Theridiidae
Guides
Anelosimus
cobweb spiders
Anelosimus is a genus of cobweb spiders (Theridiidae) renowned as a model system for studying the evolution of sociality in arachnids. The genus contains approximately 75 species exhibiting the full spectrum of social organization, from solitary to highly social (quasisocial). Eight quasisocial species have been documented, more than any other spider genus. Social species such as Anelosimus eximius form massive communal webs housing tens of thousands of individuals, while solitary species occur at higher altitudes and latitudes. The genus is cosmopolitan, with significant diversity in the Americas, Madagascar, and Australasia.
Anelosimus analyticus
Anelosimus analyticus is a species of cobweb spider in the family Theridiidae. It was described by Chamberlin in 1924. The species is found in the United States and Mexico. It belongs to a genus that includes both solitary and subsocial species, though the social behavior of A. analyticus specifically has not been documented.
Argyrodes elevatus
dew-drop spider, American Dewdrop Spider
Argyrodes elevatus is a kleptoparasitic spider in the family Theridiidae that steals food from the webs of other spiders rather than building its own. Adults measure 4–7 mm in length, with males smaller than females. The species exhibits specialized adaptations for stealth, including vibrational detection of host activity, rapid prey theft completed in under 12 seconds, and nocturnal activity patterns that oppose those of diurnal host species. Courtship involves males presenting silk-wrapped prey as nuptial gifts to females.
Argyrodes nephilae
dewdrop spider
Argyrodes nephilae is a small cobweb spider in the family Theridiidae, commonly known as a dewdrop spider. It lives as a kleptoparasite in the webs of large orb-weaving spiders, particularly those in the genus Nephila. The species ranges from the United States through Central and South America to Argentina and the Galapagos Islands, with introduced populations in India.
Argyrodes pluto
Argyrodes pluto is a species of cobweb spider in the family Theridiidae. It is found in the United States, Mexico, and Jamaica. Like other members of the genus Argyrodes, it is likely a kleptoparasite that lives on the webs of larger orb-weaving spiders, though specific behavioral observations for this species are not documented.
Asagena
Asagena is a genus of cobweb spiders (family Theridiidae) established by Carl Jakob Sundevall in 1833. It comprises nine species distributed across North America, Europe, Asia, and North Africa. Members are small spiders (2.4–5.9 mm body length) that construct webs in sheltered microhabitats including under stones, in leaf litter, under bark, and in moss. The genus was formerly classified within Steatoda.
Asagena americana
Two-spotted Cobweb Spider, Twospotted Cobweb Spider
Asagena americana, commonly known as the two-spotted cobweb spider, is a small theridiid spider native to North America. Males are notably robust with short, muscular legs and possess a stridulating organ used to produce sound during courtship. Females construct cobwebs in concealed microhabitats including under stones, in leaf litter, under bark, and in moss. The species exhibits pronounced sexual dimorphism in body form and is frequently preyed upon by mud dauber wasps.
Asagena fulva
Red-and-white Asagena
Asagena fulva is a small cobweb spider in the family Theridiidae, found in the southwestern United States and Mexico. Females range from 3–5.9 mm in body length, males from 2.4–5 mm. The species appears distinctly redder with more white markings than its congener A. americana. It has been observed in association with harvester ant nests, suggesting possible ant specialization.
Canalidion montanum
Canalidion montanum is a small tangle-web spider (family Theridiidae) and the sole species in the monotypic genus Canalidion. Originally described as Theridion montanum by James Emerton in 1882, it was transferred to its own genus by J. Wunderlich in 2018 based on distinctive cheliceral dentition and male genitalic morphology. The species has a holarctic distribution, occurring across northern North America and Eurasia.
Chrosiothes
Chrosiothes is a genus of comb-footed spiders in the family Theridiidae, established by Eugène Louis Simon in 1894. The genus contains 27 species distributed primarily in the New World, with most species occurring from the United States to Brazil. Males are noticeably smaller than females, with females of C. jamaicensis measuring approximately 2.9 mm compared to 1.6 mm for males. The genus is considered a senior synonym of Theridiotis.
Chrosiothes jenningsi
Chrosiothes jenningsi is a species of cobweb spider in the family Theridiidae. It was described by Piel in 1995. The species is known from the United States. As a member of Theridiidae, it constructs irregular, tangled webs. Very few observations of this species have been documented.
