Sex Pheromones of Noctuid Moths. XIII. Changes in Pheromone Quantity, as Related to Reproductive Age and Mating History, in Females of Seven Species of Noctuidae (Lepidoptera)2

Abstract
Changes in sex pheromone quantity in relation to age, reproductive maturity, and mating were determined in females of 7 species representing 3 subfamilies of Noctuidae. Species studied were: subfamily Plusiinae—Trichoplusia ni (Hübner), Psendoplusia includens Walker, and Rachiplusia on (Guenée) ; subfamily Amphipyrinae— Prodenia ornithogalli Guenée and Spodoptera exigua (Hübner) ; and subfamily Heliothinae— Heliothis zea (Boddie) and H. virescens (F.). In general, for each species, rapid production of sex pheromone occurred within 1.0 day preceding or following emergence from the pupa; the proportion of females mating reached 50% of its maximum level by 0–1.5 days following emergence; and the proportion of females containing at least 20 chorionated eggs reached 50% of its maximum level by 0.5–2.0 days following emergence. The occurrence of a single mating on the third night following emergence did not cause a rapid disappearance of sex pheromone among 5 species studied. This phenomenon is consistent with the fact that females of many noctuid species commonly mate more than once.