Evaluation of the Attractant Effect of Solanum muricatum (Solanales: Solanaceae) on Gravid Female Adults of Zeugodacus tau (Diptera: Tephritidae) and Screening of Attractant Volatiles

Simple SummaryThe Solanaceae crops are the main hosts ofZeugodacus tau, a pest insect that causes serious damage to economically important crops of Solanaceae. In the winter–spring period, female adults ofZ. tauhave been found to oviposit on the pepino melonSolanum muricatum. However, the differences in the ability of the fruits ofS. muricatumand other Solanaceae crops to attract gravidZ. taufemales have not been clarified. In this study, oviposition and trapping bioassays were performed to clarify whether such differences existed. GC-MS was used to identify the compounds and relative contents of the volatile odors ofS. muricatum. The Y-tube olfactometer system was used to determine the compounds that induced behavioral responses in gravidZ. taufemales. The results show thatSolanum muricatumodor was attractive forZ. taufemales. The nine compounds from the volatiles ofS. muricatuminduce behavioral responses in gravidZ. taufemales. These results are beneficial for preventingZ. taufemales from harmingS. muricatum, developing attractants and repellents forZ. taufemales, and establishing a system of ecological control forZ. taufemales.AbstractZeugodacus tau(Walker) (Diptera: Tephritidae) is a pest seriously harmful to Solanaceae crops and was found to oviposit on the pepino melonSolanum muricatum(Aiton). To date, the differences in the ability of the fruits ofS. muricatumand other Solanaceae crops to attract gravidZ. taufemales have seldom been reported. Oviposition and trapping bioassays were performed to clarify whether such differences existed. A combination of GC-MS and the Y-tube olfactometer system was used to identify and determine the compounds inducing behavioral responses in gravidZ. taufemales to the volatile odors ofS. muricatum. The results show thatS. muricatumodors play a role in attracting gravidZ. taufemales. The odors of Solanaceae crops influence their ability to attract these organisms. The nine compounds from the volatiles ofS. muricatuminduce tendency or repellency responses in gravidZ. taufemales. Hexyl acetate, butyl acetate, amyl actate, and isoamyl acetate caused tendency behavior in gravidZ. taufemales, while hexyl hexanoate, butyl isovalerate, butyl valerate, and isoamyl hexanoate caused repellency behavior. Heptyl acetate caused repellency behavior in gravidZ. taufemales at higher concentrations (5 mg/mL) but caused tendency behavior at a low concentration (0.5 mg/mL). These results suggest that vigilance against the harm caused byZ. tauis required during the cultivation ofS. muricatum. The nine compounds of the volatile odors ofS. muricatumcould help to develop attractants and repellents for gravidZ. taufemales. These results are beneficial for preventingZ. taufemales from harmingS. muricatum, developing attractants and repellents forZ. taufemales, and establishing a system of ecological control forZ. taufemales.Keywords:Zeugodacus tau;Solanum muricatum;induced oviposition;attraction rate;volatile