black widow

Black widow

Name: Latrodectus hesperus

Alias: Black widow. This is a common spider to see during summer and fall months, and not just because it likes to get into the Halloween spirit. They are completely black and have a little shine to their skin. Females are about twice the size of males and have a distinct red hourglass shape on their belly. They are considered “web weavers” and spin a stereotypical spiderweb across secluded openings such as a window seal or in a garage. It is called a widow because the female eats the male after mating. While that is possible, most males get away safely with this particular species of black widow because they prefer to mate with well fed females.

Crimes: Female black widows have a powerful neurotoxin in their venom that has a profound effect on most mammals. It causes pain and swelling. In rare cases it has caused death in humans, although most bites are easily treatable by medical professionals.

Redeeming qualities: Despite what horror films and your own arachnophobia tells you, black widows are not considered aggressive at all. They prefer to save their resources for feeding and will try to get away at all costs. Most bites happen when a spider is unknowingly trapped or pinched.

Sentence: The best way to keep them out of your house is to make sure that you have all of your doors and windows properly sealed. Keep clutter down to avoid convenient hideaways for them as well as give yourself plenty of visibility so you don’t accidentally squash them. Glue traps can be good monitoring tools. Over the counter pesticides are also readily available for black widow control both indoors and outdoors. Be sure to read and follow label instructions.

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-270-4031 or email