This work was carried out in 1989/90 crop growing season, in Cruz Alta, Rio Grande do Sul State, using results of five field experiments. The objective was to evaluate the effect of the nuclear polyhedrosis virus (NPV), Baculovirus anticarsia, associated with low dosage of insecticides in the control of soybean caterpillar, Anticarsia gemmatalis (Hübner), when the populadon exceeds the limits to apply the virus alone. The parameters evaluated were number of living larvae, number of larvae cadavers, percentage defolation and grain yield. Results indicated that the NPV associated with low dosage of diflubenzuron (1.25g a.i./ha), carbaryl (48g a.i./ha), chlorpyriphos (36g a.i./ha), endosulfan (35g a.i./ha), permethrin (3g a.i./ha), profenophos (25g a.i./ha), thiodicarb (17.5g a.i./ha) and tricholrphon (200g a.i./ha) was as efficient as diflubenzuron (15g a.i/ha), carbaryl (200g a.i/ha.), chlorpyriphos (180g a.i./ha). endosulfan (175g a.i./ha), permethrin (15g a.i./ha), profenophos (100g a.i/ha), thiodicarb (70g a.i./ha) and trichlorphon (400g a.i/ha) at full dosage in the control of the large populations of the soybean caterpillar. The NPV associated with low dosage of Bacillus thuringlensis (125g c.p./ha) and the use of full dosage of B. thuringlensis (500g c.p./ha) were not efficient.
insects; nuclear polyhedrosis; biological control; chemical control; soybean
