Time of Emergence, Mating, Sperm Movement, and Transfer of Ejaculatory Duct Secretory Fluid by Heliothis virescens (F.) (Lepidoptera: Noctuidae) under Reversed Light-Dark Cycle Laboratory Conditions

Abstract

In laboratory studies under reversed light-dark photoperiods, highest percentages of Heliothis virescens (F.) moths emerged during the first 6 h after initiation of the dark period. The primary simplex area of newly emerged male moths contained a dense, gel-like, creamy-white secretory fluid that became orange white in 5 to 10 h and progressively deepened in color to a dark-red-maroon color by 24 to 48 h. Apyrene sperm occurred in the duplex of the ejaculatory duct of male moths within 1 to 3 h after emergence from the pupae and sperm bundles within 5 to 7 h. The red fluid remained identifiable in unmated male moths through their lives and was transferred to female moths during the first mating and did not recur in the male simplex. The material remained identifiable in the female's bursa copulatrix during her entire life. First moth matings occurred ca. 3 h after the initiation of the dark period, and about 98% of the mating occurred between h 3 and 8 of the dark period. No sperm was found in the duplex immediately after mating occurred. However, apyrene and eupyrene sperm descended from seminal vesicles or testes to the duplex within 6 to 9 h after mating. Numbers of eggs laid and eggs hatched from females mated to virgin males transferring the red secretory fluid (first mating) were not significantly different than numbers of eggs laid and eggs hatched from females mated to previously mated males. The simplex of 32% of native H. virescens male moths collected for a 7-day period from 31 August to 7 September 1983 contained red secretory material, indicating they were unmated males. The secretory area of the simplex of the remaining male moths collected contained transparent pale yellow to greenish material, indicating they were previously mated moths.