Sexual cooperation relies on food controlled by females in agromyzid flies

A sex difference in mating optima generates antagonistic traits that impose costs on the opposite sex. This conflict can be mediated by food that increases mutual benefits. Although current understanding of sexual cooperation involving food is based exclusively on mating systems with male food control, recent studies have suggested universal female food control across taxa. However, there have been no empirical studies testing food's role in facilitating sexual cooperation in this scenario. Here, we examined the interplay of food availability and mating in the pea leafminer, Liriomyza huidobrensis, the males of which feed on the exudates from the leaf punctures created by female ovipositors. Given the association between female oviposition and food production, we infer that food controlled by females may alter male optima in mating and thus modulate male courtship strategies for mating. Mating stimulated females to produce abundant punctures, which benefited male feeding and survival. When males were deprived of the punctures, they adopted an elaborate dancing behaviour, leading to increased receptivity of females. However, when males adopted an alternative strategy of directly approaching females, they obtained fewer punctures. After preferential mating with dancing males, females significantly prolonged their life span and increased offspring numbers. Sexual cooperation in leafminers can be explained by the nutritional composition of plant exudates, which we found contain abundant sugars and amino acids. The plant exudates are vital food for males, but their nutritional value and availability rapidly declined with time. Our study reveals that the food produced by females can provide mutual benefits to male survival and female reproduction. Our study of food control by females extends our understanding of evolution in sexual cooperation. (C) 2019 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.