Chrosiothes jocosus
Chrosiothes jocosus is a species of cobweb spider in the family Theridiidae. The species was described by Gertsch & Davis in 1936. It occurs in the United States and Mexico, representing a relatively restricted North American distribution within its genus.
Chrysso
Chrysso is a genus of comb-footed spiders (Theridiidae) first described by Octavius Pickard-Cambridge in 1882. The genus currently contains approximately 64 species distributed primarily in the Americas and Asia, with some species exhibiting wide geographic ranges. Many species display striking and variable coloration, with some capable of rapid color change when disturbed. The genus has undergone recent taxonomic revision, with several former species transferred to the related genera Megama, Meotipa, and Physcoa.
Chrysso albomaculata
Chrysso albomaculata is a species of comb-footed spider in the family Theridiidae, first described by O. Pickard-Cambridge in 1882. The species is documented from the United States, Caribbean islands, and Brazil. It belongs to a genus of small spiders often associated with leaf litter and vegetation in tropical and subtropical habitats. As with many Theridiidae, detailed natural history information remains limited.
Coleosoma
Coleosoma is a genus of comb-footed spiders in the family Theridiidae, established by O. Pickard-Cambridge in 1882. The genus comprises ten currently recognized species with a cosmopolitan distribution. Taxonomic revision has been ongoing, with several species transferred to other genera and numerous synonymies established. The genus includes both native and introduced species, with C. octomaculatum documented as established in New Zealand through anthropogenic introduction.
Coleosoma acutiventer
Coleosoma acutiventer is a species of cobweb spider in the family Theridiidae. It has been recorded across a broad geographic range spanning from the United States through Central America to Argentina. The species was originally described as Achaea acutiventer by Keyserling in 1884. As a theridiid spider, it constructs irregular, tangled webs for prey capture.
Coleosoma floridanum
Coleosoma floridanum is a small cobweb spider in the family Theridiidae. The species has a broad native distribution across the Americas and has been introduced to multiple regions worldwide, including Europe, West Africa, and Pacific islands. It builds irregular, tangled webs characteristic of its family.
Crustulina altera
cobweb spider
Crustulina altera is a small species of cobweb spider in the family Theridiidae, first described by Gertsch and Archer in 1942. It is known from the United States and Jamaica. Like other members of its genus, it constructs irregular, tangled webs typical of theridiid spiders. Very little has been published about the specific biology or ecology of this species.
Crustulina sticta
Brownblack Cobweb Weaver
Crustulina sticta is a small cobweb spider in the family Theridiidae, commonly known as the Brownblack Cobweb Weaver. It has a broad distribution across the Northern Hemisphere, occurring in North America, Europe, and Asia. The species is part of a genus closely related to Steatoda, which includes spiders frequently mistaken for black widows. Available information on its biology is limited compared to better-studied relatives.
Dipoena
tangle-web spiders
Dipoena is a genus of tangle-web spiders (family Theridiidae) containing approximately 162 species distributed worldwide. The genus was established by Tamerlan Thorell in 1869. Males are distinguished by a characteristically high, cylindrical carapace often bearing grooves or depressions on the dorsum, while female carapaces are rarely modified though sometimes elevated. Species occur across Asia, Central America, North America, Africa, the Caribbean, Europe, South America, Australia, and Pacific islands including Vanuatu.
Dipoena dorsata
Dipoena dorsata is a species of cobweb spider in the family Theridiidae, first described by Muma in 1944. It has been recorded across a broad geographic range from the United States to Paraguay, spanning North, Central, and South America. As a member of the genus Dipoena, it constructs irregular, tangled webs typical of theridiid spiders. Specific details regarding its biology, ecology, and behavior remain poorly documented in the scientific literature.
Dipoena malkini
Dipoena malkini is a species of cobweb spider in the family Theridiidae, first described by Levi in 1953. It is a small spider known from the United States. Like other members of the genus Dipoena, it constructs irregular, tangled webs characteristic of theridiid spiders. The species remains poorly documented with limited observational records.
Dipoena washougalia
Dipoena washougalia is a species of cobweb spider in the family Theridiidae, first described by Levi in 1953. It is known from the United States, with records primarily from the Pacific Northwest region. The genus Dipoena comprises small spiders that construct tangled, irregular webs. Information on this particular species remains limited.
