Exposure to essential oils and ethanol vapors affect fecundity and survival of two frugivorous fruit fly (Diptera: Tephritidae) pest species.

Plant-derived compounds can be an environmentally friendly alternative to synthetic pesticide use for pest management. Essential oils (EOs) in several plant families have been found to be toxic to various pest species of insects through topical application, ingestion, and as fumigants. Previous studies revealed that, among various environmentally friendly insecticides, the EOs ofBaccharis dracunculifoliaandPinus elliottiiand an ethanol extract ofSolanum granulosoleprosumplusRicinus communis, were toxic toCeratitis capitataandAnastrepha fraterculus(Diptera: Tephritidae) when applied topically to pupae or when ingested by adults. Here, we aimed to examine the potentially toxic effects of these plant-derived compounds when these two pestiferous fruit fly species were exposed to their vapors. We also examined their fumigant effect on female fecundity and fertility and compared it with water and ethanol controls. Exposure ofC. capitataandA. fraterculussexually mature adults to volatiles and vapors of bothB. dracunculifoliaandP. elliottiiEOs resulted in lower longevity (half-life), survivorship, and female fecundity than the water vapor control. Toxicity ofC. capitatawas greater forP. elliottiithan forB. dracunculifoliawhile the reverse was true forA. fraterculus.Exposure to vapors ofS. granulosoleprosum + R. communis(S + R) had no effect on longevity but reduced survivorship of adults of both species. Interestingly, exposure to vapors of S + R, 50% (v/v) and pure ethanol resulted in greater fecundity of females of both frugivorous fly species than the water control. By contrast, fertility (% egg hatch) was in all cases high (>85%) and not different than the water control. Exposure to ethanol vapors appears to have similar effects on frugivorous tephritids as those reported on saprophagous and frugivorous species ofDrosophila, a novel finding that may have important practical implications.