Parallel changes in enzyme activity and oviposition behavior in adults ofDrosophila melanogastersubmitted to alcohols, acetaldehyde or acetone

Abstract

Two geographic populations of D. melanogaster, French and African, whic.. differ in their frequencies at the Adh locus and their ethanol tolerance, were tested for their oviposition site preference, mortality and activities of two enzymes involved in alcohol metabolism. To investigate the oviposition choice towards ethanol, 2-propanol, acetaldehyde et acetone, females of the two populations of D. melanogaster were exposed to a choice situation opposing a medium free-alcohol to a medium supplemented with one of the tested compounds. We noticed that the avoidance of media containing one the two studied alcohols, acetaldehyde or acetone, increased during the experiment.The most repellent medium for ovipositing females was that supplemented with 2-propanol or acetone. Besides, the study of female mortality on attractant or repellent media revealed that the most repulsive media were also the most lethal. Moreover, the treatment with ethanol, 2-propanol, acetaldehyde or acetone led to a reduction in alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) activities. A strong inhibition of ADH occurs (78.57%) in females a few days after the treatement with the tested products. Compared to ADH activity, ALDH activity was less reduced (5 1.78%). We suggest that fly mortality and the fly's aversion to alcoholic media might be linked to the decline of ADH and ALDH activities. The toxic effects of the used compounds appear more clearly in African flies than in French ones.

Olfactory attraction of Drosophila suzukii by symbiotic acetic acid bacteria

“…Mean percentages (±SE) on the right report flies that did not choose either the control or the strain. Asterisks indicate significant differences between the number of flies that chose the control and the strain according to the Friedman-ANOVA and Wilcoxon signed-rank tests with a Bonferroni correction (P \ 0.05) factor after 48 h. The role of 2-propanone is quite controversial: although this compound is reported to be a repellant for vinegar flies (Elamrani et al 2001), Riveron et al (2009) showed that 2-propanone can be repellent or attractive to D. melanogaster according to its concentration. Moreover, Newby and Etges (1998) reported that 2-propanone is a general attractant to D. mojavensis and can engender increased adult longevity.…”

Identification of Blackberry (Rubus fruticosus) Volatiles as Drosophila suzukii Attractants

“…Acetaldehyde is a known fruit fermentation product, originating as an intermediate in the conversion of ethanol to acetic acid [ 46 ]. Both acetaldehyde and limonene are known to be attractive to Drosophila melanogaster [ 47 , 48 ]. However, as yet, their attractive effect had not been demonstrated for D. suzukii.…”