The influence of sprinkler irrigation on dispersal of nuclear polyhedrosis virus (NPV) in remains of NPV-killed lepidopterous larvae on soybean was examined.Anticarsia gemmatalisHübner andPseudoplusia includens(Walker) larvae in late stages of infection with their respective NPV isolates were placed on separate rows in the upper canopy of caged soybean plants. After death of the infected larvae, the cages were removed, and the plants were immediately irrigated by sprinkler. Leaflets were collected and bioassayed for NPV with second instars of the respective host. Dispersal of NPVs from cadaver remnants on the plants occurred without irrigation but was significantly increased by 0.25 cm water from sprinkler irrigation. The majority of each NPV was moved into the lower canopy (P<0.05). Additional irrigation totaling 1.25 or 6.25 cm did not significantly increase dispersal of theP. includensNPV but did increaseA. gemmatalisNPV in the lower canopy. Virus dispersal was less affected when irrigation was delayed until 7 d after larval death. However, the highest volume (6.25 cm) resulted in significantly higher larval mortality in the irrigated plots (P<0.05).