AUBURN, Ala. – Black Widow spiders are some of the most recognizable spiders. The shiny black body and red hourglass marking on the female spider are clear markers of this spider. This fall, whether working in the yard or cleaning out garages, watch out for these spiders. Xing Ping Hu, an Alabama Extension entomologist, provides the following information about Black Widow spiders and how to manage them.
Black Widow spiders are not aggressive by nature. They only bite when they feel threatened, and even then, not all Black Widows can cause harm. Only adult and larger immature female spiders can penetrate a person’s skin and inject enough venom to cause a painful reaction. Anyone bitten by a Black Widow spider should seek medical attention quickly.
Black Widows can often be found lurking in dark, dry, sheltered and relatively undisturbed places. Some of the places you might find these spiders this fall include:
- stones and rocks
- basements and crawl spaces
- garages and sheds
- jars and tin cans
- decks and outdoor furniture
- building supplies and equipment
- brick veneer and cement blocks
- hollow tree stumps and wood piles
- barrels and plant pots
- old tires
- trash piles
- boxes (water, electrical, children’s toys, etc.)
Hu said to be cautious when working in these areas.
“Please always wear gloves and a long-sleeved shirt when working in the areas where Black Widow spiders may be hiding,” Hu said.
According to Hu, one of the best ways to discourage spiders from taking up residence is to minimize sites around the home where spiders may hide. The next most important step is to sweep, mop or vacuum spider webs in concerning spots. Vacuuming spiders can be an effective control technique, because their soft bodies usually do not survive the process.
While there are various insecticides registered for spider control, they typically do not yield satisfactory results. This is largely because the silk of spider egg sacs repels these mostly water-based products.
These chemicals can kill spiders when direct contact is made. However, control by spraying is only temporary, because the spray residual does not have a long-lasting effect. If a spider-infested area is covered from the elements, homeowners can consider absorptive dust for control. Hu said dust is mostly used in cracks, crevices and enclosed or unused spaces.
More information about black widow spiders can be found in the Alabama Extension publication The Black Widow, ANR-1039. For further information, visit www.aces.edu or contact your county Extension office.