ENDOPHYTE-ENHANCED RESISTANCE TO BILLBUG (COLEOPTERA, CURCULIONIDAE), SOD WEBWORM (LEPIDOPTERA, PYRALIDAE), AND WHITE GRUB (COLEOPTERA, SCARABEIDAE) IN TALL FESCUE

The species complex of billbugs (Sphenophorus spp.) is more complicated and may cause more damage to turfgrass than previously documented. The influence of endophyte infection on billbug feeding damage was examined in two tall fescue (Festuca arundinacea Schreber) field trials in New Jersey. Before insect damage, endophyte infection in tall fescue had no marked influence on overall turf quality. Billbug feeding damage reduced turf cover by as much as 25% in endophyte-free tall fescue. Two billbug species, S. venatus vestitus Chittenden and S. minimus Hart, accounted for 94% of the adults collected from the two trials; S. venatus vestitus accounted for 73% of the adults. Active larvae feeding during fall and early winter demonstrated that a second generation of billbug (S. venatus vestitus) occurred in New Jersey in 1991. Two additional types of turfgrass pests, sod webworms (Lepidoptera: Pyralidae) and scarabeid grubs, were observed in these two field trials. Sod webworm population was lowest in endopbyte-infected tall fescue of both trials whereas grub population was only significantly lower in endophyte-infected plots of one trial. The results from this field study indicate that a species complex of insect pests, and in particular billbug, can be a serious problem in endophyte-free tall fescue turf and that endophyte infection is important for enhancing a high level of resistance to insect damage. The demonstration of serious insect feeding damage to tall fescue further emphasizes the importance of host resistance, whether through endophyte enhancement or ''true'' host resistance.