Evaluation of selected insecticides against brinjal sucking insect pests and their effect on natural enemies / Aina Atirah Sanusi

Brinjal is one of the most widely cultivated in the world and able to produce high yields even though under hot-wet environment. However, the production of brinjal becomes low because of some sucking insect pests. The major sucking insect pests on brinjal are thrips {Thrips palmi), whitefly (Bemisia tabaci) and aphid {Aphis gossypii). The applications of insecticides are important in controlling of brinjal pests but it also causes adversely effects on the natural enemies of pests. Therefore, this study was carried out to examine the effect of selected insecticides on brinjal sucking insect pests, natural enemies and the changes in the interactions between pests and natural enemies after application of these insecticides in brinjal ecosystems. The studies were conducted at "share farm" UiTM Melaka, Campus Jasin in an open field condition for two cropping periods. The selected insecticides consist of neonicotinoid groups include imidacloprid, acetamiprid, dinotefuran and cyantraniliprole. Among the treatments being tested for their effectiveness in suppressing sucking insect pests, it was observed that acetamiprid gave the best control for thrips and imidacloprid gave the best control for whitefly and aphids. For natural enemies (spider), imidacloprid and cyantraniliprole were classified as moderately harmful while acetamiprid and dinotefuran were classified as harmless or slightly harmful. The results also showed that there was an interaction between spider with thrips and aphids but no interaction between spider with whitefly after treatments application. The significance of this study would give a great deal of contributions to farmers in terms of choosing the most effective insecticides on pests whilst at the same time safer on natural enemies.