Tripsacum dactyloides (Graminae) seedlings for host plant resistance to the western corn rootworm (Coleoptera: Chrysomelidae)

Mature plants and cuttings of Tripsacum dactyloides (L.) have shown resistance to western corn rootworm, Diabrotica virgifera virgifera LeConte, larvae. The purpose of our study was to evaluate seedling-stage T. dactyloides for resistance to western corn rootworm larvae. Two evaluations were conducted using 50- to 56-d-old T. dactyloides seedlings and maize, Zea mays L., checks. In the 1st evaluation, rootworm larvae, 4, 5, and 6 wk after infestation, weighed significantly less than feeding on T. dactyloides when compared with larvae feeding on the maize checks. In the 2nd evaluation, only 3 larvae were found on a total of 20 T. dactyloides seedlings, whereas the susceptible maize controls averaged >1 larva per plant. These results indicate the presence of corn rootworm resistance in T. dactyloides seedlings that may be transferable into commercial maize.