Female mate choice is affected by male condition but not female condition in an assassin bug

Abstract Sexual selection theory predicts that females prefer males in good condition because mating with them provides more resources such as sperm, ejaculates and nuptial gifts. The female's condition also affects her mating decisions, and condition‐dependent mate choice may allow her to gain more resources from a mate in the context of fluctuating resource availability. We here investigated how female mating decisions and their fitness consequences varied in the assassin bug Amphibolus venator when the conditions of potential mates and/or the females differed (good or poor condition). Females in both good and poor conditions preferred males in good condition, and females that mated with males in good condition produced more eggs with higher hatch rates. This increase in fitness may be attributed to the males in good condition transferring more ejaculate to the females. In contrast, female mate preference, fecundity and hatch rates were not affected by their own condition. This suggests that females do not choose mates according to their own condition in A. venator . However, the females in good condition laid larger eggs than females in poor condition, implying that females in good condition may invest more per egg to improve their reproductive success. To understand the evolution of female mate choice, it is necessary to investigate the effects of the condition of both sexes on female mating decision and their fitness. In A. venator , male condition may affect mate choice more than female condition.