Evaluation of reduviid predators and plant products against chosen groundnut pests

Abstract

The augmentative release of a reduviid predator Rhynocoris kumraii Ambrose and Livingstone (Heteroptera: Reduviidae), hot water extract of Ipomea cornea Jacq. (Family Convvolulaceae) and Vitex negundo Linn. (Family Verbenaceae) were evaluated against selected groundnut pests at farmers field in Tamil Nadu, India. The results revealed that invariably endosilfan highly reduce all the pest populations. Aphis craccivora (Koch) (Hemiptera: Aphididae) population was highly reduced by the combination of both plant extracts in equal proportion (54.40%) followed by I. cornea (48.86%) and V. negundo (37.85%). Similar observation were also observed for Helicoverpa armigera Hubner (Lepidoptera: Noctudidae) and Spodoptera litura (Fab.) (Lepidoptera: Noctudidae). Both the plants have very limited impact on grasshoppers such as C. trachyterus and A. crenulata. Rhynocoris kumraii highly reduce S. litura followed by A. craccivora, H. armigera, Chrotogonus trachyterus Blanch and Atractomorpha crenulata Fab. But the reduviid predator has the ability to suppress Mylabris pustulata. Among all the treatments tested, groundnut production was higher in Rhynocoris kumraii released field followed by endosulfan and the combination of both plant extracts in equal proportion sprayed plot. In general, all the treatments invariably reduce the pest populations and increase the groundnut production and hence they can be utilized and incorporated in the groundnut pests' managements.

Keywords:

• Reduviid predator
• plant products
• groundnut pests
• groundnut production

Acknowledgements

The first author (KSR) is highly thankful to Rev. Fr. A. Antonysamy, S.J., Principal, and Prof. M. Thomas Punithan, Head of Department of Advanced Zoology and Biotechnology at St Xavier's College (Autonomous), Palayamkottai, for providing the necessary laboratory facilities and encouragement.