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Repellent effect of azadirachtin and essential oils on Aphis gossypii Glover (Hemiptera: Aphididae) in cotton plants

The repellence of botanical insecticides has emerged as a promising technique in the alternative control of urban and agricultural pests, being seen as one component of integrated pest management. The aim of this work was to identify the repellence of botanical insecticides on apterous females of Aphis gossypii Glover. Random-choice tests were carried out with discs from the leaves of cotton plants immersed in insecticide solution and in a control (distilled water with 2% DMSO). Azadirachtin was used (0.075%) and the essential oils of Piper hispidinervum CDC, P. aduncum L., Cymbopogon winterianus (L.), C. citratus (DC) Stapf, Foeniculum vulgare Mill, Syzygium aromaticum (L.) Merrill and Perry, Cinnamomum zeylanicum Blume, Schinus terebinthifolius Raddi and Chenopodium ambrosioides L. at a concentration of 0.05%. C. citratus, C. winterianus, P. aduncum, S. terebinthifolius, azadirachtin and C. zeylanicum showed the highest percentage of repellence, 100, 84, 66.67, 64, 60.87 and 48% respectively, and reduced nymph production by 100, 92, 42.9, 87.5, 80.65 and 89, 74%, with significant results from the χ2 test at 10% probability. In tests with F. vulgare (χ2 = 3.66, P = 0.05) females of A. gossypii were significantly attracted to the treated discs, and there was an increase in the production of nymphs in the results obtained for F. vulgare (χ2 = 5.87, P = 0.02) and C. ambrosioides (χ2 = 14.31, P = 0.001).

Gossypium hirsutum; Cotton aphid; Behaviour; Insecticides of plant origin


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