UCR Studying Use of IGRs to Control Drywood Termites

Drywood termites, which live and feed inside wooden structures, molt roughly seven times during their lives. Researchers at University of California, Riverside have found that disrupting this molting process can effectively collapse termite colonies.

A new study published in the Journal of Economic Entomology examined the insect growth regulator bistrifluron, a chemical that prevents termites from producing chitin, the material that forms their protective exoskeletons. Researchers found the treatment eliminated about 95 percent of western drywood termite colonies while showing no off-target effects on mammals.

“This chemical is more environmentally friendly than ones traditionally used for drywood termite infestations,” said Nicholas Poulos, corresponding author of the paper. “It’s specific to insects and can’t harm humans.”

As termites prepare to molt, they must form a new exoskeleton before shedding the old one. Bistrifluron blocks that process, ultimately killing the insects.

“Once the termites reach a certain stage, they have to molt. They cannot avoid that,” said Dong-Hwan Choe, senior author of the study. “With a lethal dose of this chemical, they’ll try to shed their old exoskeleton but won’t have a new one ready to protect them.”

The researchers observed that treated termites slowed their feeding before dying from incomplete molting. Because termites share food within the colony, the chemical spread to other members, leading to colony collapse in about two months.

The study suggests insect growth regulators could provide a lower-impact, localized alternative to whole-structure fumigation. Researchers also believe the treatment may remain active in wood long enough to help prevent future infestations.

Source: UCR.edu