latrodectus-geometricus-e28093-also-known-as-the-brown-widowSize

Female: about 12-16 mm (> 0.5 inch) long (body length only, not including legs)
Male: much smaller, 6-8 mm (about half the body length of a female) but with longer legs.

Identification

The brown widow is highly variable in color. It may be almost white to almost black. Typically, it is a light to medium brown, with an orange-to-yellow hourglass marking on the underside of the abdomen; the coloration of the hourglass often is a good indication of this species. The leg segments are banded, with one half of each segment lighter in color than the other half. The back often has a row of white spots (rarely orange or light blue), and there are a few white stripes on each side. Darker individuals lack these markings and are difficult to distinguish from black widows.

If an eggsac is present, this is the best identifying characteristic. Brown widow eggsacs are tan, spherical, and have many small tufts of silk sticking out from them. They resemble a ’sandspur.’ The other widows make white, smooth eggsacs that tend to be pear-shaped.

Range

World wide in the tropical zone. It was introduced in Florida and has since been observed moving north through Georgia, and into South Carolina; it has also been officially recorded in California, Alabama, Mississippi, and Texas.

Habitat

Found around buildings in tropical climates. However, it is an introduced species and is the most human-adapted of the species occurring in the South Eastern US. Its webs may occur anywhere there is sufficient space to make one. It may be extremely abundant on houses and other man-made structures (e.g., barns, fences, guard rails, bridges). It reproduces frequently and disperses rapidly, making it nearly impossible to control.

Food

Typically insects, but has been observed killing small toads that have gotten caught in its web (but no confirmed record of eating the toad).

Life Cycle

Females can live up to 3 years, while the males only live from 6 months to 1 year. The Brown Widow is the most actively reproducing widow species, producing up to 5000 young per female per season.

Remarks

Widow Bites:

NOTE: It is recognized that this particular species of widow is most likely not medically significant (not an immediate medical concern to those who are bitten). (Net Ref (4)) The brown widow produces clinical effects similar to that of the black widow but the typical symptoms and signs being milder and tending to be restricted to the bite site and surrounding tissues. (Print Ref 1)

Brown widow spiders usually curl up into a ball, and drop to the ground as a primary defense. It is highly recommended that people leave this spider alone; observe, but don’t touch.

Males and immatures do not bite. The brown widow is an extremely timid spider which has rarely been reported to bite.

Precautions:

Be very careful when working around areas where widow spiders may be established. Take proper precautions-wear gloves and pay attention to where you are working. The reaction to a widow bite can be painful, and the victim should go to the doctor immediately for treatment.