Arachnids of North Carolina
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View Theridiidae Members: NC Records

Steatoda grossa - False black widow



Female typical form with dimples

Male

Female spotted form
Taxonomy
Order: ARANEAEInfraorder: AraneomorphaeFamily: Theridiidae                                                                                 
Comments: Can be found in mid-20th Century literature as Teutana grossa.
Identification
Online Description/Photos: BugGuide, Google Images, iNaturalist, Wikipedia
Comments: While bearing the American Arachnological Society's recognized common name "false black widow," many specimens are not black, but a purplish-brown, with white markings. The black individuals have no red markings, unlike the northern and southern black widows that occur in NC (Latrodectus varioulus and L. mactans, respectively). Also unlike Latrodectus spp., S. grossa's abdomen is oval, rather than teardrop-shaped. Females are readily distinguished from other NC Steatoda by examination of the epigynum (see comparison figure).
Total Length: Females 6-10mm; males 5.6-7mmAdult ID: identifiable by photo of specific features and/or supplementary info
Structural photos
Distribution in North Carolina
Comments: Typically found in coastal states.
County Map: Clicking on a county returns the records for the species in that county.
Adult phenology:
 High Mountains (HM) ≥ 4,000 ft.
 Low Mountains (LM) < 4,000 ft.
 Piedmont (Pd)
 Coastal Plain (CP)

Click on graph to enlarge
Habitats and Life History
Habitats: in/on buildings, other sheltered locations
Observation Methods:
Abundance/Frequency:
Silk / Web: Typical tangled cobweb spider webbing in protected locations, and usually with numerous gumfoot lines.
Prey: As are many theridiid spiders, S. grossa is an opportunist, and has been noted to feed on widow spiders.
Status in North Carolina
Natural Heritage Program Status:
Natural Heritage Program Ranks:
State Protection:
Comments:

Photo Gallery for Steatoda grossa - False black widow

Recorded by: Brian Bockhahn
Durham Co.
Comment:
Recorded by: Brian Bockhahn
Durham Co.
Comment:
Recorded by: Donald ZEPP
Johnston Co.
Comment: Observed male 2 days before collecting him from female's web. He had two palps at that time, but his right palp was missing when he was collected.
Recorded by: Donald ZEPP
Johnston Co.
Comment: Observed male 2 days before collecting him from female's web. He had two palps at that time, but his right palp was missing when he was collected.
Recorded by: R. Newman
Carteret Co.
Comment: FOMA
Recorded by: R. Newman
Carteret Co.
Comment: FOMA
Recorded by: Donald ZEPP
Johnston Co.
Comment: Hiding in gap of door frame near flocculent egg case in web.
Recorded by: Donald ZEPP
Johnston Co.
Comment: Hiding in gap of door frame near flocculent egg case in web.
Recorded by: Donald ZEPP
Johnston Co.
Comment: Hiding in gap of door frame near flocculent egg case in web.
Recorded by: Newman,Randy
Carteret Co.
Comment: FOMA - Fort
Recorded by: Newman,Randy
Carteret Co.
Comment: FOMA - Fort
Recorded by: Chris Helms
Columbus Co.
Comment: LAWA - Under carport trash can at Supt. residence.
Recorded by: Chris Helms
Columbus Co.
Comment: LAWA - Under carport trash can at Supt. residence.
Recorded by: j.wyche
Gates Co.
Comment: MEMI - in wood pile at 358 Millpond Rd.
Recorded by: j.wyche
Gates Co.
Comment: MEMI - in wood pile at 358 Millpond Rd.
Recorded by: Brian Bockhahn
Polk Co.
Comment:
Recorded by: Brian Bockhahn
Durham Co.
Comment:
Recorded by: Brian Bockhahn
Orange Co.
Comment: