• The Korean Journal of Pesticide Science
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• v.15 no.2
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• pp.194-200
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• 2011

Diamondback moth (DBM, Plutella xylostella L.) is known as the most destructive pest of cruciferous crops worldwide. As most insecticides targeted to mainly larval stage, new insecticides which have hatching-inhibitory or ovicidal activity could be more efficient to control DBM. Therefore, we developed an easy and efficient method for screening ovicidal activity of DBM eggs using aluminum foil. The aluminum foil ($4{\times}12$ cm) coated with filtered juice of chinese cabbage leave (hereinafter called oviposition foil) exposed to 300 newly-emerged adults for 24 hours inside the rearing container. The oviposition foils were replaced every 4 days consecutively after mating, but it was better to discarded over then. Oviposition foil were divided into 6 to 12 pieces depending on egg mass volume. After dipping into test solutions for 10 seconds using faucet, oviposition foil pieces were placed into common petri dish, and then investigated hatchability. The effect of methanol solvent (50%) for 10 seconds dipping on the toxicity against DBM eggs was negligible. In addition, whether covering the petri dish or not should be dependent on nature of active compounds tested. With applying the new bioassay method, methanol extracts from 50 plants were tested the ovicidal activity to DBM eggs. Among them, four plant extracts; Angelica tenuissima root, Lycium chinense root, Cnidium officinale root and Polygala tenuifolia root, showed high ovicidal activity of over 90% control efficacy, against DBM eggs.