Hatching time (the period between egg-laying and hatching) and emerging time were surveyed and their relationship with the adult life span was investigated. A relationship between emerging time and adult life span was clearly evident: early emergers were often long-lived. This relation is considered to have a genetic basis because all the larvae in a group were bred in the same culture bottle. Thus, the longevity genes involved also appear to have control over the rate of development. No significant relation was observed between hatching time and adult life span or between hatching time and emerging time. These results suggest that the function of the longevity genes begins at the larval or pupal stage before emergence, and that adult life spans differentiate at this time.