Editor choice

Editor’s Choice for the week of October 25, 2021 – PCT

DAVIE, Fla. – A team of students from the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) has determined that less is more when it comes to colony size subterranean termites that must consume a chemical known as a chitin synthesis inhibitor (CSI) before the colony is eliminated.

The study, published in the Journal of Pest Science, takes a closer look at the amount of bait needed to eliminate an underground colony.

As the leading industry standard used in bait systems, CSI baits were first used commercially in the mid-1990s. The bait systems function as slow-acting agents. Current commercial formulations can provide a cost-effective and long-lasting solution to potential damage caused by subterranean termites.

“If termites feed on the bait, it can result in colony elimination within months, as University of Florida researchers have demonstrated over the past three decades through dozens of studies. keys,” said Thomas Chouvenc, assistant professor of urban entomology at the University of Florida. UF/IFAS Fort Lauderdale Research and Education Center (REC).

“One of the remaining questions we had was, how many termites feeding on the bait does it take to achieve colony elimination?” said Johnalyn Gordon, a recent UF/IFAS graduate with a master’s degree.

“From a previous study in our lab, we knew that it only takes one day of bait-feeding termites to reach a colony-wide lethal dose, but how many termites within the colony must be actively feeding on the bait is unclear,” added Joseph Velenovsky, PhD student at UF/IFAS Fort Lauderdale REC.

The two students, under Chouvenc’s supervision, worked with 1.68 million termites at REC Fort Lauderdale to answer this question.

“They used 27 large termite colonies that the team spent four years rearing in the lab, with about 62,500 termites in each one,” Chouvenc explained.

“It was quite a task to show that bait-sharing behaviors occurred at the termite colony level, from only a fraction of foragers,” Chouvenc said.

The efforts of the graduate student duo paid off. They were able to determine that it takes less than 5% of the entire termite population of a colony feeding on a bait station for a short duration to achieve colony elimination.

More importantly, they demonstrated that it only takes 77 milligrams of a termite-specific pesticide to kill one million termites, confirming that CSI termite baits remain the world’s most environmentally friendly termite control technology. available environment.

“It was remarkable to observe that only a small portion of the bait-feeding foragers were enough to kill the colonies,” Velenovsky said.

“Even more remarkably, if a small number of workers feed on a tiny amount of bait for only a few days, the colony has already reached a ‘point of no return’ and is doomed to be eliminated within 90 days. “, explained Gordon.

The study concluded that although subterranean termites can be seen in bait stations for up to three months, the colony is technically already dying within the first week, even after a small number of termites feed on it.

“If the termites feed on the bait, they’re already dead, but they don’t know it yet,” Gordon concluded.