Quantifying the Damage Potential of the Bermudagrass Stem Maggot

Abstract

Since its 2010 discovery in southern Georgia, the bermudagrass stem maggot (BSM, Atherigona reversura Villenueve) has spread throughout the southeastern United States, damaging bermudagrass [Cynodon dactylon (L.) Pers.] hayfields and pastures. The objective of this research was to quantify the damage potential of the BSM in terms of forage accumulation, nutritive value, and economic returns from five bermudagrass varieties grown in Tifton, GA. The BSM significantly reduced accumulated forage only from late July to September in each year of this study. This would generally correspond to the third, fourth, and/or fifth harvest of the year for bermudagrass hay producers in the states of the Deep South. When BSM damage affected accumulated forage, crude protein increased while other nutritive value parameters decreased in plots not treated with insecticide. The results indicate that spraying prior to every harvest is not an economical management strategy. Instead, insecticide applications should only be made when significant forage loss is expected (generally from late July to September). Producers should create and implement a strategic integrated pest management plan to manage BSM populations on their farms to ensure positive economic returns and slow the potential resistance of the BSM to pyrethroids by preventing their overuse.