Flights of Noctuidae and Crambidae of economic importance in Southeast Missouri - 2015, 2016

Growers of cotton and soybean in Southeast Missouri have expressed deep concern over increases in lepidopteran damage the past 2 years. Efforts to control fall armyworm, bollworm, Southwestern corn borer, and black cutworm with Bt varieties of corn or cotton and foliar insecticides generally meet with limited success. Therefore, we sought a more effective means to monitor and manage these moth populations in cotton, soybean, corn, and grain sorghum by use of pheromone traps and verification of degree-day models. Green plastic funnel traps baited with their respective lures were dispensed and monitored weekly (1 May - 1 Oct 2015, 2016) in 8 randomly selected soybean and cotton fields. Degree-days began at biofix, and a single sine method with lower and upper thresholds were used for the model. Temperature data were obtained from National Oceanic and Atmospheric Administration (NOAA). Each moth peak was assigned accumulative number of degree-days. Accumulated degree-day sums for peak flight of each moth species were estimated by averaging accumulated degree-days between counties for peaks 1-5. For direct comparison, interpretation, and incorporation into a predictive model, differences between the degree-days that flight actually occurred and predictions from models were evaluated with analysis of variance. Factors in the model were county, flight/model, peak, and degree-days. No significant differences in degree-days were found between the peak-flight in degree-days, and the degree-days of its model for the respective moth species, regardless of county. These models are a good fit for predicting catches of moths in monitoring traps and management decisions for Southeast Missouri.