Latrodectus geometricus

Brown widow females

The brown widow ( Latrodectus geometricus ) is a web spider from the family of cobweb spiders ( Theridiidae ). It belongs to the genus of the Real Widows ( Latrodectus ).

Description

The females of the brown widow have a body length excluding the legs of about 12 to 16 millimeters, the males are having 6 to 8 millimeters significantly smaller, but have longer legs. It has a large phenotypic spectrum of colors. Thus, a brown widow from nearly white to almost black any color, but typically is a light brown color. The color is not only individually different, but also changes in single individuals throughout their lives. Almost black shapes are to be distinguished from the Black Widow hardly. On underside of the body she wears a orange colored, typical for many species Latrodectus drawing in the form of an hourglass. The back is often spotted white, with color variations are also possible here.

The best way to the brown widow of the cocoon she spins around their eggs, identify. The cocoon is made of silk and is spherical in shape, the silk spines forming on the outside. The brown widow is described as very cautious, there are extremely few bites on humans known, even if, as, quite common in Florida and the proximity of man is not afraid.

Dissemination

The brown widow is represented in southern latitudes around the world. Originally it probably comes from South Africa, but it was ( with the exception of Antarctica ) introduced on all continents.

In the U.S., the spider has long been familiar, but has since the mid- 90s, from Florida, spread rapidly in the southeastern states. Individual finds have been also reported to Arizona, Colorado and New Mexico. In Southern California, their distribution now ranges from Los Angeles County to San Diego County and east to Riverside County. In Hawaii, the brown widow was registered in 1939 for the first time and has since spread to all major islands.

In Japan, there was the first backed report on the occurrence of the brown widow in 1995 from the port city of Yokohama. By September 2008 it had spread to 11 Japanese prefectures. 2004, a copy near Pune in India has been found.

The distribution of the spider between the continents is made by container ships. Their rapid spread within a country is due to the transport of goods by trucks. Benefiting it is through the mild winters of recent decades in the northern hemisphere.

Way of life

The females live 3 years, the males live only 8 months or a year. The females feed primarily on insects, but it was also observed that even small toads were eaten, which became entangled in its web.

The species can be found in populated areas around homes, in gardens, in cars and campers. They also colonized plastic garden furniture, flower pots or leaves of bird of paradise flowers. Usually they are found wherever she finds a sheltered place.

Medical importance

The males are harmless, just bite the females, their venom is classified as the Southern Black Widow ( Latrodectus mactans ) and the European black widow ( Latrodectus tredecimguttatus ) as less dangerous, but also it is one of the most effective spider toxins. In general, these spiders take at hazard into a defensive posture, in which they create the limbs closely. Only if they continue to be irritated, they can be aggressive and bite.