Poisonous Spiders in Tennessee
Few things cause as much fear and anxiety in people as the thought of poisonous spiders. Tennessee is home to many species of spiders; however, only two are poisonous - the black widow and the brown recluse. Both species are found in every Tennessee county.
Below are some useful tips for keeping spiders at bay:
If you suspect that you have a spider bite, contact your primary care physician.
The above information is provided by The University of Tennessee Agricultural Extension Service. For more information about spiders and other subjects, visit the Agricultural Extension Service website.
Brown Recluse Spider
The brown recluse is a shy, retiring spider that does not attack people and usually only bites in response to being injured. This is quite the opposite of what most people think! Most reported bites occur when putting on clothing in which the spider is hiding or rolling on a spider in bed. Most people living in proximity to the spider will never see it, nor be bitten by it.
The brown recluse is a medium-sized spider. The legs span an area roughly the size of a quarter to a half-dollar. The color of the brown recluse ranges from a light yellowish brown to a dark reddish or chocolate brown, but most are light to medium brown. The second pair of legs is always longer than the remaining pair in both the male and female. Three pairs of eyes are arranged in a semicircle. Since most other spiders have eight eyes, this feature alone can eliminate many specimens suspected of being a brown recluse spider.
The most distinguishing characteristic is the violin-shaped marking on the top of the body directly above the legs. The violin-shaped marking is usually much darker than the surrounding areas and may appear lined. Since some other species of spider have a violin-shaped marking, the best identification feature for the brown recluse is a semicircular arrangement of the three pairs of eyes. Contact your county Extension agent to identify a suspected brown recluse spider.
Brown recluse spiders prefer sheltered areas with low moisture levels. In homes, they tend to prefer darkened storage areas in closets, garages, basements, attics and cupboards. Since most brown recluse spiders hibernate in the winter (except for those that live indoors), most bites occur between March and October when humans accidentally disturb their habitat: closets, out-buildings or woodpiles.
For a photo and a publication on the brown recluse spider, click here.
Black Widow Spider
Black widow spiders are very numerous in nearly all parts of the U.S., but cases of reported bites are not common. For the most part, black widows live peacefully in close proximity to humans with little contact. Both the northern and southern black widows are found in Tennessee, with the southern species being the most common. The black widow appears shiny and hairless to the naked eye. The body ranges from a deep glossy black to an occasional dark brown to a reddish brown. The underside of the abdomen has a distinct red or orange hourglass shape. In immature spiders, the color can vary, and the hourglass may be white or missing.
The body of the female adult black widow spider can reach 1 ½ inches with the legs fully extended. Black widow spiders have eight eyes arranged in two rows of four. The males are generally considered harmless and are usually about half the size of females with yellow or red spots or bands on the back or sides.
The black widows prefer closed, dark places such as water meter compartments and crawl spaces, so barriers constructed to inhibit entrance to these areas are of value. Common places where black widow spiders may be found are firewood piles, under boards and furniture, inside boxes, behind and under debris, sheds, barns, well houses and root cellars.
For a photo and a publication on the black widow spider, click here.