The association of the development of the internal reproductive organs of male desert locusts, Schistocerca gregaria (Orthoptera: Acrididae), with age, phase and the effect of exposure to pheromones

. The regulation of the development of the male reproductive organs in insects is still an open question. Although the desert locust, Schistocerca gregaria , has been extensively examined, there is little information on the effects of phase and pheromones on the development of the male reproductive organs. This study clari fi ed the association of these two factors with reproductive development (length or width of each organ) of the testis, testicular follicles, accessory glands, and seminal vesicles in this locust. The width of the follicles and width and length of the accessory gland mass are signi fi cantly associated with phase (solitary or gregarious). Developmen of all reproductive organs is age dependent as these organs developed in the adult stage. The development of follicles and accessory glands (width) in males in the fi rst two weeks of adulthood was promoted by exposing them to pheromones from mature adults, but not from nymphs. These results indicate the incidence of male reproductive development is associated with phase and affected by pheromones.