The Indianmeal moth, Plodia interpunctella, is a serious pest on dried fruit and oil-rich food products, such as pet food, cereals, flour products, and candy bars. We examined the P. interpunctella oviposition on unscreened food dishes with whole-wheat kernels treated with one of 18 different oils diluted in hexane (oil-treated) compared with a second unscreened food dish with whole-wheat kernels treated with hexane only (control). For eight of the 18 oils, the same two-choice experiment was conducted with screened food dishes. We concluded that (1) total oviposition was significantly lower when food dishes were screened compared with experiments with unscreened dishes; (2) using unscreened food dishes, P. interpunctella females laid significantly more eggs in 17 types of oil-treated wheat compared with dishes with control wheat kernels; and (3) using screened food dishes, P. interpunctella females only laid significantly more eggs in walnut oil-treated wheat compared with dishes with control wheat kernels. A nine-choice experiment was conducted in a large arena with unscreened food dishes, in which one dish contained control wheat kernels and eight other food dishes contained wheat treated with different oils. In the nine-choice experiment, P. interpunctella females showed the strongest response to wheat kernels treated with oil from walnut. This study provides the basis for chemical identification of oviposition stimulants for P. interpunctella from food oils.
Annals of the Entomological Society of America
Vol. 96 • No. 4
Vol. 96 • No. 4