Effects of ageing and nutrition on the reproductive system of Samea multiplicalis Guenée (Lepidoptera: Pyralidae)

Abstract

AbstractThe influence of ageing, larval dietary nitrogen and adult carbohydrate diets on development of the male and female reproductive systems of Samea multiplicalis Guenée are described. Mature oocytes appeared in the ovarioles of one-day-old females and remained constant in number from one to three days after eclosion. Females from larvae that fed on plants of Salvinia molesta matured fewer oocytes (65 vs. 138) when the plants had lower (0·94% vs. 2·74%) levels of nitrogen. Resorbing oocytes were identified in the ovarioles of females 1–3 days old. The proportion of females with resorbing oocytes increased with age but not with larval dietary nutrition. Following high levels of larval dietary nitrogen, the seminal vesicles in males increased in length, while their width increased with age but not with diet. High levels of larval dietary nitrogen and an intake of adult dietary carbohydrate were both necessary for maximum fecundity. Higher levels of larval dietary nitrogen resulted in greater adult size, as measured by forewing length.