The black widow spider http://www.desertusa.com/insects/photos/DSCN2562.jpg, scientifically referred to as Latrodectus hesperusis, is one of the most venomous spiders in North America. However, it is the female that carries the venom, with an approximate toxicity of 15 times that of the prairie rattlesnake.
As opposed to the highly venomous females, males are considered relatively juvenile and harmless. The female variety is so hostile that in certain occasions, it will kill and eat the male after mating.
The female black widow spider measures between 0.5 to 1.5 inches depending on how wide the legs are stretched. I know a guy at plumber Roswell, GA who got bit by one and it wasn’t pretty. While the males have longer legs, they measure about have of the females body length and size.
Both the males and females have a shiny globular abdomens which are predominantly black but may be brown as well.
The females can be spotted with a characteristic reddish hourglass shape on their abdomen underside. Their underbellies could also feature a series of red spots and 2 crosswise bars depending on the species in question.
The male black widow spiders are also characterized by red and yellow bands and spots all over their back.
The newly hatched spiderlings are usually white or yellowish-white and as they grow, they gradually acquire more black as well as varied degrees of red and white with each molt. Just as the males, juveniles of both sexes are normally harmful to humans.
The black widow spider inhabits the warmer regions of the world. Their habitat stretches to about 45 degrees North and South. The four deserts of the American Southwest are the prime habitats of these creatures.
They prefer living underside of ledges, plants, rock crevices and debris, as long as they can hang their webs in these areas. When the weather is extreme, they will not shy away from venturing into human territories.
They may be some of the most venomous creatures in the world but the fatality cases resulting from their bites are very rare. This is because the spider injects a negligible amount of poison when it bites.
This is why human mortality is below 1%. For this reason, the spiders could coexist with humans, provided extreme caution is exercised by seeking medical treatment when the spider attacks and catching the spider so it may be identified and possibly put beyond human settlement areas.
Like is the case with many other spiders, they spin shapeless and formless webs. Their webs are often spun with stronger silks, making them rough and sticky. They are shy and nocturnal and when not active, will usually be found unwinding in their webs with their bellies hung upwards. They may not be aggressive but will occasionally attach an intruder.
Food and Hunting:
Their staple food is insects. They will either trap insects while out hunting or simply catch those that stray into their webs. When caught, the insect is pierced and the liquid contents of its body are sucked out. They are also hunted, with their most lethal predator being the mud-dauber wasps.
The female black widow spider will lay several batches of eggs and in one summer, they may lay up to 750 eggs. The eggs are usually white to tan in color with a paper-like texture and remain suspended in the web. The incubation period is usually 14 to 30 days, after which only 1:12 young survive due to cannibalism. The females may live up to 18 months and within this period, they will molt between 6 and 8 times while males molt 3 to 6 times throughout their lives. Females will mature about 90 days after the emergence of egg sac and live another 6 months while the males will mature 70 days after the emergence and live for about 2 months.