Alcohol dehydrogenase allele frequencies in Bactrocera oleae (Dipt., Tephritidae): effect of ethanol addition in larval diet

Abstract: The effect of ethanol in larval medium on Bactrocera oleae larvae was examined at four concentrations. Ethanol exerted a differential effect on the three alcohol dehydrogenase allele frequencies. While originally being at equilibrium under laboratory conditions, after three generations of larval development in a diet containing ethanol at 1% concentration, Adh -F allele frequency increased, that of Adh -I dropped significantly and the frequency of Adh -S remained unaltered. Adh -S allele seems to be adapted in nature where only minor quantities of alcohol are present in the insects' natural host, while Adh -I is best adapted in the alcohol-free laboratory culture medium. The frequency of Adh -F allele remains unaltered when feral populations are introduced in the laboratory.