Black widow spider

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.