Abstract: 【Aim】 To explore the effects of propionic and butyric acids on the oviposition preference of Drosophila melanogaster, and to provide an insight into its biological significance. 【Methods】 The 2-choice apparatus was employed to assess the oviposition selection of D. melanogaster female adults. The flies with the acid-sensing gustatory receptors eliminated or the olfactory antennae surgically removed were used to investigate the oviposition-associated sensory system. The developmental duration and survival rate of the fruit fly were utilized to evaluate the biological significance of oviposition avoidance of D. melanogaster to propionic acid. 【Results】 D. melanogaster female adults displayed an oviposition avoidance to propionic and butyric acids in a dosage-ependent manner. The oviposition avoidance of IR64a and IR76b mutants to 0.5% propionic acid was completely impaired with the oviposition index of -0.07 and -0.17, respectively. The female adults repelled human feces to oviposit with the oviposition index of -0.7--0.9, which may be explained by a balanced decision to the attractiveness to acetic acid and the avoidance to propionic acid. IR64a and IR76b mutants showed less oviposition avoidance to human feces with the oviposition index of -0.49 and -0.38, respectively. Propionic acid dramatically delayed the developmental duration of their progeny and reduced the survival rate in a dosage-dependent manner, and 2% propionic acid caused death of larvae. 【Conclusion】 D. melanogaster female adults repel to lay eggs on food with propionic acid through the olfactory system, and this behavior promotes the development of D. melanogaster larvae and boosts the survival rate of their offspring.

Key words: Drosophila melanogaster, oviposition avoidance, propionic acid, human feces, velopmental duration, survival rate