Abstract Selected microbial insecticides (Biobit, Condor, Dipel ES, Agree, Javelin, EXP 60516A and Delta Bt) were evaluated for efficacy against the soybean looper. Soybeans were planted 3 Jun on a Sharkey clay soil at the Northeast Research Station, St. Joseph, LA. Plots were 19.82 m X 4 rows (1.02 m row spacing), replicated 4 times in a randomized complete block design. Test treatments were applied with a tractor mounted boom equipped with a compressed air system for spraying small plots. Spray volume was calibrated to deliver 93.5 liters/ha with two 80015 fiat fan nozzles/row. Application was to all 4 rows of the plots on 23 Aug. The soybeans were in the R5 growth stage at the time of application. Fifty sweep samples per plot were taken at 3 and 6 DAT using a 38.2 cm diam sweep net. Rainfall amounts were 0.31 inch on 22 Aug, 0.28 inch on 26 Aug and 0.31 inch on 28 Aug.