Theridiid
Guides
Anelosimus studiosus
tangle web spider, cobweb spider, social cobweb spider
Anelosimus studiosus is a subsocial tangle web spider in the family Theridiidae, distributed across much of North and South America from temperate to tropical regions. The species exhibits striking social polymorphism, with two distinct behavioral phenotypes: social spiders that live communally in large cooperative colonies, and asocial solitary individuals that defend individual territories. Social colonies involve multiple adult females sharing web maintenance, brood care, and cooperative prey capture without aggression. The frequency of the social phenotype increases at higher latitudes, correlating with colder temperatures where delayed juvenile development and maternal mortality risks favor communal living. Despite behavioral differences, the two phenotypes interbreed freely and produce viable offspring.
Cryptachaea rupicola
Cryptachaea rupicola is a cobweb spider in the family Theridiidae, first described by Emerton in 1882. The species occurs in the United States and Canada. As a member of Theridiidae, it constructs irregular, three-dimensional webs. Very little detailed information about its biology, ecology, or specific habitat requirements has been documented.
Enoplognatha joshua
Enoplognatha joshua is a species of cobweb spider in the family Theridiidae. It was described by Chamberlin and Ivie in 1942. The species is known from the United States and has also been recorded in the Canadian provinces of Alberta and British Columbia. Like other members of the genus Enoplognatha, it constructs tangled, irregular webs characteristic of theridiid spiders.
Enoplognatha ovata
candy-striped spider, common candy-striped spider, polymorphic spider
Enoplognatha ovata is a small theridiid spider native to Europe and introduced to North America. The species exhibits striking color polymorphism, with three main morphs varying in abdominal pigmentation from plain to striped patterns. Despite its diminutive size (4-7 mm), it is an effective predator capable of capturing prey substantially larger than itself. Females construct tangled webs on the undersides of leaves and demonstrate maternal care by guarding egg sacs and provisioning spiderlings.
Euryopis mulaiki
Euryopis mulaiki is a minute cobweb spider (Theridiidae) in the subfamily Hadrotarsinae, distinguished by its unusual hunting behavior. Unlike web-building relatives, this species is an active ant predator that immobilizes prey by flinging silk rather than constructing capture webs. Adults are exceptionally small, with body lengths of 1.3–4.7 mm, and exhibit a characteristic sub-triangular abdominal shape with bold color patterns. The species was described by Levi in 1954 and occurs in the southwestern United States and Mexico.
Phylloneta impressa
Forest Cobweb Weaver
Phylloneta impressa is a small comb-footed spider (Theridiidae) with a Holarctic distribution. Males measure 2.5–5.5 mm and females 3.5–5.5 mm. The species constructs tangle webs beneath retreats on vegetation and has been documented in agricultural settings including rape fields. It is closely related to and frequently confused with Phylloneta sisyphia.
Platnickina
Platnick's Cobweb Spiders
Platnickina is a genus of cobweb spiders (Theridiidae) established in 2008 and named in honor of arachnologist Norman Platnick. The genus is cosmopolitan, excluding Oceania, with fifteen recognized species as of 2025. European species exhibit distinctive bright yellow coloration with black mottling. The genus can be distinguished from other theridiids by specific morphological traits including trichobothria on the metatarsi of the third leg pair.
Rhomphaea projiciens
Rhomphaea projiciens is a species of cobweb spider in the family Theridiidae, first described by O. Pickard-Cambridge in 1896. It exhibits a broad native range across the Americas, from the United States south to Argentina, and has established introduced populations in India. The species belongs to a genus characterized by unusual body proportions and modified legs. Records indicate presence across multiple Brazilian states and other South American countries.
Steatoda nobilis
Noble False Widow
Steatoda nobilis is a large theridiid spider native to Madeira and the Canary Islands, now established as one of the world's most invasive spider species. It has spread across Europe, North and South America, and other temperate regions, often becoming the dominant spider in urban environments. The species is of moderate medical significance: bites typically cause symptoms similar to bee or wasp stings, though some cases involve more severe reactions including bacterial infections from pathogenic bacteria carried on the spider's body. It constructs strong, irregular cobwebs with concealed tubular retreats and employs an 'attack wrap' hunting strategy to subdue prey.
Thymoites maderae
Thymoites maderae is a species of cobweb spider in the family Theridiidae, first described by Gertsch and Archer in 1942. The species occurs from the United States through Panama. Very little is known about its biology or ecology. Available records suggest it inhabits Middle and North America, though specific habitat associations remain undocumented.