Emertonella
Emertonella is a genus of cobweb spiders in the family Theridiidae, subfamily Hadrotarsinae, first described by E. B. Bryant in 1945. The genus was re-delimited in 2024 based on male palpal morphology, transferring approximately 30 species from the genus Euryopis. It now contains species distributed across Africa, Asia, Europe, North and South America, and New Guinea.
spidercobweb-spiderTheridiidaeHadrotarsinaeant-predator-subfamilyre-delimited-genuscosmopolitan-distributionmale-palpal-morphologytaxonomyEuryopis-transferChinaHenan-Provinceforest-habitatagricultural-habitatJuly-collectionelevation-70-1340mBryant-19452024-revisionPMC12964056ZooKeys-1270genus-levelAraneaeArachnidacomb-footed-spiderEnoplognatha intrepida
Enoplognatha intrepida is a cobweb spider in the family Theridiidae, characterized by its membership in the infraorder Araneomorphae. The species has a notably disjunct distribution spanning North America (USA, Canada, Greenland) and East Asia (Korea). It is one of several species in the genus Enoplognatha, which includes the well-studied and polymorphic E. ovata.
Enoplognatha latimana
Scarce candy-striped spider
Enoplognatha latimana is a cobweb spider in the family Theridiidae, described by Hippa & Oksala in 1982. It belongs to a genus noted for polymorphic coloration, though specific appearance details for this species are not well documented. The species has been recorded across a broad Palearctic range and has been introduced to Canada. A 2024 study documented the first known Wolbachia infection in this species, representing supergroup A bacteria in a specimen from north-western Poland.
Enoplognatha marmorata
marbled cobweb spider
A species of cobweb spider in the family Theridiidae, native to the Holarctic region. It constructs tangled, irregular webs in outdoor vegetation rather than in buildings. The species shows considerable color variation, with individuals ranging from pale to dark with marbled or striped abdominal patterns.
Episinus
Square-ended Cobweb Spiders
Episinus is a genus of comb-footed spiders in the family Theridiidae, first described by Walckenaer in 1809. The genus includes approximately 64 described species distributed across Asia, Africa, and the Americas, with 16 species recorded from China. These small spiders are known for their highly reduced, H- or Y-shaped webs constructed near ground level in low vegetation. Several species have conservation significance, including the Tree H-weaver (Episinus maculipes) which is Red Data Book listed in the UK.
Episinus amoenus
cobweb spider
Episinus amoenus is a species of cobweb spider in the family Theridiidae, first described by Banks in 1911. It is found in the United States and Mexico. The species belongs to the genus Episinus, which is characterized by its distinctive web-building behavior and morphology.
Euryopis argentea
Silver Cobweb Weaver
Euryopis argentea is a small cobweb spider in the family Theridiidae, first described by Emerton in 1882. It belongs to the subfamily Hadrotarsinae, a group distinguished by their unique hunting behavior. Unlike typical theridiids that construct tangled prey-catching webs, Euryopis species are active ant predators that use silk in a specialized ambush technique. The species has been recorded from the United States, Canada, and Russia (Kamchatka).
Euryopis californica
Euryopis californica is a small cobweb spider in the family Theridiidae, notable for its highly specialized ant-hunting behavior. Unlike most theridiids that construct tangled webs to capture prey, this species is an active predator that specifically targets harvester ants. It has been documented as a predator of Veromessor pergandei, employing unique hunting tactics to overcome the formidable defenses of these aggressive ants. The species occurs in the United States and Mexico.
Euryopis formosa
Euryopis formosa is a species of cobweb spider in the family Theridiidae, first described by Banks in 1908. It belongs to the genus Euryopis, a group of small ant-hunting spiders that exhibit unusual behavioral traits for their family. The species is found in the United States and Canada. Like other members of its genus, it does not construct prey-catching webs but instead employs active hunting strategies targeting ants.
Euryopis funebris
Euryopis funebris is a small cobweb spider in the family Theridiidae, subfamily Hadrotarsinae. It is native to North America and has been introduced to South Africa. Unlike typical theridiids that build tangled webs, this species is an active ant-hunting specialist that uses silk to immobilize prey rather than construct capture webs.
