Notes From The Wildlife Rescue Center: The Missouri Black Widow and Brown Recluse Spiders

By Kristin Clayton, volunteer


Just the name, Black Widow Spider (Latrodectus mactans) sends chills up your spine. The Black Widow is characterized by its jet black body with the signature red hourglass shape on the underside of its abdomen. The abdomens are normally much larger than the rest of the body and females are larger than males. Only the female Black Widow spiders are venomous.

Black Widows often construct their webs among trash, litter, boards, and rocks. Females are shy and nocturnal and rarely leave the web, which is unfortunately, where most attacks occur. Often, a person brushes against a web or accidentally pins a Black Widow and she bites in defense.

When bitten, the toxin heads for the nervous system. Severe pain usually begins at the site of the bite, followed by dizziness, nausea, blurred vision and labored breathing. If a physician is contacted, fatalities are very rare and recovery is usually quick.

The Brown Recluse Spider (Loxosceles recluse) was found in about 70 percent of the homes sampled in a small study within Missouri, and is usually found in dry, cluttered places.  Colors of the Recluse vary from light tan to dark brown and their six eyes are usually quite noticeable (although I don’t suggest getting a close look to make sure). The most distinctive marking for a Brown Recluse is a fiddle shaped marking which is darker than the rest of the body and starts just behind the eyes, extending to the back of the head, with the neck of the fiddle pointing to the rear.

Most encounters with this venomous creature happen at night when the Brown Recluse is active and foraging for food. Unlike the Black Widow, both the males and females are venomous. When you are bitten by a Brown Recluse, painful reactions occur almost immediately. A small white blister will form at the bite location and the area will swell and become hard to the touch. Medical attention should be sought quickly to prevent severe reactions and long-term effects. Recovery is actually very slow and can even take a few weeks, but again fatalities are rare.