Aqueous extracts of Leucaena leucocephala and Sterculia foetida to the control of Bemisia tabaci biotype B (Hemiptera: Aleyrodidae)

Abstract

The present research was carried out in Recife-PE, aimed at to evaluating insecticide, insectistatic and repellant effects of aqueous extracts of Leucaena leucocephala (Lam.) De Wit. and Sterculia foetida L. on eggs, nymphs and adults of Bemisia tabaci biotype B (Genn., 1889) on Brassica oleracea var. acephala L. culture. Seeds and leaves of L. leucocephala and S. foetida were collected, dried and ground. Solutions from the aqueous extracts were prepared with 5g of dried vegetable and 50ml of pure water. Leaves of B. oleracea var. acephala were sunk in the solutions for 30 seconds before confining insects on them. Extracts of L. leucocephala seeds and S. foetida leaves caused mortality of 60% and 41%, respectively, on eggs of B. tabaci. Leaves of S. foetida caused the highest effects on nymphal instars, with mortality of 74.6%. None of the tested extract showed suppression on insect oviposition. The treatments of L. leucocephala showed a shorter longevity and higher oviposition than the treatments of S. foetida and the control. The aqueous extracts from L. leucocephala seeds and S. foetida leaves can be a good alternative to the control of B. tabaci.