Impact of Augmentative Release of Rhynocoris kumarii Ambrose & Livingstone (Heteroptera: Reduviidae) on Dysdercus cingulatus (Fabricius) (Hemiptera: Pyrrhocoridae) Population and Damage on Cotton

Abstract

An attempt was made to augment Rhynocoris kumarii Ambrose and Livingstone in a cotton field to suppress Dysdercus cingulatus (Fabricius). The first release of adult stage of R. kumarii did not affect the number of adult D. cingulatus in the released and control field plots. The second release of R. kumarii in egg stage also did not significantly affect the number of first instar D. cingulatus. The third release of R. kumarii in III instar did not affect the number of II and III nymphal instars of D. cingulatus. However, after the fourth release of V instar stage of R. kumarii there was significantly fewer IV, V and adult D. cingulatus in predator released plots compared to non-released (control) plots. Plant damage by D. cingulatus was less severe in predator released plots than in non-released control plots. There was no difference in the number of predatory arthropods, such as Menocholis sp., Orius sp., Geocoris sp., Cantheconidia sp., Rhynocoris fusciepes, Mantis sp. and spiders found in released and non-released field plots. The percentage of good quality cotton and yield of seed-cotton was greater in released plots tllan in non-released control plots.