Use of Vegetable Oils in the Control of the Citrus Black Fly,Aleurocanthus Woglumi (Hemiptera: Aleyrodidae)

This research aimed to evaluate different vegetable oils in the control of the citrus black fly, Aleurocanthus woglumi. The effect of vegetable oils of soybean (Glycine max), corn (Zea mays), sunflower (Helianthus annuus), cotton (Gossypium hirsutum) and extract of neem (Nim® Rot) was evaluated using four concentrations (0 (control), 0.5, 1.0 and 1.5 mL/L) for each extract, on the fourth-instar nymphs and egg masses of A. woglumi. The leaves containing insects were immersed in a 500 mL-beaker containing vegetable oils in their respective concentrations. Data were analyzed according to a randomized design in a factorial scheme (5 x 4) corresponding to vegetable oil and concentration, respectively, followed by means separation with Tukey's test at 5% probability, using the program ASSISTAT 7.5 beta. It was found that all vegetable oils were effective in causing mortality of the insects. The mortality rate of the fourth nymphal stage was above 90% for all vegetable oils used. For the ovicidal activity, cottonseed oil provided 100% egg mortality, whereas corn oil resulted in lower mortality (48.9%). After treatment with the oils, eggs turned to a dark color. The nymphs that hatched often dried out and were therefore not viable. These results indicate the high efficiency of oil applications on the mortality of the citrus black fly.