Monday, December 10, 2007 - 8:41 AM

Habitat exploitation by the annual bluegrass weevil, Listronotus maculicollis (Coleoptera, Curculionidae), in golf course turf: Interpreting the link between damage prevalence and population distribution

Masanori Seto, ms545@cornell.edu1, Maria Derval Diaz, maria.diaz@ars.usda.gov2, and Daniel C. Peck, dp25@cornell.edu1. (1) Cornell University, Department of Entomology, New York State Agricultural Experiment Station, 630 West North Street, Geneva, NY, (2) USDA-ARS, 64 Nowelo St, Hilo, HI

On golf courses, damage from the annual bluegrass weevil is most expressed at the edge of short-mown turf. More insects and more susceptible hosts are competing explanations, but they are coupled to other interactions such as abundance of natural enemies, host plant density and habitat preferences. To better understand patterns of habitat exploitation, data on population dynamics were collected over three years along transects laid across fairways and bordering rough of two representative golf courses in upstate NY. From the rough to the fairway, M:F sex ratio shifted from 1.7 to 1.0 and insect abundance increased up to 6.9 times. Within the fairway itself, larval and adult distributions were similar. Although immigrating adults first colonized the edge, populations quickly became uniform across the width of the fairway. This pattern was consistent among years and between sites. Therefore, the prevalence of damage on the edge was not caused by higher insect densities. To interpret this scenario with respect to insect load (insects/host), a detailed geospatial study was conducted at one site in 2007. Abundance of insect developmental stages, injury rating, and grass species composition were recorded at each of forty-nine plots over the season. Initial analyses revealed that host plant density was also uniform across the fairway and, despite nearly 20-fold increase in densities compared to previous years, the pattern of damage prevalence and insect distribution was similar. Given that insect load was also uniform across the fairway, damage prevalence at the edge may be linked to host plant susceptibility.

Species 1: Coleoptera Curculionidae Listronotus maculicollis (annual bluegrass weevil)