Male accessory gland substance: an egg-laying stimulant in Melanoplus sanguinipes (F.) (Orthoptera:Acrididae)

Abstract

The rate of egg deposition by mature virgin females of the migratory grasshopper, Melanoplus sanguinipes (F.), increased markedly after implantation of accessory glands from mature males. Implants consisting of one-half of a complete set of glands, or of the 10 short hyaline glands alone, were about equally effective in increasing the rate of egg deposition. However, in each case the oviposition rate was less than that of normally mated females of the same age. Implanting only the white glands of the accessory gland complex had a lesser effect on egg-laying and implants of the long hyaline gland or of the seminal vesicle had little or no effect.Our results indicate that the physical act of mating per se or the presence of sperm probably do not provide the primary stimulus to egg-laying. The abdominal location of the implanted accessory gland does, however, suggest that some diffusible chemical substance is responsible for increasing egg deposition in these virgin females.