Steatoda borealis
This record describes Steatoda borealis (species). Recorded family: Theridiidae. Recorded order: Araneae.
Identification and Appearance
The abdomen is reddish brown with a lighter T shaped mark at the front end. The underside of the abdomen is also considerably lighter than the upper side. Note that several other species in the genus (including bipunctata, grandis, hespera, and possibly mexicana) can have nearly identical markings. This species is native to North America. Both males and females have a rough surface with ridges on the abdomen front that forms a stridulating organ. The spider can make sounds by rubbing this against the carapace.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Arachnida
- Order
- Araneae (Spiders)
- Family
- Theridiidae (Cobweb Spiders)
- Genus
- Steatoda
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Habitat
Most likely to be found under bark and stones, in rock crevices, on bridges and in outbuildings and unfinished basements.
Geographic Range
East of the Rocky Mountains in the United States to Alaska. Typically in northern states, but has recently been found in southern ones over the past 50 years or so.
Diet and Behavior
Life History
Click on the image below to see the life cycle.
Additional species information
Species notes from the sources
Etymology: Latin for "northern"
About Spiders: the wider group
Order-level background for Araneae, the group containing Steatoda borealis. Species-specific details appear above.
Group overview
As of 2023, 51,673 spider species in 136 families have been recorded, though an estimated 150,000 species exist. Spiders rank 7th in total species diversity among all organism orders. Only 0.5% of spider species pose any risk to human health.
Ecological role of the group
Spider venom contains complex peptides with diverse pharmacological activities, making them valuable for drug development research. Spiders produce up to 7 types of silk from specialized glands. Spider silk genes have been inserted into mammals and plants for biotech applications.
Economic and practical significance of the group
The global spider community kills an estimated 400-800 million tons of prey annually (2017 study). Spiders provide billions of dollars in natural pest control for agriculture. Spider silk is 5× stronger than steel of the same diameter, driving a biomaterials research industry.
Recorded sources for this group: World Spider Catalog, PNAS, Nature, ScienceDirect. Imported estimates may describe particular regions or reporting periods.
Photos of Steatoda borealis (5)
Photo credits: Contributed by Chris Wirth; Additional contributions by Lynette Elliott , Chuck Entz , marcie oconnor , Mandy Howe , Marci Hess , chuuuuung
Frequently Asked Questions About Steatoda borealis
What is Steatoda borealis?
Steatoda borealis is a species in the family Theridiidae, within the order Araneae.
How big is Steatoda borealis?
Females reaching a maximum size of about 7 mm
How do you identify Steatoda borealis?
The abdomen is reddish brown with a lighter T shaped mark at the front end. The underside of the abdomen is also considerably lighter than the upper side. Note that several other species in the genus (including bipunctata, grandis, hespera, and possibly mexicana) can have nearly identical markings.
Where is Steatoda borealis found?
| Feature | Details |
|---|---|
| Habitat | Most likely to be found under bark and stones, in rock crevices, on bridges and in outbuildings and unfinished basements. |
| Range | East of the Rocky Mountains in the United States to Alaska. Typically in northern states, but has recently been found in southern ones over the past 50 years or so. |
What is the life cycle of a Steatoda borealis?
Click on the image below to see the life cycle.