Public healthNew insect repellant may be thousands of times stronger than DEET

Published 11 May 2011

The Bill & Melinda Gates Foundation has been supporting a major interdisciplinary research project to develop new ways to control the spread of malaria by disrupting a mosquito’s sense of smell; as part of the project, Vanderbilt University researchers developed an insect repellant which is not only thousands of times more effective than DEET — the active ingredient in most commercial mosquito repellants — but also works against all types of insects, including flies, moths, and ants

Each of the "hairs" is tuned to a different scent substance // Source: fsu.edu

Is it possible to develop an insect repellant that not only will be thousands of times more effective than DEET — the active ingredient in most commercial mosquito repellants — but will also work against all types of insects, including flies, moths, and ants.

This is now possible by the discovery of a new class of insect repellant made in the laboratory of Vanderbilt Professor of Biological Sciences and Pharmacology Laurence Zwiebel and reported this week in the online Early Edition of the Proceedings of the National Academy of Sciences. A Vanderbilt University release reports that in preliminary tests with mosquitoes, the researchers found the new class of repellant, called Vanderbilt University Allosteric Agonist or VUAA1, to be thousands of times more effective than DEET. The compound works by affecting insects’ sense of smell through a newly discovered molecular channel.

“If a compound like VUAA1 can activate every mosquito odorant receptor at once, then it could overwhelm the insect’s sense of smell, creating a repellant effect akin to stepping onto an elevator with someone wearing too much perfume, except this would be far worse for the mosquito,” said Patrick Jones, a post-doctoral fellow who conducted the study with graduate students David Rinker and Gregory Pask.

The researchers have just begun behavioral studies with the compound.

“It’s too soon to determine whether this specific compound can act as the basis of a commercial product,” Zwiebel cautioned. “But it is the first of its kind and, as such, can be used to develop other similar compounds that have characteristics appropriate for commercialization.”

The discovery was made during tests that are part of a major interdisciplinary research project to develop new ways to control the spread of malaria by disrupting a mosquito’s sense of smell, supported by the Grand Challenges in Global Health Initiative funded by the Foundation for the NIH through a grant from the Bill & Melinda Gates Foundation.

“It wasn’t something we set out to find,” Rinker said. “It was an anomaly that we noticed in our tests.”

A different sense of smell

The discovery of this new class of repellant is based on insights that scientists have gained in the last few years about the basic nature of the insect’s sense of smell. Although the mosquito’s olfactory system is housed in its antennae, ten years ago biologists thought that it worked in the same way at the molecular level as it does in mammals.