Within 30 days of that first day of feeding, the bait significantly weakens termite colonies, said Thomas Chouvenc, a UF/IFAS assistant professor of entomology and lead author of a new study. After 90 days, the insecticide kills the termite colonies, Chouvenc said. This process is far shorter than scientists originally thought, he said.
“Within a month after feeding on the bait, termites became sluggish and slowed their feeding activity. Therefore, even if the termites were still alive, they would not be causing much damage,” said Chouvenc. “This study supports the use of baits for control of subterranean termite colonies, especially for aggressive species such as the Formosan subterranean termite and the Asian subterranean termite.”
In the study, scientists used an insecticide called a chitin synthesis inhibitor (CSI), used in the Sentricon termite baiting system, which was invented by UF/IFAS entomology professor Nan-Yao Su. CSI has been an established termite killer for more than 20 years, but until now, scientists didn’t know how long termites had to eat the bait to be killed.
For their study, Chouvenc and Su raised colonies in their laboratory for more than four years. That way, they could expose the CSI bait to whole colonies, while monitoring the termites.
Researchers kept the termite colonies in large containers in the laboratory and let them feed on CSI baits for one day. After a day, scientists removed the bait and monitored termite deaths for 90 days. That’s when they found the dead termite colonies.
The study’s findings come as helpful news to anyone who wants to protect their home or business from the pest, say UF/IFAS entomologists. Termites cause huge economic costs to society — as much as $40 billion dollars per year worldwide, according to UF/IFAS researchers. Half the structures in South Florida will be at risk of infestation by subterranean termites by 2040, UF/IFAS entomologists estimate.
In addition to killing termite colonies in less time, scientists showed they need tiny amounts of the active ingredient in the insecticide to kill them, said Chouvenc, who along with Su, is a faculty member at the UF/IFAS Fort Lauderdale Research and Education Center.
The study by Chouvenc and Su is published in the Journal of Economic Entomology.