Adaptation to alcoholic fermentation in Drosophila species: Relationship between alcohol tolerance and larval habitat

Abstract

1. 1. According to their main larval habitat and their ecological relationship with alcoholic fermentation, Drosophila species can be classified into three groups: species using artificial, man-made fermentations are highly tolerant to ethanol (average LC 50 of 18.7% of ethanol); species breeding in fermenting fruits show a medium but significant tolerance (average 3.5%); species breeding in nonfermenting resources are ethanol sensitive (average 1.8%). 2. 2. All species, even the most sensitive, have an active alcohol dehydrogenase and can metabolize small concentrations of alcohol. Moreover, some overlap exist between the two last groups: some fruit breeding species are ethanol sensitive while others, growing in non-fermenting substrates, present a significant tolerance to ethanol. 3. 3. From these comparative results, it may be concluded that the level of ethanol tolerance in Drosophila species cannot be entirely explained by their adaptation to alcoholic resources. © 1983.