Abstract
The effects of larval density on larval and pupal development, adult longevity and oviposition of the melon fly, Dacus cucurbitae COQUILETT, were examined. The average body weight of pupa and pupation rate decreased with the increase of larval density. The larval density did not affect emergence rate. Small pupae emerged slightly earlier than large ones. Adult longevity of flies reared at the high larval density was slightly shorter than that of flies reared at the low larval density, and the decrease of fecundity of the former was slight. Fecundity of the former was about 60% of that of the latter though body weight was only one fourth. Even if the larval density is excessively high, the melon fly can reproduce next generation flies sufficiently since the body size becomes small and the small fly oviposits sufficiently.
