It has been reported that billbug (Sphenophorus sp.) damage is most apparent in turfgrass already suffering from abiotic stress1. Drought tolerant turfgrass cultivars are available to alleviate water-stress in regions where water is increasingly limited. However, an understanding of the interplay between water stress and billbug stress is needed to assist managers in suppressing pests while implementing water-wise programs. To this end, we reviewed National Turf Evaluation Program (NTEP) data to determine if drought tolerance and billbug resistance correlate. We also used choice assays and survey data to characterize adult bluegrass billbug (S. parvulus) selection of Kentucky bluegrass (KBG) cultivars under different irrigation regimes. In survey data we found significantly greater adult billbug abundance in areas with lower soil moisture. We also found evidence of billbug discrimination between different Kentucky bluegrass (KBG) cultivars. However, this discrimination did not appear to be driven by drought tolerance and billbugs showed no significant preference for water-limited or well-watered plants. These results suggest that, though water limitation may play a role in determining localized billbug abundance, this is not due to adult billbug preferences for drought susceptible or drought-stressed host plants. Future studies should examine other mechanisms (such as larval survivorship) that may explain differential billbug damage and abundance in relation to water availability.
