Q. Our garage and yard are infested with brown widow spiders. They are brown with spots and a have bright orange hourglass on the belly. Are these common in this area? I never heard of them before until I looked them up in the Internet to see what they were.
A. The brown widow is suspected to have evolved in Africa, although it was first described from South America, which adds confusion as to where it might have originated, according to the University of California Riverside Center for Invasive Species Research, online at cisr.ucr.edu/brown_widow_spider.html
“The Brown Widow Spider is a cosmopolitan tropical and subtropical spider having established populations in Hawaii, Florida, some Caribbean Islands, parts of Australia, South Africa, Japan, and Cyprus,” according to the website.
In North America, the Brown Widow Spider was restricted for many decades to the Florida peninsula.
“However, around the year 2000, it started showing up in other Gulf Coast states. Brown widows are now known from Texas to Georgia and South Carolina. As specimens were found in new locations in the southeastern United States, this species was simultaneously being collected with greater frequency in southern California. The first specimens were collected in Torrance in 2003. After that, the spider was found with greater frequency in Los Angeles, Orange and San Diego counties,” the website says.
The brown widow has apparently made inroads into North Carolina, said Susan Brown, horticulture agent with Cooperative Extension of New Hanover County.
“The brown widow spider is fairly timid. I currently have a live sample in my office in a jar,” Brown said. “They are brown instead of black and they do have an orange hourglass on the belly.”
Brown widow spiders are rarely known to bite “and are unable to inject a substantial amount of venom into a victim,” Brown said.
The spiderlings do not bite. They also have a very distinct egg sac.
“They hatch out so many babies it is scary! They have been found as close as South Carolina and are now showing up in North Carolina,” Brown said.
In terms of coping with the eight-legged intruders, “I would think that any chemical that would kill a spider would kill it. They are not hard to kill,” Brown said
“I am sending my live sample to N.C. State because I am not certain that a known case has been documented in New Hanover County, but they are certainly here. I would not recommend the homeowner handling the spiders even though they are not nearly as dangerous as the black widow,” Brown said.
Brown attached several websites containing information about brown window spiders: http://cisr.ucr.edu/brown_widow_spider.html
http://tolweb.org/Latrodectus_geometricus/93770 ( picture of egg sac)
Date posted: December 7, 2012
User-contributed question by:
Linda S. Hudgins