Evaluation of insecticides against the cutworm Agrotis ipsilon Hubn. in onion

摘要

In recent years the cutworm, Agrotis ipsilon Hubner has been a major problem on irrigated onion in Tamil Nadu where it occurs rather sporadiclly. Srivastava and Pandey (1968) observed A. ipsilion on onion for the first time in India at Udaipur in Rajasthan. Bharadwaj et al. (1983) recorded A. ipsilon on the Bellary onion Allium cepa var. cepa L. in both the nursery and field. The cutworm larvae remain either in between the bulbs or in the soil near the roots. The infestation is rather hidden until the leaves wither and fall. Young plants are more susceptible to cutworm attack than older onions (Srivastava and Pandey, 1968). Early instar larvae enter the tubular leaves and scrape the tissues from inside, while mature caterpillars cut off the leaves.Since no information is available from Tamil Nadu, this investigation was made to study the effect of pesticides on A. ipsilon.