Trap cropping efficacy of an alternate host Physalis angulata against brinjal hadda beetle Epilachna vigintioctopunctata (Coccinellidae: Coleoptera
A Isaianbu and P Manikandan
Eggplant or brinjal is one of the most important vegetable crops cultivated in tropical and sub-tropical countries of the world. Insect pests are the major biotic factor which leads up to 21 % yield loss. Among them hadda beetle- Epilachna vigintioctopunctata (Coccinellidae: Coleoptera) is the major defoliator causing heavy yield loss. It is a polyphagous pest feeding on wide host range. Due to its multiple host range, this pest occurs throughout the year. Using trap crops in pest management is one of the important components of IPM. Many alternate hosts of crop pests support their survivability and some of the alternate hosts attract the pest than the crop. To know the preferred alternate hosts of hadda beetle field, a survey was conducted for the year 2017-2018. Following hosts were recorded with a considerable level of hadda beetle incidence in the field such as Datura metal, Solanum xanthocarpum, Physalis angulata, Solanum nigrum and Solanum trilobatum. Net cage and laboratory evaluation resulted that the hierarchy of preference towards different alternate hosts was P. angulata > S. nigrum> D. metal > S. trilobatum> S. xanthocarpum. The highly preferred host P. angulata was evaluated for its trap cropping efficacy along with brinjal under net cage condition and the results showed the highest oviposition on P. angulata during the entire study period. The number of grubs and feeding damage were recorded on P. angulata than the brinjal up to 90 days after release.