Location: Southern Insect Management ResearchTitle: 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.
|HIROYOSHI, SATOSHI - International Centre Of Insect Physiology And Ecology|
|MITSUNAGA, TAKAYUKI - National Agriculture And Food Research Organization (NARO), Agricultrual Research Center|
|Reddy, Gadi V.P.|
Submitted to: European Journal of Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2022
Publication Date: 8/11/2022
Citation: Hiroyoshi, S., Mitsunaga, T., Reddy, G.V. 2022. 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.. European Journal of Entomology. 119:300-308. https://doi.org/10.14411/eje.2022.031.
Interpretive Summary: We investigated male sperm storage in the desert locust Schistocerca gregaria. Phase (solitary or gregarious) did not affect sperm distribution in the vas deferens and seminal vesicle. Sperm accumulation of the seminal vesicle in gregarious locusts was promoted than in solitary ones. Pheromones received from neither mature adults nor nymphs affected sperm distribution in the vas deferens and seminal vesicle. However, sperm accumulation of seminal vesicle was promoted in the gregarious locusts received pheromones from mature adults than those obtained from the nymphs, especially seven days after adult emergence.
Technical Abstract: In general, sperm produced in the testis are moved into the seminal vesicle via the vas deferens in insects, where they are stored. How this sperm movement is controlled is less well understood in locusts or grasshoppers. In this study, the effects of age, phase variation and pheromones on male sperm storage were investigated in the desert locust, Schistocerca gregaria (Forskål). In this locust, a pair of ducts, the vasa deferentia connect the testes to a pair of the long, slender seminal vesicles that are folded approximately thirty times and where the sperm are stored. We found that phase variation affected the level of sperm storage in the seminal vesicle. Moreover adult males that detected pheromone emitted by mature adult males showed enhanced sperm storage compared with males that received the pheromone emitted from nymphs: The former, adult male pheromones are known to promote sexual maturation of immature adults of both sexes, whereas the latter, nymphal pheromones delay sexual maturation. Most mature adult males had much sperm in the vasa deferentia at all times examined, suggesting daily sperm movement from the testes to the seminal vesicles via the vasa deferentia. As adult males aged, sperm were accumulated from the proximal part to the distal end of the seminal vesicle. Many sperm remained in the seminal vesicle after mating. These results suggest that young or new sperm located near the proximal part of the seminal vesicle could be used for mating.