Repellent Effect of Herb Extracts on the Population of Wingless Green Peach Aphid, Myzus persicae Sulzer (Hemiptera: Aphididae)

Investigation of the repellent and insecticidal effects of 8 kinds of herb extracts (chives, dokudami, eucalyptus, lavender, peppermint, cherry sage, sweet pepper and tansy) against wingless green peach aphids were conducted in laboratory and field test. In laboratory repellent tests, 20 aphids were placed between a radish leaf and filter paper for 16 h and aphids on radish leaf were calculated. In laboratory insecticide tests, 20 aphids were placed on a radish leaf treated with herb extract, and live aphids were counted after 16 h. In field tests, the number of aphids that propagated on radish leaves treated with each herb extract was assessed every 3 days. In the laboratory, dokudami, tansy and sweet pepper extracts repelled aphids, while chives, sweet pepper and tansy extracts killed them. In particular, sweet pepper and tansy extracts proved to be a potent insecticide against aphids. In the field test, the results found that extracts from dokudami, cherry sage and lavender had repellent effect on aphids. In particular, dokudami extract was a highly effective repellent against aphids. These findings suggest that dokudami extract can be used to control wingless green peach aphids in the field.