Studies on ovicidal effects of some plant extracts against the diamondback moth, Plutella xylostella (L.) infesting cauliflower crop.

Studies on ovicidal effects of aqueous and alcoholic extracts of four different plants namely, Melia azedarach; Lantana camara, Artemisia annua and Cannabis sativa were carried out under laboratory conditions against the diamondback moth, Plutella xylostella (L.) which revealed that extracts of all the plants used had significant effect on the mortality of eggs. However, the alcoholic extracts were found to be better than the aqueous extracts. Alcoholic and aqueous extracts of M. azedarach (leaf) resulted in mean egg hatch of 24.4 per cent and 59.9 per cent at 10 per cent concentration in comparison to control where 90.0 and 88.3 per cent egg hatch was observed. This was followed by A. annua seed extract where the same concentration resulted in 31.1 per cent and 77.7 per cent egg hatch in alcoholic and aqueous extracts respectively. L. camara (seed) and C. sativa (leaf) extracts were followed by these with 64.4 and 75.5 per cent eggs hatch in case of alcoholic extract and 73.2 and 82.2 per cent egg hatch in case of aqueous extract. There was constant increase in the per cent kill of egg masses with the increase in the extract concentration.