Evidence of predatory cannibalism in Drosophila larvae under laboratory conditions is reported this week in Nature Communications. The work reports that this behaviour, which is exhibited in what is normally a non-carnivorous species, may contribute to survival under conditions of malnutrition.
Roshan Vijendravarma and colleagues show that, under crowded laboratory conditions, cannibalistic behaviour is exhibited by young fruit fly larvae which regularly attack and consume older larvae as the latter prepare for pupation. Odours released from attacked victims attract more consumers to the site of attack, making cannibalism a group behaviour. The authors provide evidence that cannibalistic diets also induce plasticity of larval mouthparts, and that populations maintained under malnutrition conditions for a hundred generations evolved to be more efficient as cannibals.