Raul Villanueva, an entomologist with Texas AgriLife Extension Service, told The Brownsville Herald ( http://bit.ly/1eiB00e) that other than a major infestation in Weslaco in 2010, there have been no reports of tawny crazy ants in South Texas.
"In this area we have abundant ants," Villanueva said. "That's important, probably. I believe it balances things out."
The tawny crazy ants, called crazy because of their sudden erratic movements, can cripple electrical equipment, kill small livestock and make it nearly impossible for people to enjoy their backyards.
Robert Puckett, an associate research scientist with the Texas A&M Center for Urban & Structural Entomology in College Station, said the Rio Grande Valley is home to "a series of very aggressive, efficient, invasive ant species."
"You've found yourself at sort of the epicenter of a battle royale between invasive ant species," he said. "I don't personally know of another situation where Argentine ant and tawny crazy ant populations are overlapping."
Puckett added that it may be the case that the wide variety of ant species in the Valley has kept the tawny crazy ant from spreading as much as it has in places where its only enemy is the fire ant.
"It becomes a competition story," he told the newspaper. "They're competing for the resource budget that's available to them. If they can command a greater share than other species, then they will persist."
It's probably not so much a case of equilibrium as it is that somebody's winning—it's just taking a while, according to Puckett. "It's happening slowly enough that it's difficult to see it," he said.
Tawny crazy ants were discovered in the Texas city of Pasadena in 2002 by local exterminator Tom Rasberry. These ants, now present in at least 27 counties are also called Rasberry crazy ants, and are known for their fast reproduction rate and being attracted to electricity. When they infest a house, often they have to be shoveled out from walls and crawlspaces.
Information from: The Brownsville Herald, http://www.brownsvilleherald.com