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

Males of the meadow grasshopper Chorthippus parallelus were treated with fi ve doses ranging from 0 (control) to 140 Gy of gamma irradiation. There was a negative correlation between irradiation dose and post-treatment longevi ty. Individuals irradiated with the lowest dose lived, on average, longer t han the controls. This was presumably not attributable to an energy allocat ion from tissue since at the time of death there were no dry weight differe nces. There was a negative correlation between irradiation dose and number of faecal pellets excreted in a period 6-9 days after treatment but not bef ore. There were no negative correlations between irradiation dose and the t ime required to copulate, copulation duration and ejaculate size. The propo rtion of tail-less sperm did not differ between the treatments.