Hunting billbugs (Sphenophorus venatus vestitus) cause damage to zoysiagrass and bermudagrass. Damage is often misdiagnosed as either drought, dormancy, chinch bug or white grub feeding, or even one of several disease infections. Increasingly higher populations of this billbug have been observed over the past 10 to 15 years and it is often responsible for extensive turf damage or loss of sod production in both zoysiagrass and bermudagrass.
This experiment was established to evaluate nine zoysiagrass (Zoysia spp.) cultivars for resistance. Field cages (8 ft. diam.) were used to confine adults of the hunting billbug in a paired cage split-plot experiment with 4 reps, so treated plants could be directly compared with untreated paired plants. Plants were established and billbugs introduced in mid June 2000. Surface growth and damage was evaluated by ranking each test plant on a scale of 1 to 9 (1=severe damage, 9=no damage). To measure the damage to the roots and rhizomes, all plants were harvested and bagged in late Sept. 2000 by excavating the entire plant from the sand. Total rhizome and stolon length was measured and total plant biomass was collected, oven dried and weighed. Solons and rhizomes from each treated plant were also evaluated for feeding damage. Resistance was identified in four cultivars of Zoysia matrella (Diamond, DALZ9601, Cavalier and Royal). Meyer (the industry standard) has now been documented as highly susceptible to zoysiagrass mite, fall armyworm, tropical sod webworm, tawny mole cricket, differential grasshopper and hunting billbug. This data provides the first documented report of resistance to the hunting billbug in Zoysia.
Species 1: Coleoptera Curculionidae Sphenophorus venatus vestitus (hunting billbug)
Keywords: Host Preference, Host Plant Resistance
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA