Black widow spiders are small arachnids but are one of the deadliest spiders in the world. The spiders derive their name from the popular assertion that the female black widow spider feeds on the male spiders after mating. Black widow spiders can be found on every continent except Antarctica and mainly inhabit warmer regions.
The black widow spiders are popular for the red hourglass shape under their abdomen and are typically shiny black or dark brown in color. Some possess a pair of red spots on their back while others do not have markings at all. The male spider has various red or red and white marks on the upper part of the abdomen while the female does not have any bright markings. The black widow spider can grow up to 0.39 inches in size while some female measure about 0.51 inches in body length.
They produce unusually potent venom that causes a condition known as latrodectism. The female spiders have large venom glands and their bite is particularly harmful to large animals including humans. However, the spiders rarely bite and bites are rarely fatal. The bites only occur when they cannot escape danger. Symptoms of bites include increased blood pressure, fever, nausea, and sweating. These symptoms may last 3-7 days or persist for more than one week. Medication is recommended as soon as possible to relieve the victim of the pain.
The black widow spiders inhabit mainly the warm regions of the world. They are found in marginal land areas with sparse vegetation, hollow logs, and stumps. The spiders are rarely found indoors but may enter human houses on items brought inside. Indoors, the black widow spider prefers cluttered areas such as garages, crawl space, and basements. Once they settle in these areas, the black widow spiders spin irregular webs which are mainly built at night and near the ground level. The spiders hang upside down on the web once completed.
Distribution and Range
The black widow spiders can be found in all the continents except Antarctica. In North America, the black widow spiders can be found in the United States and Canada. In the US, they are found in all the four southwestern deserts (Great Basin, Sonoran, Chihuahuan, and Mojave). They can also be found in Florida and Texas. In Canada, there are two species of black widow spiders. The western back widow spiders inhabit part of the Okanagan Valley of British Columbia through to Manitoba where they are restricted to the southern border with the US. The northern black widow spiders are commonly found in eastern and southern Ontario. In Europe, the black widow spider is mainly found along the Mediterranean while in Africa the spider can be found on Cape Verde Island and southern Africa.
The black widow spider mainly feeds on insects such as mosquito, flies, grasshoppers, and beetles. The spider mainly hangs upside down at the center of the web and waits for the insect to get stuck. Before the insect can free itself from the web, the spider rushes and injects it with the venom and wraps it in silk. Before feeding, the black widow spider pulses a digestive juice over the insect which liquefies, allowing for capillary action.