Predator-released hydrocarbons repel oviposition in the mosquito Culiseta longiareolata.

Predator detection via predator-released kairomones is common for prey foraging for food and ovipositing female. However, the chemical identity of predator-released kairomones remains elusive in general and particularly for predator-released kairomones used by ovipositing females. Here we show that two volatile hydrocarbons, n-heneicosane and n-tricosane, which are released by the predatory backswimmer, Notonecta maculata Fabricius, into freshwater pools, repel oviposition of the mosquito, Culiseta longiareolata Macquart. This response was shown in a series of behavioral tests with environmentally relevant chemical concentrations in outdoor mesocosm experiments. The repellent effects of the two compounds were additive.