Repellence property of traditional plant leaf extracts against Aphis gossypii Glover and Phenacoccus solenopsis Tinsley

Abstract

Aphid, Aphis gossypii Glover (Hemiptera: Aphididae) and mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) are major polyphagous pests in Vadodara agricultural fields. To control these sap sucking insect pests; farmers are using broad spectrum insecticides which are toxic to non target insects. Therefore, the objective of this study is to control these pests by using biorational control methods. Hence, laboratory assays were carried out to evaluate the repellent property of leaf extracts of three indigenous native botanicals namely; Azadirachta indica A. Juss; Eucalyptus globules L. and Ocimum basilicum L. against aphids and mealybugs. The methanol extract of leaf was isolated by using soxhlet method. The leaf extracts were applied against aphids and mealybugs at dose levels of 1, 2, 4, 8 and 10%. Observations were made at 12 and 24 h. After 24 h of release of aphids and mealybugs, the highest repellency was recorded in A. indica leaf extract which gives 99.0 and 97.0% followed by E. globules leaf extract giving 96.0 and 93.0%. While minimum repulsion was seen in O. basilicum leaf extract 91.0 and 88.0%, respectively. As the dose increases, the repellent effect also increased irrespective of the plant extracts. The use of such plant extracts can control the population of serious pests like aphids and mealybugs in an environmental friendly way. Key words: Aphid, mealybug, biorational control, botanicals, Azadirachta indica, Eucalyptus globules, Ocimum basilicum.