"The arachnids, which likely migrated to the United States from South Africa, seem to be attacking black widow spiders in some parts of the country."
"Few spiders in the United States have a more fearsome reputation than black widows. But throughout the South, the bulbous arachnids with red hourglasses on their bellies are engaged in a lethal competition with the brown widow, a relative from abroad — and they’re losing.
This isn’t a case of one species outcompeting another for food or habitat. In research published Monday in the Annals of the Entomological Society of America, biologists found that young brown widow spiders have a dramatic tendency to seek out and kill their American cousins.
“Brown widows will aggressively go after black widows, chase them down,” said Louis Coticchio, a science tutor at St. Petersburg College in Florida and an author of the paper. “They don’t play well with being neighbors.”"