Fruit Flies Medicate Offspring After Seeing Parasites

Abstract

Mother Knows Best Fruit flies feed on decomposing fruit, a food source rich in alcohol, and thus have evolved a high alcohol tolerance not shared by many other species. High levels of ingested alcohol protect fly larvae against parasitic wasp larvae. Kacsoh et al. (p. 947 ) show that this therapeutic use of alcohol to combat a parasite has an intergenerational component. When fly mothers were permitted to see parasitic wasps, they preferentially laid their eggs on substrates containing high alcohol levels as a way to medicate their offspring against potential infection.