INSECTICIDAL POTENTIAL OF CITRUS AND MANGO ESSENTIAL OILS AND SELECTED CONSTITUENTS ON SILVERLEAF WHITEFLY

Bemisia tabaci is a cosmopolitan pest responsible for causing harm to crops in the agricultural hub of Petrolina in the state of Pernambuco, Brazil. We investigate the lethal and sublethal effects of vapors from essential oils obtained through hydrostillation of the peels of four species of Citrus and the latex from Mangifera indica (var. "rosa" and "espada") on B. tabaci. The chemical analysis by GC-MS of the oils led to the identification of 71 constituents, with limonene the major component of the Citrus oils and terpinolene the major component of the M. indica oils. B. tabaci was more susceptible to the C. aurantiifolia (LC50 = 0.70 µL L-1 air) and C. limon (LC50 = 1.77 µL L-1 air) oils, which had the same level of toxicity. The Citrus and M. indica oils also led to a reduction in the fecundity of pest. The lethal and sublethal action of the constituents linalool, α-terpineol, α-pinene, β-pinene, terpinolene and limonene is also discussed. The toxicity of the oils investigated herein associated with the reduction in fecundity is a considerable advantage in the management of B. tabaci. However, for practical use of these oils as a novel insecticide to proceed, further research is required to address safety issues for human health and determine the formulation to improve the insecticidal potency, stability and cost-benefit ratio.