The efficacy of several thiodicarb dosages (Larvin 350 RA) to control the soybean caterpillar, Anticarsia gemmatalis, was studied in Cruz Alta, Rio Grande do Sul State, during the 1989/90 cycle. A precision sprayer equipped with JD 10-1 conic nozzles, working at a constant pressure of 60 Ib/pol² and at a volume of 115 liters/ha of the suspension, was used to spray the insecticide treatments. The application of insecticides was made when the soybean plants (cv.Cobb) were one meter height, in the R1 growth stage, and the number of large larvae (>1.5cm) was between 43 and 46 per two meters of row. The number of live larvae at 0, 2, 4, 7 and 10 days after application, the defolation at 15 and 30 days after application and grain yield were the parameters evaluated. Results indicated that thiodicarb efficiently controled A gemmatalis caterpillars with dosages starting with 35g a.i./ha.
Anticarsia gemmatalis; chemical pest control; thiodicarb; soybean
