Age-dependent changes in calling effort in the bell cricket Meloimorpha japonica

We investigated how male age and body weight influence male mating effort in the bell cricket Meloimorpha japonica. We adopted a longitudinal approach to study resource allocation to male mating effort (calling duration during 24 h) in the bell cricket. Calling durations and body weight of each male were measured at 7-8 days (young age), 14-15 days (middle age), and 22-25 days (old age) after the final molt. Calling duration increased between young and middle age. During the period between middle and old age, the amount of change in the calling duration was positively correlated with the body weight. The results suggested that older (i. e., low residual reproductive value) and better quality males invested more resources in mating effort.