Euryopis quinquemaculata
Five-spotted ant-hunting spider
Euryopis quinquemaculata is a small cobweb spider in the family Theridiidae, placed in the subfamily Hadrotarsinae. Unlike typical theridiids that construct tangled webs to catch prey, this species is an active ant specialist that hunts without building prey-capturing webs. The species name refers to the five-spotted abdominal pattern characteristic of this and related Euryopis species. It occurs in the United States, where it inhabits areas with high ant activity.
Euryopis tavara
Euryopis tavara is a small cobweb spider in the family Theridiidae, subfamily Hadrotarsinae. Unlike most theridiids, it does not construct prey-catching webs. The species is known from the United States and shares the genus-wide trait of specialized ant predation. It is one of approximately twenty Euryopis species recorded in North America north of Mexico.
Euryopis texana
Euryopis texana is a small cobweb spider in the family Theridiidae, subfamily Hadrotarsinae. It belongs to a genus of ant-specialist predators that hunt without building prey-catching webs. The species occurs in the United States and Mexico. Like other Euryopis, it likely employs a distinctive hunting strategy of ambushing ants and immobilizing them with silk before delivering a venomous bite.
Flexamia huroni
Huron River Leafhopper
Flexamia huroni is a leafhopper species in the family Cicadellidae, described by Bess & Hamilton in 1999. It belongs to the genus Flexamia, a group of leafhoppers known for their specialized host plant associations with grasses. The species is named after the Huron River in Michigan, where it was first collected. Like other members of the genus, it likely exhibits strong ecological dependence on specific grass host plants.
leafhoppercicadellidaedeltocephalinaeparalimniniflexamiagrass-specialistmichigan-endemicauchenorrhynchahemipterainsectaarthropodaanimaliatrue-bugplanthopper-relative1999-descriptionbesshamiltonhuronihuron-riverusanorth-americagrassland-insecthost-specificpoorly-knownrareuncommondata-deficientgbifcatalogue-of-lifencbiinaturalisttaxonspeciesacceptedhexapodacicadomorphaclypeatamembracoideaparalimninaflexamia-huronibess-&-hamilton1999exact-matchaccepted-namecanonical-namescientific-nameauthorshiprankstatusmatchedtaxonomyclassificationeukaryotametazoadistributionmichiganobservations0wikipedianonepreferred-common-namehuron-river-leafhoppertrue-bugsgroupkingdomphylumclassorderfamilygenusauthorityiptintegrated-publishing-toolkitbiodiversity-data-journalzookeysnature-conservationcomparative-cytogeneticsopen-accessopen-accessjournalpublicationdatasetspecimentypenomenclatural-typeherbariumuniversity-of-granadaspainfungilichensagaricalescortinariusantonio-ortegamediterraneanfranceitalyimage-collectioncolección-de-imágenes-de-los-tipos-nomenclaturales-de-hongoslíquenesmusgos-y-algasgdagdacvizosoquesada2015doi10.3897bdj3e5204new-speciesnew-jersey-pine-barrensmuhlenbergia-torreyanapinebarren-smokegrassthreatened-speciesandrew-hicksmuseum-of-natural-historyuniversity-of-coloradogerry-moorenatural-resources-conservation-servicegreensboronculi-lorimerbrooklyn-botanic-gardenf.-whitcombirobert-whitcombmicrobiologyornithologyecologyhost-plantwarming-climatehuman-activitieszookeys-51169-79zookeys.511.9572roundwormnematodeantarcticamblydorylaimus-isokaryonipararhyssocolpus-paradoxusbulgariascanning-electron-microscopysemmaritime-antarcticantarctic-islandslip-regionspearvulvapostembryonic-developmentmolecular-analysesdorylaimidaelshishkalazarovaradoslavovhristovpeneva25-68zookeys.511.9793anidiv2bulgarian-academy-of-sciencesnational-scientific-fundoctocoralokinawajapannanipora-kamurailiving-fossilblue-coralhelioporaaragonite-calcium-carbonateskeletonscleractinianssoft-coralheliporacealithotelestidaeepiphaxumdeep-seashallow-coral-reefzamami-islandnational-parkmiyazakireimer1-23zookeys.511.9432non-biting-midgechironomusch.