Often the extension office receives calls from homeowners concerning spiders they have found and whether they are poisonous. There are many species of spiders native to our area, but only two are venomous: the brown recluse and the black widow. However, most spiders are harmless and are actually beneficial because they consume insect pests, like flies and mosquitoes.
Brown recluse spiders are sometimes referred to as “fiddleback” spiders due to the violin-shaped markings on their backs. They are about 1⁄4 to 3⁄4 inch long and prefer to inhabit quiet, undisturbed places such as boxes, under furniture, in attics or in any dry, warm areas. The spider ranges from the central Midwestern states southward to the Gulf of Mexico. In Georgia, they may be found in the western and the northwestern parts of the state.
The brown recluse will only bite when it accidentally comes into contact with human flesh. Those who are bitten by the spider develop a wound that does not heal quickly. The area becomes painful, eventually turning black as the skin tissue starts to die leaving a depression and unsightly scar. Sometimes surgery is required to remove the dead tissue.
Frequently, other skin infections, including methicillin-resistant Staphylococcus aureus, are mistaken for a bite from this type of spider. If someone develops a skin infection, other possible causes need to be ruled out before jumping to conclusion that the problem is a result of a brown recluse spider bite.
The other poisonous spider in our area is the black widow, which is very common. They prefer dark, protected spots, like woodpiles, crevices and under rocks. The spiders are sometime found indoors in attics, basements and under cabinets. The black widow is roughly 11⁄2 inches long and has a shiny black color with a red hourglass mark on its abdomen. The bite is followed by pain and swelling, nausea and difficulty in breathing, but it is rarely fatal.
Anyone who has been bitten needs to receive medical treatment as soon as possible. The spider is not aggressive and only bites when provoked. Be careful about leaving boots and shoes outside or in garages for long periods of times. These spiders have been known to move into them and make themselves at home. The unknowing person puts on the footware and may be bitten by the spider.
Most spiders are not a threat to people, and the bites from the two poisonous species in our area are quite rare. To control spiders, keep closets, basements, attics and other areas of the home clean. Outside, remove wood piles, old boards and other debris from around the home and in areas where children play. Cut vegetation away from structures and mow the grass frequently.
Homeowners can control spiders indoors by vacuuming the spiders and their webs. Caulk or seal openings on the sides of the house to keep them and other pests out. If the problem persists, consider consulting a pest control service.
Timothy Daly, is an Agricultural and Natural Resource Extension Agent with Gwinnett County. He can be contacted at 678-377-4010 or firstname.lastname@example.org.