Degree-day model to predict the phenology of the annual bluegrass weevil, Listronotus maculicollis (Coleoptera: Curculionidae), in golf course landscapes

The annual bluegrass weevil is a damaging pest in high maintenance annual bluegrass turf of the Northeast U.S. Poor targeting of insecticidal controls in time severely hamper management efforts. We therefore tested the hypothesis that across the Northeast, the timing of adult movement in the spring and the peak occurrence of the different developmental stages are linked by a common degree-day model. Population data were collected weekly from two golf courses over three consecutive field seasons (2004-2006). Larvae were identified to instar and adults to male/female and callow/mature. The data were used to develop models based on degree-day accumulations to predict the timing of the appearance of life stages. The best model was further tested in a validation study across several sites in New York. The anticipated result is a sufficiently robust and precise degree-day model that complements or supersedes the current reliance on phenological plant predictors and calendar date. As new intervention tactics (insecticidal, biological or cultural) are developed, this model will be useful for targeting the susceptible developmental stages in time.