and related species: Latrodectus mactans, L. hesperus, L. various, L. geometricus, L. bishopi
Range: Five related species are found in North
America, north of Mexico. The black widow is recognized as three
species, which are very similar in appearance and habitat. These three
widow spiders are the Southern black widow (Latrodectus mactans), the Western black widow (L. hesperus) and the Northern widow (L. variolus). The brown widow (L. geometricus) is found in California, southern Florida and throughout Africa. The red-legged widow (L. bishopi), is limited to southern Florida.
Habitat: Black widow spiders are common around wood
piles, and are frequently encountered when homeowners carry firewood
into the house. They also are found under eaves and in boxes, outdoor
toilets, meter boxes and other unbothered places.
Health risks: The venom, a neurotoxin, is highly
virulent in all the widow spiders. Some report the widow spiders as
being aggressive, but observation shows they are very timid and have no
instinct to bite humans. When disturbed in their webs, widow spiders
attempt to escape rather than attack.
Management: Apply insecticide treatments, such as
Talstar® Professional insecticide so that the chemical contacts spiders in their webs. It can
also be applied for residual control in corners, behind and under
furniture, behind stored items, etc., to prevent establishment of new
spiders.