-bernensisnorth-caucasusrussiacaucasian-populationseuropesiberiakaryotypemorphologymouthpartslarvaechromosomegenotypic-combinationsmineralizationeutrophicationkarmokovpolukonovasinichkinatembotov-institute-of-ecology-of-mountain-territoriessaratov-state-medical-universitycomparative-cytogenetics-9281-297compcytogen.v9i3.4519sea-turtlerescue-centrefirst-aid-stationloggerheadgreen-turtlecaretta-carettachelonia-mydasbycatchmortalitygreecemigrationsexual-maturityullmannstachowitschuit-the-arctic-university-of-norwaynature-conservation-1045-69natureconservation.10.4890regional-activity-centre-for-specially-protected-areasporcupinecoendou-ichilluslower-urubambaperucanopy-bridgepipelinenatural-gasarborealcamera-trapdwarf-porcupineiquitos770ggregorylundezamora-mezacarrasco-ruedarepsol-exploración-perúzookeys-509109-121zookeys.509.9821antprionopeltamadagascarseychellessubterraneanleaf-litterdracula-anthemolymphlarval-hemolymph-feedingoophagymadagascar-biodiversity-centeroversonfisherzookeys-507115-150zookeys.507.9303itobillenmasukospideranelosimussubsocialcobweb-spidertheridiidaedeforestationbiodiversity-hotspotagnarssonuniversity-of-vermontsmithsonian-national-museum-of-natural-historywallacehuxleybuffonhookerlamarckdarwinmoramoraeriophyoid-miteacarixinjiangchinarosaceaeparacolomerusgallji-wei-liwangxuezhangzookeys-50897-111zookeys.508.8940shihezi-universitygrasshopperwyomingmelanoplusmelanoplinaeacrididaetetrigidaegomphocerniaeoedipodinaecyrtacanthacridinaedistribution-atlasfield-guidewgiswyoming-grasshopper-information-systemkeycapinerasechristhebardhelferscudderblatchleythomassayharrisdegeerbrunersaussuregirarddodgewalkerfieberfabriciusservillemcneilltinkhamburmeisterhaldemanbig-horn-mountainsblack-hillsgladstonindigensinfantilisdodgeioregonensismarshalliyellowstone-national-parksagebrushpineelevationshortgrass-prairiemixedgrass-prairieforbgrasseconomic-damagerangelandbenefitoverwinteregghatchadultlate-summeraugustoctoberjunelife-cyclefood-habitsizecollectionsurveyunderreportedcommonendemicrestricted-rangeforest-openinggrassymoderate-elevationlargersmallereastwestunited-statesamericanorthsouthcentralrangeextentlimitedrestrictedabundantpopulationdensityoccurrencepresenceabsencehabitatenvironmentconditionaltitudetopographyterrainvegetationplantshrubtreeforestopeningmeadowprairiesteppesavannawoodlanddrawslopeaspectsoilsubstratemoisturetemperatureclimateweatherseasonphenologytimingactivitynymphemergemoltdevelopgrowreproducemateovipositdiegenerationvoltinismunivoltinebivoltinemultivoltinesemivoltinediapauseaestivationhibernationdispersalmovementbehaviorhabitactionfeedingdietfoodhostassociationrelationshipinteractionspecialistgeneralistmonophagyoligophagypolyphagyherbivoredetritivorepredatorparasitoidscavengereconomic-importancepestbeneficialneutraldamagecontrolmanagementconservationthreatenedendangeredvulnerablesecureunknownglobal-biodiversity-information-facilityesbiodiversity-image-portalspanish-collectionstype-specimenlichenantarcticabernensisliyellowstoneHentziectypus globosus
Fingered Cobweaver
Hentziectypus globosus is a species of cobweb spider in the family Theridiidae, commonly known as the Fingered Cobweaver. It is a small spider native to North America. As a member of Theridiidae, it constructs irregular, tangled webs rather than organized orb webs. The species was first described by Nicholas Marcellus Hentz in 1850.
Meotipa pulcherrima
Meotipa pulcherrima is a cobweb spider (family Theridiidae) native to Tropical Africa that has established populations across multiple continents through human-mediated introduction. The species occupies savanna and thicket biomes at moderate elevations and constructs tangled webs in vegetation. It is listed as Least Concern in South Africa due to its broad distribution.
