Brown Widow Spider

Latrodectus geometricus, family Theridiidae

Identification

Similar to Redback but larger and all brown to black without the upper red stripe. Rarely jet black. Length: Similar to Redback, legs span up to 40mm.

Brown Widow Spider, Theridiidae, Latrodectus geometricus, female

Distribution

Introduced to Australia, presumably during World War II as it is often found near U.S. Air bases. Originally reported from Darwin but in 1987 also reported from Brisbane and later Townsville, Rockhampton and Kingaroy. Strongly associated with human habitation.

In the 1980s and early 1990s, Brown Widows became more common in Brisbane but soon died out quite strongly and are now quite rare.

Web

Fine strong threads. The web is often built in cooler locations than the Redback and may actually build inside offices and around vegetation.

Bite

Strong and painful but not as severe as the Redback. Brown Widow venom is slightly less toxic than Redback venom.

Notes

Breeding in Summer with the potential for year long breeding. The egg sac is prickly, whereas the egg sac of the Redback is a smooth sphere.

Main prey: insects, frogs, lizards and other spiders.

Similar species

Redback and Cupboard Spider.

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