COMPARISON OF SOYBEAN LOOPER (LEPIDOPTERA: NOCTUIDAE) POPULATIONS IN SOYBEAN AND COTTON/SOYBEAN AGROECOSYSTEMS

Abstract

During 3 years, soybean fields in southern Georgia were sampled for larval soybean looper (SBL), Pseudoplusia includens Walker. Soybean fields were sampled from 2 area types: areas in which cotton and soybean were both grown and areas where soybean was grown in the absence of cotton. Average larval density during the 3-year period ranged from 0.5 to 93.9 larvae/50 sweeps in cotton + soybean areas and from 0.0 to 7.1 larvae/50 sweeps in soybean only areas. Populations of SBL larvae were significantly (P=0.05) greater on soybean in cotton + soybean areas as opposed to soybean only areas on the majority of sample dates over the 3 year study. Results of surveys indicate that soybean fields planted near cotton fields are at greater risk of experiencing economically injurious populations of SBL larvae.