Steatoda

Classification

Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Theridiidae
Genus: Steatoda

Pronunciation

How to pronounce Steatoda: //stiːəˈtoʊdə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Rabbit Hutch Spider (Husenkeedderkopp) (Steatoda bipunctata) - Bærum, Norway 2021-09-01 by Ryan Hodnett. Used under a CC BY-SA 4.0 license.

Steatoda.grossa by wikipedia. Used under a CC BY-SA 3.0 license.

Mature male Steatoda bipunctata, Botevgrad, Bulgaria 01 by Dimitǎr Boevski. Used under a CC BY-SA 4.0 license.

Mature male Steatoda bipunctata, Botevgrad, Bulgaria 03 by Dimitǎr Boevski. Used under a CC BY-SA 4.0 license.

Steatoda grossa-False Black Widow (NZAC06001341) by Don Horne. Used under a CC BY 4.0 license.

Steatoda albomaculata 2 by Roman. Used under a CC BY 4.0 license.

Summary

The genus Steatoda includes species commonly known as cupboard spiders or false widows, known for their web-building in sheltered spaces. They possess varying coloration and markings and are prey to various insects. Their bites, while sometimes painful, generally do not require medical attention.

Physical Characteristics

Females: 2.5-11.0 mm; Males: 2.0-7.5 mm. Coloration varies from sandy pale brown to reddish plum to black, often featuring white or beige to orange markings with a characteristic frontal crescent and dorsal line or triangular shapes.

Identification Tips

Species identification is challenging due to similar external appearances within the genus. Many species can have faint or nearly-invisible patterns, complicating habitus-based identification. Look for small white spots of spider droppings beneath their webs, and general body shape.

Habitat

Steatoda spiders prefer dark, sheltered areas such as houses, gardens, sheds, garages, and compost bins.

Distribution

Approximately 20 species in the region, with populations in Southern Canada to central Mexico, across the western US, and various specific localities including California, Florida, and Texas.

Diet

Steatoda prey on other spiders (including true black widows), crickets, ladybugs, cockroaches, and woodlice.

Ecosystem Role

They play a role in controlling pest populations as predators of various insects and other spiders.

Cultural Significance

Commonly known as cupboard spiders, they are often confused with widow spiders, particularly due to their appearance, leading to misinformation about their venomous nature.

Health Concerns

Some species, like S. grossa and S. nobilis, have bites reported to cause pain and mild symptoms but are not life-threatening. Total cases are rare, and no bites have required medical treatment. Symptoms can include pain, nausea, headache, and lethargy, subsiding within 1 to 60 hours.

Similar Taxa

Latrodectus

Misconceptions

Often mistaken for widow spiders, however, they are less harmful and many do not resemble black widows at all. Misunderstanding of their bite severity is common due to sensationalized reports in media.