The Effects of Early Diet on Survival and Reproduction at Older Ages in Two Tephritid Fruit Flies

Abstract

Agricultural ecosystems maintain predictable resource distributions, although dietary resources are not evenly distributed within the environment naturally. The goal of this project was to determine how well melon fly (Tephritidae: Bactrocera cucurbitae) and oriental fruit fly (Tephritidae: Bactrocera dorsalis) adults respond to unreliable resource availability by varying the sequence in which the flies received a full (3:1 yeast to sugar) or a sugar-only diet. For each of the nine sequence treatments, there were three ten-day dietary periods beginning at emergence, during which the flies received either a full diet or a sugar-only diet. The fourth dietary period, full diet only, lasted from day thirty until the end of life. To measure reproduction, oviposition sites were made available for twenty days starting at the beginning of the fourth period. Three main results emerged from this study. First, the survival consequences of a poor diet are greatest for young flies (10 days). Second, the death rate dropped for both species when older flies received a full diet after having access to a sugar-only diet. Third, the amount of full diet had a larger effect on fecundity than the sequence, with the response different for the two species. The differing response of each species to the dietary restriction is likely due to life history characteristics