Steatoda grossa  (THERIDIIDAE)

Along with S. nobilis and S. bipunctata, Steatoda grossa is one of the three species of this family that is relatively common, especially in the south of the UK. Despite its name, with a female body length of up to 10 mm it is significantly smaller than S. nobilis at 14 mm. While the other common species of this family are found regulary both in houses and around them, S. grossa much prefers to stay indoors. The features in the micrographs should be compared with those of Steatoda bipunctata and Steatoda nobilis.

Close-up of the eyes of Steatoda grossa The bottom end of the chelicerae of Steatoda grossa, viewed from the side nearest the mouthparts. The opening through which venom is injected into the prey is just visible in the tip of the left fang. Left Pedipalp (male sexual organ) of Steatoda grossa

Epigyne (female sexual organ) of Steatoda grossa Spinnerets of Steatoda grossa Tarsal claw of Steatoda grossa. This is a rather poor micrograph, but illustrates similar characteristics to those of the other Steatoda species illustrated on this website.