Chemists have revealed the chemistry of kairomones emitted by mosquito predators. These early-warning compounds cause mosquitoes to lay fewer eggs.

The “backswimmer” Notonecta maculata emits kairomones, revealed to be hydrocarbons, n-heneicosane and n-tricosane, that act as an alarm system to female mosquitoes causing them to lay fewer eggs in pools where the predator lives. The adaptation may increase the reproductive capacity of the mosquitoes, but might also be exploited to control mosquitoes where people live and so reduce the spread of diseases carried by mosquitoes, including malaria. These repellant compounds apparently work synergistically, according to research published by Joel Cohen and colleagues at the University of Haifa, Israel.

• Predator-released hydrocarbons repel oviposition by a mosquito
  A. Silberbush, S. Markman, E. Lewinsohn, E. Bar, J. E. Cohen, L. Blaustein,
  Ecol. Lett. 2010, 13.
  DOI: 10.1111/j.1461-0248.2010.01501.x