UT Invasive project receives grant to fight ants

Tucker Whatley

A $2.7 million grant by the Lee and Ramona Bass Foundation has helped establish the Texas Invasive Species Program, which will research foreign species introduced into the state and methods to reduce their threat to native ecosystems.

Before receiving the grant, the group of researchers behind the program was already working as a part of the Texas Fire Ant Lab to reduce the ecological impact of the foreign ants that were unintentionally introduced into the United States from Argentina during the 1930s.

South American fire ants have had a great detrimental effect on Texas ecosystems, said the program research associate Edward LeBrun. He said the fire ants have displaced native ant species, including seed-harvesting ants that are the main food source of the Texas horned lizard.

“That’s why horned lizards are almost extinct in Texas,” LeBrun said. “They’re very, very rare now, and that [lizard] was a very iconic species in Texas for a long time.”

The grant from the Bass Foundation will fund half of the projected costs of expanding the Fire Ant Lab’s focus to other non-native species that threaten Texas. The Bass Foundation expects the program to match their grant with financial support from other private groups.

About 80 percent of the group’s budget will be used to pay salaries and benefits for researchers and technicians, said Larry Gilbert, professor of integrative biology and director of the Program. The rest of the sum is going toward other expenses, including travel and equipment.

The Bass Foundation awarded the grant for the founding of the program because of its experiences of working with its director in the past, said Pete Geren, executive director of the Bass Foundation.

“There is a long relationship between the foundation and Mr. Gilbert,” Geren said. “The foundation sees his work as important for the state of Texas in addressing an issue that often goes overlooked by many organizations that invest in environmental research.”

Gilbert said the program is attempting curb populations of invasive species by introducing a species into Texas that is a predator of a specific invasive species in its original environment. This method does not completely eliminate the presence of the targeted species, but does help to lower its population to a point where it is no longer considered a pest.

“That is the approach we’ve taken because we’re ecologists,” Gilbert said. “We’re working on ecological methods of controlling species as opposed to dumping poisons on them.”

The Texas Fire Ant Lab has already been using this strategy, LeBrun said. In order to curb the population of fire ants, they’ve introduced phorid flies, predators of fire ants in their native environment in Argentina. 

These flies target the foreign ants specifically, leaving native ant populations alone.

Gilbert said Invasive species like the fire ant are almost always introduced into a new environment by humans. Gilbert said sometimes species are introduced originally for commercial purposes before spreading out of control, like many species of exotic fish that are sold for aquariums. Often they are introduced unknowingly, riding in the cargo hold of ships or in potted plants. Once they establish themselves in foreign environments with few natural predators, they rapidly multiply, crowding out native species and reducing the diversity and overall health of ecosystems.

Among the invasive species the program is focusing its attention on is buffelgrass, a grass native to Africa that was originally introduced to South Texas for cattle to graze on but has now spread and become a fire hazard. One of the species the group is most concerned with is the tawny crazy ant, a newcomer to Texas that poses perhaps an even greater threat than fire ants.

“It’s very different from fire ants in many ways,” Gilbert said. “It is being spread around pretty rapidly now, and it’s really going to be pretty devastating to the wildlife where it lives. It even knocks out fire ants.”

The program is also studying species that have not yet arrived in Texas but could cause significant damage when they do. One such emerging threat is cactoblastis cactorum, a moth that acts as a parasite to opuntia cacti, which include prickly pear. The moth has been spreading through the Southeastern United States, where it has no natural predators.

“When they get to Texas, [the moths] will expand dramatically and cause pretty dramatic system changes,” LeBrun said. “Especially in South and West Texas, where opuntia cacti are such an important part of the ecosystem.”

Though intact ecosystems have many tangible economic benefits, such as naturally purifying water supplies, LeBrun said, this should not be the sole reason to be concerned about the damage to ecosystems caused by invasive species.

“People grew up with these systems, and they have intrinsic value,” LeBrun said. “They’ve been around for millions of years, and the wide-scale disruption of them and the loss of species diversity is something people should just be concerned about, because we care about things that are bigger than us.”

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