Control químico de la cochinilla roja australiana (Aonidiella aurantii Maskell) con productos sistémicos aplicados al tronco y al suelo en plantaciones jóvenes de limonero

the use of systemic insecticides, such as imidacloprid and thiamethoxam, represents an interesting alternative to control insect pests because of their action mode and the possibility of being applied to soil and trunk, minimizing adverse effects on beneficial insects. both insecticides were recommended to control various citrus pests, such as leafhoppers, psyllids and the leafminer. this study evaluated the efficacy of both insecticides to control california red scale aonidiella aurantii maskell. three field trials (one per year) were performed using two, three and four-year-old lemon plantations, respectively, so as to compare different doses and application methods. mineral oil 1%, conventionally used by citrus growers, was the control treatment. higher doses of imidacloprid 35% applied to soil (0.35 and 0.70 g a.i./cm trunk diameter) controlled a. aurantii throughout the three years of trials. a lower efficacy was recorded for 0.25 g a.i. of imidaclorpid in four-year-old plants. the same was observed in soil applications of thiamethoxam 25% (0.25 g a. i.), which controlled a. aurantii populations in two and three-year-old-plants, but their efficacy was lower in four-year-old plants. trunk applications of imidacloprid 20% (0.20 g a.i.) evaluated only in two-year-old plants controlled the pest.