Effect of Anticarsia baculoyirus dosages on soybean foliar consumption and utilization by larvae of Anticarsia gemmatalis Hübner (Lepidoptera: Noctuidae)

Abstract

Baculovirus anticarsia (NPV), at 0.5, 2.7, 15 and 80 polyhedron inclusion bodies (PIB)/mm2 of soybean leaf surface, was evaluated on velvetbean caterpillar (VBC) (Anticarsia gemmatalis Habner) to determine the effect of doses on VBC food consumption and utilization. All doses significantly reduced the foliar consumption by VBC, when compared to healthy larvae. At 80 PIB/mm² larvae presented significant lower consumption and shorter feeding period in relation to other dosages. The beginning of feeding reduction occurred at the second day (80 PIB/mm²) or at the fourth day (other doses) after infection. The weights of digested food, of larvae, and of produced feces showed similar relationships to those observed for foliar consumption. The efficiency of conversion of ingested food (ECI) and of conversion of digested food (ECD) were altered significantly by the pathogen, but these parameters did not present a clear relationship with the virus dosages.