Study: Mosquitoes may learn to associate repellent Deet with feeding
The Story
A study published in the Journal of Experimental Biology suggests that mosquitoes can learn to associate the repellent Deet with the possibility of a blood meal, potentially making the chemical attractive to them under certain conditions. The research, led by Prof Claudio Lazzari of the University of Tours, indicates that a mosquito’s reaction to Deet can be modified by experience, challenging the long-held belief that repellents work solely through chemical properties.
Key Facts
- Deet (N,N-diethyl-meta-toluamide) is widely used in insect repellents, with the UK Health Security Agency recommending products with 50% Deet as the first choice against mosquito bites.
- The study found that 60% of mosquitoes that fed on warm blood while simultaneously exposed to Deet later attempted to bite when exposed to Deet alone.
- In contrast, only 17% of mosquitoes with no prior training, 13% previously presented with Deet alone, 17% that fed on warm blood without Deet, and 23% that fed on warm blood with non-simultaneous Deet exposure showed biting attempts under Deet alone.
- In a separate test, nearly 60% of mosquitoes that previously fed on blood with Deet exposure attempted to bite a researcher’s Deet-treated hand, while untrained mosquitoes universally avoided it.
- Experts, including Dr Nina Stanczyk of ETH Zürich and Prof Francesca Romana Dani of the University of Florence, emphasized that Deet does not lose its effectiveness through normal use and that travelers should continue reapplying repellent as directed.
Conflicting Reports
No conflicting reports identified in the source article.
Still Unclear
The study does not specify how long a mosquito’s learned association with Deet might last under normal conditions, as noted by Prof Dani.
Misconceptions
No widespread misconceptions addressed in the source article.
Key Figures
- Prof Claudio Lazzari, University of Tours, France (lead researcher)
- Dr Nina Stanczyk, ETH Zürich university (independent researcher)
- Prof Francesca Romana Dani, University of Florence (entomologist not involved in the study)
Sources: The Guardian
