Evaluation of Ovicidal Effect of Extracts from Hop, Oregano, Lemon Balm and Clove on the Sunn Pest, Eurygaster maura L. (Hemiptera: Scutelleridae)

Abstract

Botanical insecticides may be an alternative to minimize or replace the use of synthetic chemical insecticides against pests of agricultural importance. In this search, the ovicidal effects of four plant extracts Lemon Balm Melissa officinalis L, Hop Humulus lupulus L, Oregano  Origanum vulgare L. and clove Syzygium aromaticum (L.) were tested against Eurygaster maura L. (Hemiptera:Scutelleridae)  under laboratory conditions. One to three-day-old eggs were dipped in plant extracts. The effects of three concentrations of plant extracts 2.5, 5 and 10% were studied. It was observed that as the concentration increased, the inhibition of egg hatchability increased. Lemon Balm extract didn't show significant ovicidal effect. On the other hand, Oregano and clove extracts moderately showed ovicidal effect. Hop extract revealed the best result in inhibiting egg hatchability (57.49%) at 10% concentration. It can be concluded that hop extract may be used as supportive in an integrated pest management programme aimed at controlling E.maura.