Levi, 1962
  • A. globosus Keyserling, 1884
  • A. godmani Exline & Levi, 1962
  • A. haitensis Exline & Levi, 1962
  • A. helminthoides
  • A. huangsangensis Yin, Peng & Bao, 2004
  • A. hyrcanus Logunov & Marusik, 1990
  • A. iguazuensis González & Carmen, 1996
  • A. indignus Chamberlin & Ivie, 1936
  • A. irroratus
  • A. jamaicensis Exline & Levi, 1962
  • A. jeanneli
  • A. labiatus Zhu & Song, 1991
  • A. lactifer
  • A. laraensis González & Carmen, 1996
  • A. leonensis Exline & Levi, 1962
  • A. levii Zhu & Song, 1991
  • A. longispinus Saito, 1933
  • A. longissimus
  • A. longus
  • A. manta
  • A. mariae González & Carmen, 1996
  • A. martinae
  • A. melanosoma
  • A. metaltissimus
  • A. mexicanus Exline & Levi, 1962
  • A. miyashitai Tanikawa, 1998
  • A. monoceros
  • A. montanus Keyserling, 1884
  • A. morretensis González & Carmen, 1996
  • A. nasicus
  • A. nataliae González & Carmen, 1996
  • A. nigronodosus Rainbow, 1912
  • A. nigroris Yoshida, Tso & Severinghaus, 2000
  • A. nipponicus Kumada, 1990
  • A. obscurus Keyserling, 1884
  • A. orbitus Zhu, 1998
  • A. oris González & Carmen, 1996
  • A. ornatissimus
  • A. pachysomus Chamberlin & Ivie, 1936
  • A. palmarensis González & Carmen, 1996
  • A. paradoxus Taczanowski, 1873
  • A. parvior Chamberlin & Ivie, 1936
  • A. parvus
  • A. patersoniensis
  • A. pavesii
  • A. peruensis Exline & Levi, 1962
  • A. pignalitoensis González & Carmen, 1996
  • A. pizai
  • A. plaumanni Exline & Levi, 1962
  • A. pozonae
  • A. proboscifer
  • A. pulcher
  • A. pusillus Saaristo, 1978
  • A. quasiobtusus Exline & Levi, 1962
  • A. recurvatus Saaristo, 1978
  • A. remotus
  • A. rhomboides Yin, Peng & Bao, 2004
  • A. rigidus Exline & Levi, 1962
  • A. rioensis Exline & Levi, 1962
  • A. rorerae
  • A. rossi Exline & Levi, 1962
  • A. rostratus
  • A. rufopictus
  • A. russulus
  • A. saganus
  • A. schlingeri Exline & Levi, 1962
  • A. setipes
  • A. sicki Exline & Levi, 1962
  • A. simoni
  • A. sinicus Zhu & Song, 1991
  • A. sinuatus
  • A. sjostedti
  • A. socius Chamberlin & Ivie, 1936
  • A. solidao Levi, 1967
  • A. spinicaudatus
  • A. spinosus
  • A. spinosus Keyserling, 1884
  • A. striatus Keyserling, 1891
  • A. subflavus Exline & Levi, 1962
  • A. sullana
  • A. taeter Exline & Levi, 1962
  • A. tanikawai
  • A. triangularis Taczanowski, 1873
  • A. triangulatus
  • A. triangulus
  • A. trigonum
  • A. trituberculatus Becker, 1879
  • A. ululabilis Keyserling, 1891
  • A. urquharti
  • A. v-notatus
  • A. vadoensis González & Carmen, 1996
  • A. velhaensis González & Carmen, 1996
  • A. vexus Chamberlin & Ivie, 1936
  • A. vittatulus
  • A. woytkowskii Exline & Levi, 1962
  • A. xiphias Thorell, 1887
  • A. yacuiensis González & Carmen, 1996
  • A. yesoensis Saito, 1934
  • A. yutoensis González & Carmen, 1996
Nomina dubia
  • A. meus Strand, 1907
  • A. silvicola Saito, 1934