Efeito do óleo essencial de cravo Syzygium aromaticum (L.) Merr. & L.M. Perry (myrtaceae) sobre ninfas de Planococcus citri (Risso, 1813) (hemiptera: pseudococcidae)

Abstract

Planococcus citri (Risso, 1813) (Hemiptera: Pseudococcidae) is a cosmopolitan, polyphagous mealybug known for the white, powdery wax it secretes on its body surface. This pest can negatively impact the productivity of a wide variety of crops. The most common control method has been the application of synthetic insecticides, which pose risks to the environment, harm natural enemies, and often show limited effectiveness. As an alternative strategy, the use of essential oils has shown potential. This study aimed to evaluate the contact toxicity of clove essential oil, Syzygium aromaticum (L.) Merr. & L.M.Perry (Myrtaceae), against P. citri nymphs. The essential oil was obtained by steam distillation of leaves and flower buds and purchased from Quinarí®. Different concentrations were tested to estimate lethal doses via Probit analysis. Pumpkin discs (5 cm in diameter) were placed in 8 cm Petri dishes, each infested with ten nymphs of P. citri per replicate. Treatments were applied using a Potter spray tower at 5 psi with a spray volume of 2.3 mL, corresponding to a deposit of 1.9 ± 0.37 mg cm−2. Mortality was assessed after 48 hours. The LC50 and LC90 values were estimated at 11.19 and 41.72 μL.mL−1, respectively. A dose-dependent increase in mortality was observed, with rates of 6.0%, 22.0%, 34.0%, 70.0%, and 96% for the concentrations tested. The results indicate that clove essential oil exhibits promising lethal contact activity against P. citri nymphs.