Chlorfluazuron is an insect growth regulator for controlling the major insect pests in crops. This paper describes the effects of sublethal doses （LD10：1.00 ng/larva; LD3o： 3.75 ng/larva） of chlorfluazuron on sper...Chlorfluazuron is an insect growth regulator for controlling the major insect pests in crops. This paper describes the effects of sublethal doses （LD10：1.00 ng/larva; LD3o： 3.75 ng/larva） of chlorfluazuron on spermatogenesis in the adults of the common cutworm, Spodoptera litura （F.）. Chlorfluazuron was applied topically to the newly-ecdysed fifth-instars ofS. litura under laboratory conditions. The secondary spermatocytes, spermatids, elongated spermatocytes with mature sperm and eupyrene sperm bundles were present in testis of newly emerged, 1 and 2 day-old adults, but gradually decreased in their numbers in the controls. However, the spermatogonia were not present in newly emerged, 1 and 2 day-old adults. Moreover, primary spermatocytes were present （174 ± 4.0） in newly emerged adults, but not found in 1 and 2 day-old adults. In the testes of newly emerged LD10-treated adults, the numbers of eupyrene and apyrene sperm bundles were significantly reduced compared with controls, and even significantly reduced in LD30-treated adults compared with LDlo, however, their ratios were not affected. Moreover, the pattern of spermatogenesis was the same in LD10- and LD30-treated male adults compared with controls. Furthermore, numbers of developing spermatocytes were significantly reduced in the LD10 compared with controls, and even significantly reduced in LD30-treated male adults compared with LD10. In newly emerged adults, the width and length of elongated spermatocytes with mature sperm were significantly reduced in LDlo- and more significantly reduced in LD30-treated compared with controls of S. litura. In vas deferens of untreated pre- and newly emerged adult male, both eupyrene and apyrene sperm bundles were found, however, in treated pre-adult male, only apyrene sperm bundles and in treated newly emerged adult male, fe, w eupyrene and numerous apyrene sperm bundles were found. It is concluded that spermatogenesis was significantly affected by chlorfluazuron.展开更多
文摘Chlorfluazuron is an insect growth regulator for controlling the major insect pests in crops. This paper describes the effects of sublethal doses （LD10：1.00 ng/larva; LD3o： 3.75 ng/larva） of chlorfluazuron on spermatogenesis in the adults of the common cutworm, Spodoptera litura （F.）. Chlorfluazuron was applied topically to the newly-ecdysed fifth-instars ofS. litura under laboratory conditions. The secondary spermatocytes, spermatids, elongated spermatocytes with mature sperm and eupyrene sperm bundles were present in testis of newly emerged, 1 and 2 day-old adults, but gradually decreased in their numbers in the controls. However, the spermatogonia were not present in newly emerged, 1 and 2 day-old adults. Moreover, primary spermatocytes were present （174 ± 4.0） in newly emerged adults, but not found in 1 and 2 day-old adults. In the testes of newly emerged LD10-treated adults, the numbers of eupyrene and apyrene sperm bundles were significantly reduced compared with controls, and even significantly reduced in LD30-treated adults compared with LDlo, however, their ratios were not affected. Moreover, the pattern of spermatogenesis was the same in LD10- and LD30-treated male adults compared with controls. Furthermore, numbers of developing spermatocytes were significantly reduced in the LD10 compared with controls, and even significantly reduced in LD30-treated male adults compared with LD10. In newly emerged adults, the width and length of elongated spermatocytes with mature sperm were significantly reduced in LDlo- and more significantly reduced in LD30-treated compared with controls of S. litura. In vas deferens of untreated pre- and newly emerged adult male, both eupyrene and apyrene sperm bundles were found, however, in treated pre-adult male, only apyrene sperm bundles and in treated newly emerged adult male, fe, w eupyrene and numerous apyrene sperm bundles were found. It is concluded that spermatogenesis was significantly affected by chlorfluazuron.
