Black Widows Are Losing to Brown Widows in the Fight for Your Attic and Garage - The New York Times

Three species of black widows are native to North America, including the Southern black widow, Latrodectus mactans. Exceedingly shy insect hunters, black widows like to live in crawl spaces, woodpiles and sheds. This fondness for human habitation does occasionally lead to people getting bit — 1,004 cases in 2021, according to America’s Poison Centers — but deaths are extremely rare. “Black widows generally don’t bite when harassed,” preferring to run, play dead or flick webbing at a poking finger, Mr. Coticchio said. “It’s only pinching them that’ll get you bit.”

Brown widows — a closely related species — arrived in Florida around 1935, likely from South Africa. A single mother produces multiple egg sacks and potentially thousands of spiderlings. Like black widows, brown widows like to live around people. Brown widows are less venomous than their native cousins, and aren’t at all shy.

Mr. Cottichio spent several years working as a venomous species zookeeper in California, looking for spiders in his spare time. While hunting for western black widows in suburban Los Angeles, he noticed that wherever they and brown widows overlapped, the black widows eventually disappeared. Upon starting his bachelor’s degree at the University of South Florida, he found the same thing. “Every time I returned to a site, there were less and less of them until there were none.”

via www.nytimes.com

We have both here in Jamul. I've seen more black widows but I've seen a few brown as well. I'll have to check to see if the browns are catching up. Nature, man. It's so competitive.