The objective of this work was to assess the insecticidal potential of aqueous extracts of four arboreous species: mesquite (Prosopis juliflora), "aroeira" (Myracrodruon urundeuva), leucaena (Leucaena leucocephala) and "sabiá" (Mimosa caesalpiniifolia), under four concentrations, 3, 5, 7 and 10%. Three parameters were evaluated in Bemisia tabaci (Gennadius 1889) (Hemiptera: Aleyrodidae): the presence of secondary compounds, mortality of eggs and nymphs, and alterations in insect's fertility. The presence of tannin was determined in all species, while alkaloids were observed only in P. juliflora and M. urundeuva; saponins were not detected in any species. Only the exctracts of P. juliflora and L. leucocephala caused significant mortality in eggs and nymphs, reaching, in some treatments, 75% mortality. These extracts and the one from M. caesalpiniifolia altered insect's fertility, reducing the reproduction rate, the mean generation time and the intrinsic growth rate for three generations of B. tabaci. The observed effects varied according to the concentration of the extracts tested.
Bemisia tabaci; Anacardiaceae; Leguminosae; tannins; insecticidal plants
