Grand Teton National Park Report
Male sagebrush crickets (Cyphoderris strepitans) permit females to engage in an unusual form of sexual cannibalism during copulation: females feed on males' fleshy hind wings and ingest haemolymph oozing from the wounds they inflict. These wounds are not fatal, and normally only a portion of the hind wings are eaten at any one mating, so that mated males are not precluded from mating again. However, non-virgin males have fewer resources to offer females than do virgin males, such that females should be selected to preferentially mate with virgin males. Because previous work has indicated a lack of pre-copulatory female choice, we tested the hypothesis that females accept matings with non-virgin males, but discriminate against them afterwards by re-mating sooner than they otherwise would after matings with virgin males. If the last male to copulate with a female prior to egg laying does in fact sire the majority of her offspring, then such post-copulatory behavior would constitute a form of female choice. To test this, we experimentally manipulated both female diet (high protein vs. low protein), and the female's ability to feed on males' wings during mating. We predicted that females prevented from wing feeding and held on a low protein diet would remate sooner than females allowed to wing feed and held on a high protein diet. We measured the amount of time males spent calling in mating trials, and the time to first and second mountings and matings for each female. Our results reveal an effect of wing treatment on the time to first mating. Low protein females mated with winged males significantly more readily than they did with dewinged males. Female diet also had a significant effect on the time to first mounting. Females fed only lettuce (low protein) mounted males sooner than females provisioned with apple and a bee pollen supplement (high protein), indicating that a female's overall nutrient intake may determine her propensity to mate regardless of the mating status of the male she is paired with. No effect of diet or wing treatment was found for time to second mounting or mating.
Johnson, J. Chadwick; Ivy, Tracie M.; Eggert, Anne-Katrin; and Sakaluk, Scott K.
"Post-Copulatory Female Choice in Sagebrush Crickets,"
University of Wyoming National Park Service Research Center Annual Report: Vol. 20
, Article 11.
Available at: http://repository.uwyo.edu/uwnpsrc_reports/vol20/iss1/11