Monday, November 23, 2015
Latrodectus is a genus of spider, in the family Theridiidae, that contains 31 recognized species. The common name widow spiders is sometimes applied to members of the genus due to the behavior of the female of eating the male after mating, although sometimes the males of some species are not eaten after mating, and can go on to fertilize other females.The black widow spiders are perhaps the best-known members of the genus.This spider’s bite is much feared because its venom is reported to be 15 times stronger than a rattlesnake’s. In humans, bites produce muscle aches, nausea, and a paralysis of the diaphragm that can make breathing difficult; however, contrary to popular belief, most people who are bitten suffer no serious damage—let alone death. But bites can be fatal—usually to small children, the elderly, or the infirm. Fortunately, fatalities are fairly rare; the spiders are nonaggressive and bite only in self-defense, such as when someone accidentally sits on them.These spiders spin large webs in which females suspend a cocoon with hundreds of eggs. Spiderlings disperse soon after they leave their eggs, but the web remains. Black widow spiders also use their webs to ensnare their prey, which consists of flies, mosquitoes, grasshoppers, beetles, and caterpillars. Black widows are comb-footed spiders, which means they have bristles on their hind legs that they use to cover their prey with silk once it has been trapped.