Sexually Dimorphic Developmental Rates in the Caribbean Fruit Fly (Diptera: Tephritidae)

Abstract

Female Caribbean fruit flies, Anastrepha suspensa (Loew), eclosed before males in field-collected and laboratory-reared samples. This dimorphism is due to more rapid female development during pupal, larval, and perhaps even egg stages. Adult females in the laboratory stock and in the field-collected samples eclosed before male members of the same cohort. At the conclusion of pupal development, 92% of females and only 52% of males emerged from the pupal state on the first of two days of eclosion. During the early portion of the larval maturation period, sex ratios were biased toward females and biased toward males at the end ( r 2 = 0.73). Within 72 h of oviposition, 70% of female flies and only 55% of male flies had hatched. Earlier adult female eclosion does not necessarily result in earlier sexual maturation. Males copulated a day earlier than females ($\bar x$ = 6.6 versus $\bar x$ = 7.5 d of age). Earlier female larval development provides an opportunity to separate late-instar male and female maggots. At this point, larvae are still susceptible to attack by parasitic Hymenoptera (e.g., Diachasmimorpha longicaudata (Ashmead)). Mass-rearing facilities might thus be able to use female maggots to rear parasites for inundative releases while holding males for sterile release.