Black Widow
Both the black widow spider and northern widow spider are present in Ohio. The black widow spider is found primarily in the southern Ohio counties whereas the northern widow spider is found in the northern Ohio counties. Most occur outdoors and are not aggressive unless confined or disturbed. Females are more likely to bite when guarding an egg sac. Reports indicate that mortality from bites is the result of 1% or less of the cases, usually occurring in very young or very old individuals. With healthy people, recovery is usually complete in 2-5 days. However, this spider is considered the most venomous spider in North America.
Adult black widow spiders have shiny, jet black, rounded, globular abdomens with 2 reddish or yellowish triangles on the underside that form a characteristic hourglass marking. Adult female northern widow spiders are shiny black or brown-black with 2 reddish triangles on the underside, resembling a split hourglass. These spiders are about 1/2 inch long, not including the legs (about 1-1/2 inches when legs are spread). Adult males are harmless, about half the female's size, with smaller bodies, longer legs and usually have yellow and red bands and spots over the back as do the immature stages. Newly hatched spiderlings are predominately white or yellowish-white, gradually acquiring more black and varying amounts of red and white with each molt. Juveniles of both sexes resemble the male and are harmless.