Neopisinus
Neopisinus is a genus of comb-footed spiders in the family Theridiidae, established in 2011 to accommodate species previously placed in other genera. The genus contains nine species distributed across the Americas, from the southern United States through Central America and the Caribbean to South America. Two species, N. fiapo and N. urucu, were described as new in the original genus description. The type species is Neopisinus fiapo.
Neopisinus cognatus
Neopisinus cognatus is a species of cobweb spider (family Theridiidae) described by O. Pickard-Cambridge in 1893. It belongs to a genus of small theridiid spiders found in the Americas. The species has been documented across a broad geographic range spanning from the southern United States through Central America to South America, including the Caribbean region.
Neospintharus
Neospintharus is a genus of comb-footed spiders in the family Theridiidae, subfamily Argyrodinae. First described by Exline in 1950, it was synonymized with Argyrodes in 1962 but revalidated in 2004. Phylogenetic studies confirm it as sister group to Rhomphaea within monophyletic Argyrodinae. The genus comprises free-living species that are not kleptoparasitic, distinguishing them from other Argyrodinae genera.
Neottiura
Neottiura Cobweb Spiders
Neottiura is a genus of comb-footed spiders (family Theridiidae) first described by Anton Menge in 1868. The genus contains six species and one subspecies distributed across Asia, Europe, North America, and North Africa. Members are small cobweb spiders that construct irregular, tangled webs. The type species, Neottiura bimaculata, has the widest distribution, spanning from North America across Eurasia to Japan.
Neottiura bimaculata
Neottiura bimaculata is a species of cobweb spider in the family Theridiidae. It has a broad distribution spanning North America, Europe, Turkey, the Caucasus, Russia (Siberia), Central Asia, China, and Japan. The species was first described by Linnaeus in 1767 under the name Aranea bimaculata. Two subspecies are recognized: N. b. bimaculata and N. b. pellucida.
Nesticodes rufipes
Red House Spider
Nesticodes rufipes, commonly known as the Red House Spider, is a cobweb spider in the family Theridiidae and the sole species in its genus. It has been introduced globally and is found on multiple continents including North America, South America, and oceanic islands. The species has been studied extensively for its predatory behavior, exhibiting a type II functional response to prey density. Research indicates that habitat complexity significantly affects its predation efficiency, with reduced capture rates in more complex environments due to prey refuge availability.
Oxyrrhexis
Oxyrrhexis is a genus of ichneumon wasps in the subfamily Pimplinae, tribe Ephialtini, belonging to the Polysphincta genus-group. The genus comprises four described species worldwide. All species are koinobiont ectoparasitoids specialized in attacking spiders, primarily of the family Theridiidae, though one record documents parasitism of a titanoecid spider. The genus was first recorded from Egypt in 2017.
Parasteatoda tabulata
Wandering House Cobweaver
Parasteatoda tabulata is a cobweb spider in the family Theridiidae, first described by H. W. Levi in 1980. It is native to tropical Asia but has been introduced to North America, Europe, and temperate Asia including China, Korea, and Japan. The species belongs to a genus closely related to the Common House Spider (Parasteatoda tepidariorum) and shares similar web-building habits.
Phoroncidia
Mushroom Comb-footed Spiders, cob-web spiders
Phoroncidia is a genus of comb-footed spiders in the family Theridiidae, first described by J. O. Westwood in 1835. The genus contains approximately 83 species distributed worldwide. Members are characterized by heavily sclerotized, often leathery abdomens with distinctive sculpturing including folds, humps, spines, or tubercles. They are commonly known as Mushroom Comb-footed Spiders.
Phoroncidia americana
Phoroncidia americana is a cobweb spider in the family Theridiidae, first described by Emerton in 1882. It occurs in the United States, Canada, Cuba, and Jamaica. Like other members of its genus, it constructs irregular, three-dimensional cobwebs. The species is part of a genus known for small-bodied spiders with reduced web architecture compared to other theridiids.
Phylloneta
Phylloneta is a small genus of comb-footed spiders (family Theridiidae) containing three species and two subspecies with a Holarctic distribution. The genus was elevated from subgenus status in 2008, having formerly been considered part of Allotheridion. Species include P. impressa, P. pictipes, and P. sisyphia (with subspecies P. s. foliifera and P. s. torandae). The type species, P. pictipes, was originally described in 1884.