FALL ARMYWORM (LEPIDOPTERA, NOCTUIDAE) MATING EFFECTS OF AGE AND SCOTOPHASE ON PRE-MATING TIME, MATING INCIDENCE, AND FERTILITY

Laboratory studies were conducted to determine premating time requirem ents under different light regimes, influences of duration of scotopha se on incidence of mating, and changes in fertility with age in labora tory-reared fall armyworm, Spodoptera frugiperda (J. E. Smith). Female s required less time after emergence (XBAR = 11.5 h) than males (XBAR = 21.5 h) before active copulation when held under a 15:9 (L:D) h phot operiod. The incidence of mating increased from 0.36 to 0.92 times per 24 h period as the duration of scotophase increased from 0 to 22 h. F ertility was not constant during the life span of either male or femal e moths. Fertility was high throughout most of the adult life, but low (especially for the males) during the first 24 h after emergence and toward the end of its life.