Black Widow Spider

Return to Pest Gallery Black Widow Spiders

The black widow spider and northern widow spider are present in throughout the southeast United States. Both species can be aggressive, and their bites are venomous. Black Widow spider bites are generally not fatal, however their bites should be treated by trained medical personnel. The widow spiders are considered to be the most venomous spiders in North America, and they should be given due respect.

Adult black widow spiders have shiny, jet black, rounded abdomen with two red or yellow triangles on the underside of their body. These colored markings form the characteristic hourglass marking. Widow spiders are usually about 1/2" long, not including the legs which are about 1-1/2" inches when legs are spread. Adult males are harmless, about half the female's size, with smaller bodies, longer legs and usually have yellow and red bands and spots over their back. Newly hatched spiderlings are predominately white or yellowish-white, gradually acquiring more black and varying amounts of red and white. True juvenile widow spiders are harmless.

Widow spiders spin webs of coarse silk in dark places, usually outdoors. Webs are usually built near the ground, in trash piles, under or around houses, garages and sheds. The female lays eggs in silken cocoons or sacs which are globular in shape and about 1/2" in diameter. Sacs are white at first, later turning pale brown. About 300 to 400 eggs per sac is common with 4 to 9 egg sacs produced during a summer. Due to cannibalism, usually only 1 to 12 young survive after the incubation period.

Growth requires 2 to 4 months depending on availability of prey during which the females molt 6 to 8 times and the males 3 to 6 times. Females mature 92 days after egg sac emergence and live about 179 days longer, whereas males mature 71 days after emergence and live 30 days longer. Usually the female eats the male after mating. However, if females are well fed, males can sometimes escape. Females hang belly upward, rarely leaving the web, and feed on a variety of insects caught in their web.

The female black widow is shy and nocturnal in habit. She does not leave her hidden web voluntarily and is completely out of her area when away from the web. Outbreaks of black widows occur erratically. Some years an area may have thousands of widows and the next year they may be gone. Certain kinds of habitats such as sand dune areas may have black widows every year. Alternating warm and cold weather during the winter and spring months are detrimental to survival.

Black Widow Spider Bites

The venom of the black widow spider is considered to be 15 times as toxic as the venom of the prairie rattlesnake. Widow spider bites are rarely fatal because only a small amount of spider toxin is injected during a single bite. The severity of a person's reaction to the bite depends on the area of the body bitten, the victims general health, amount of venom injected, and temperature. The bite feels like a pin prick or is not even felt. At first, there may be only slight local swelling and two faint red spots surrounded by local redness at the bite. Pain becomes intense in 1-3 hours and may continue up to 48 hours. Pain usually progresses from the bitten member up or down the arm or leg, finally localizing in the abdomen and back. The abdominal muscles may become rigid and board-like with severe cramps (resembles appendicitis). There may be pain in the muscles and soles of the feet, and eyelids may become swollen. Other symptoms may be nausea, profuse perspiration, tremors, labored breathing and speech, and vomiting. During this time, a feeble pulse, cold clammy skin, unconsciousness, convulsions and even death may result if the victim does not receive medical attention immediately. Additional complications may occur due to the infection of the bite.

Control of Black Widow Spiders

Killing Black Widow Spiders can be easily accomplished with our pest control services. Regular pest control services are your best bet to kill any spiders in or around your home.

Infestation Prevention can be accomplished by removing piles of lumber or debris around houses, garages, and sheds. Homes should utilize screens on doors and windows, as well as sealing cracks and crevices where spiders can enter the house. A periodic exterior pressure washing to remove webs is advisable.

Please use the following link to learn more about another dangerous spider in Georgia.