SOYBEAN FOLIAGE CONSUMPTION BY PSEUDOPLUSIA INCLUDENS (WALKER) (LEPIDOPTERA: NOCTUIDAE) LARVAE INFECTED WITH NUCLEAR POLYHEDROSIS VIRUS1,2

Consumption of greenhouse and field grown ‘Bragg’ soybean, Glycine max (L.) Merrill, foliage was determined for Pseudoplusia includens (Walker) larvae treated with varying dosages of Pseudoplusia nuclear polyhedrosis virus to produce different mortality levels. Uninfected P. includens larvae consumed an average of 158.3 and 78.7 cm2 of greenhouse and field grown soybean foliage, respectively. More than 84% of the total leaf area consumed was by the final two larval instars. The amount of foliage consumed by larvae infected as first (greenhouse and field) or second (greenhouse) instars was significantly reduced with increasing NPV mortality level. Foliage consumption by larvae infected as second (field) and third (greenhouse and field) instars at all dosage levels was significantly reduced when compared to the untreated checks, but differences in foliage consumption at the two lower mortality levels were not significant. Frass produced by infected and uninfected larvae was significantly correlated with the amount of greenhouse or field grown foliage consumed.