Venomous Brown Widow Spiders Making Themselves Known In Louisiana

Generally found in tropical areas, the brown widow spider is closely related to the black widow spider and is poisonous, according to LSU AgCenter entomologist Dr. Dennis Ring.

Experts say the spider ranges in color from gray or tan to dark brown and may reach 1 inch to 1½ inches long. Like its better-known black widow cousin, the brown widow spider has a yellow-to-orange hourglass marking on the underside of its abdomen. It also has black and white marks on the top of the abdomen and often has dark bands on its legs. "Its venom is more toxic than the black widow’s," Ring said. "But it doesn’t put out as much venom in its bite."

Ring said the brown widow spider is most often found in areas that haven’t been disturbed, such as brush piles, wood piles and areas where hurricane debris has accumulated. They also can show up in crawl spaces, under chairs, in garbage can handles and under flower pots, eaves and porch railings.

"These spiders are shy and are less likely than black widows to bite humans," Ring said. "Nevertheless, they can bite when they come in contact with a person’s skin."

Ring suggests wearing gloves, long-sleeved shirts and long pants when working outdoors, especially in areas that don’t get a lot of human activity.

In addition to recognizing the spiders themselves, Ring points out that the egg sac of the brown widow is different from that of the black widow. The white-to-tan-colored egg sac of the brown widow is lumpy. The black widow’s egg sac is smooth. The egg sac can be found attached to the web and is about one-half inch in diameter.

The best remedy for controlling brown widow spiders is to remove areas where they may nest, according to Ring. The LSU AgCenter entomologist recommends picking up clutter and sealing cracks and crevices around doors and windows, as well as in driveways and sidewalks.

Ring added that brown widow spiders also can be controlled by using spray or powdered insecticides labeled for spiders.