Study summary
Associative learning switches DEET valence from aversive to appetitive in Aedes aegypti
Lazzari CR, De Luca D, Nally A, Dufour C, Vinauger C
Read the original paper- Study type
- Lab
- Year
- 2026
- Species tested
- Aedes aegypti
- Published in
- Journal of Experimental Biology 229(10):jeb251935
- Evidence strength
- Limited evidence
How it was tested
Individual mosquitoes were conditioned in the lab, pairing DEET odor with a reward (a blood meal or plant sugar), then tested on whether they approached DEET afterward.
Summary
A behavior study showing that Aedes aegypti mosquitoes can learn to stop avoiding DEET, and even treat it as attractive, after its smell is repeatedly paired with a reward. It is a mechanism study, not a field test, but it hints at how DEET might fail if used carelessly.
Key findings
After just four training pairings, more than 60% of mosquitoes tried to feed when they smelled DEET alone, and trained mosquitoes chose DEET-treated hands over untreated ones, the opposite of their untrained aversion. The practical caution the authors draw is to keep DEET concentration high by reapplying, since weak, decaying DEET, for example on old treated clothing, is exactly the low-level exposure that could teach mosquitoes to tolerate it.
Limitations
A laboratory conditioning study on individual restrained mosquitoes of one species; it shows a learning capacity, not a documented field-scale loss of DEET's effectiveness.