Sampling techniques and population estimation for Atherigona reversura Villenueve (Diptera:Muscidae) in bermudagrass hay fields McCullers, J.T. 1, Hudson, W.G.1 1Department of Entomology, University of Georgia, Athens,GA 30605

Atherigona reversura Villenueve (Diptera:Muscidae),  a member of the muscid shoot fly genus, was recently introduced into North America. First discovered in Georgia, the fly has the potential to become a substantial threat to bermudagrass hay fields through much of southern North America. Little is known about the fly and as a result effective control practices are unknown. In order to determine economic thresholds for treatment of the Bermuda grass shoot fly, various biotic and abiotic factors must be considered.  Among these, particular emphasis must be placed on mowing regimens, population density of adult flies, percentage of shoot damage and larval infestation, pupation period, as well as emergence success rate and synchronization. Over the summer of 2013, 9 bermudagrass hay fields from various locations in Georgia were evaluated through grass and fly samples taken in multiple 100 m² plots from each field. Grass samples were taken to the lab and assessed for grass density, overall height, and level of damage. After collection, larvae emerged from grass samples and pupated. These pupae were allowed to emerge in ventilated cups to determine the pupation period as well as the success rate and synchronization of the adult emergence. Data from the fly sampling techniques was used to create a formula in order to  estimate the population density of a given field. This estimate when considered with mowing regime, level of damage to the grass, and pupation period (due to the larval emergence from the cut grass and the subsequent surge in the adult population) can be used to assess when and if treatment is warranted.