Beet Armyworm (Lepidoptera: Noctuidae): Effects of Age at First Mating on Reproductive Potential

Abstract

The effects of age at the first mating on the reproductive potential of the beet armyworm, Spodoptera exigua (Hubner), was studied in the laboratory. Both the fecundity and fertility of eggs laid were significantly affected (P < 0.01) by age of males and females at the time of mating. Delayed mating by females increased longevity but decreased fecundity and fertility (P < 0.05). Delayed mating by males increased longevity (P < 0.05) but decreased the number of spermatophores they transferred to females (P < 0.01). The number of spermatorphores transferred during mating affected female fecundity and fertility (P < 0.01). The optimum age for the first mating for both males and females was 1-2 days post-emergence. Delaying the first mating by either sex beyond 3-4 days post-emergence significantly, and adversely, impacted the reproductive potential of the beet armyworm.