The Influence of Low Temperature on Survival and Reproduction in Populations of Drosophila Melanogaster.

Abstract

Observations in the cellar at the 'Chateau Tahbilk' vineyard in Victoria demonstrate that while adults of D. melanogaster can be collected throughout the year, larvae and pupae are not found when the temperature is less than 13ºC. Laboratory studies confirm that the amount of mating and oviposition of this species is restricted in the vicinity of this temperature. Field experiments indicate that during winter the survival probability of adults is greater than the developmental probability of larvae and pupae, and that the population may be reconstituted during spring by overwintering adults, most probably inseminated females. These results show how adaptive modification in the pattern of a life cycle may be evolved by selection under conditions of extreme environment.