Reproductive potential of gamma-irradiated males of the meadow grasshopper Chorthippus parallelus (Zetterstedt) (Orth., Acrididae)

Males of the meadow grasshopper Chorthippus parallelus were treated with five doses ranging from 0 (control) to 140 Gy of gamma irradiation. There was a negative correlation between irradiation dose and post-treatment longevity. Individuals irradiated with the lowest dose lived, on average, longer than the controls. This was presumably not attributable to an energy allocation from tissue since at the time of death there were no dry weight differences. There was a negative correlation between irradiation dose and number of faecal pellets excreted in a period 6–9 days after treatment but not before. There were no negative correlations between irradiation dose and the time required to copulate, copulation duration and ejaculate size. The proportion of tail-less sperm did not differ between the treatments.