Biology and Stage Preference of Assassin Bug, Rhynocoris marginatus (Fabricius) (Heteroptera: Reduviidae) on Cutworm, Mythimna separata (Walker) a Pest of Cereal crops

The Cutworm, Mythimna separata (Walker), a serious pest of many cultivated crops was evaluated as prey for the reduviid predator, Rhynocoris marginatus Fab. The developmental duration, feeding potential and survival per cent of predator was investigated in the laboratory. Observations clearly indicated that the total developmental period of the predator were 72.9±1.56 days. The number of prey required for its development from egg to adult was 21.2±3.5 third instar larvae. Larval and adult survival was 60% on a diet of only M. seperata larvae. The fourth instar larvae were highly preferred (33.9%) followed by fifth (24.9%) and third (22.0%) instars. First and second instar larvae were least preferred. The predator offers great bio-control potential for management of cutworms in multi crop ecosystems.