author(s)
Sunil Kayesth, Kamal Kumar Gupta

abstract
Antifeedant and Insecticidal properties of ethanol extracts of Catharanthus roseus, Ocimum sanctum, and Lantana camara were assessed by ‘seed dip method’ on Dysdercus koenigii. Significant differences were observed in the feeding response of fifth instar nymphs on seeds treated with the ethanol extract of Catharanthus roseus, Ocimum sanctum, and Lantana camara. It was reported that Ocimum sanctum, and Lantana camara extract were more effective than Catharanthus roseus in restraining the feeding. The effect of all the three extracts was dose dependent and in positive correlation with the concentration of the extracts. It was also reported that number of insects feeding on the extracts increased with time interval. This reflected possibility of the presence of antifeedant in the extracts. Although the cidal effects of the plant extracts were not much pronounced after 24 hr of exposure in all the three experimental plant extracts, a significant decrease in the survival of treated insects was observed specially during later part of their life. On seventh day of the exposure In comparison to Ocimum and Lantana, Catharanthus was most effective in reducing the percent survival of the treated fifth instars. Ethanol extracts of the plants also had impact on the longevity of the Dysdercus. There was reduction in the longevity of the treated nymphs and the adults developed from the treated fifth instar nymphs. The effects were most conspicuous with the Catharanthus.