Detection of parasitized rice weevils in wheat kernels with near-infrared spectroscopy

Individual kernels of wheat containing immature rice weevils, Sitophilus or yzae (L.) (Coleoptera: Curculionidae), parasitized by Anisopteromalus calan drae (Howard) (Hymenoptera: Pteromalidae) could be separated from uninfeste d kernels and kernels that contained unparasitized weevils by using near-in frared (NIR) spectroscopy. Wheat kernels from cultures of the parasitoid we re X-rayed and sorted into uninfested kernels, kernels infested with weevil larvae or pupae, kernels containing parasitoid larvae feeding on host weev ils, and kernels containing parasitoid pupae and remains of the host. Kerne ls were automatically positioned and scanned (400-1700 nm) with the NIR sys tem. Kernels containing parasitoid pupae mere completely differentiated fro m kernels containing weevil pupae as web as all other kernels in this autom ated system. With the appropriate integration of NIR spectroscopy and seed- sorting instrumentation, kernels containing parasitoid pupae could be autom atically collected from cultures of A. calandrae during the mass rearing of this beneficial insect.