The humid, subtropical climate of New Orleans makes it an ideal habitat for some of the creepiest insects and arachnids (eight-legged invertebrates, including spiders). While families may pay to see them--and thousands of non-native bugs--in the Audubon Nature Institute's popular new Insectarium, they can also find many spiders, including a few that are poisonous, within their own homes and backyards.

Widow Spiders in New Orleans

The female brown widow spider, Latrodectus geometricus, is relatively new to the New Orleans area. Ranging from very light to very dark brown with yellow or orange hourglass markings on its underside, it has a more powerful neurotoxin venom than the black widow, also found in New Orleans; however, the brown widow injects a much smaller dose, making it less harmful to humans.

The female black widow spider, Latrodectus mactans, is shiny black and marked with a red hourglass on its underside. Although its venom is a powerful neurotoxin, the spider injects such a small dose that the mortality rate from a bite is extremely low, less than 1 percent.

The male brown and black widow spiders are about half the size of the females and are harmless.

The Brown Recluse Spider

Officially named Loxosceles reclusa, this spider is marked by a dark, violin shape on its top side. While most bites will heal on their own with no medical intervention, some serious complications can develop.

Health Concerns with Poisonous Spiders

At the minimum, bites from the three types of poisonous spiders found in New Orleans will cause pain, burning and swelling at the inject site. Other symptoms can include fever, headache, nausea, lethargy, profuse sweating, shortness of breath, muscle cramps and--very rarely--skin necrosis (the premature death of cells) and blood poisoning. Anyone suspecting a bite from any poisonous spider should seek medical attention quickly to prevent serious health complications.

Non-Poisonous Spiders in New Orleans

House spiders, from the Theridiidae family, are small and mostly brown, with some black and white markings on their abdomen. Jumping spiders, Salticidae, comprise the largest grouping of spiders and vary in shape, size and color. They are distinguishable by their three or four rows of eyes and their ability to jump backward via a spun web. Wolf spiders, representing several species of the Lycosidae family, vary in length—from one-half to two inches long—and can be brown or gray. All are hairy. Yellow sac spiders, Cheiracanthium inclusum and Cheiracanthium mildei, are small, grayish yellow, and often take refuge in clothing.

Avoiding Spider Bites

Controlling spider population is the best way to avoid bites indoors. Vacuum webs, spiders and their eggs, and discard the vacuum bag in a sealed bag. Spiders are killed only when pesticides are sprayed directly on them; however, because spiders eat insects, they can control the amount of insects in a home.

When outdoors, where spider control is not possible, wear shoes as well as thick gloves when working with wood or refuse piles, as they are common habitats for spiders in the greater New Orleans area.