Controle populacional de Diaphorina citri Kuwayama (Hemiptera: psyllidae) por aplicações sucessivas de inseticidas químicos e biológicos

Abstract

Huanglongbing (HLB) is considered the most important disease affecting the citrus industry worldwide, and its spread is associated with the Asian citrus psyllid, Diaphorina citri Kuwayama. Due to the absence of resistant commercial cultivars, one of the main strategies for HLB management is the control of its insect vector, which is predominantly achieved through applications of chemical insecticides. However, control failures have been reported in citrus orchards and may be associated with the use of insecticides with a limited ability to interfere with the different deve-lopmental stages of the pest. Therefore, this study aimed to evaluate the efficacy of chemical insecticides with different modes of action and biological insecticides in the management of D. citri following sequential applications. The experiment was condu-cted under controlled conditions at the Sylvio Moreira Citrus Research Center of the Agronomic Institute of Campinas (IAC), using a completely randomized design with 10 treatments and four replicates. The treatments consisted of applications of bi-fenthrin, imidacloprid, malathion, buprofezin, pyriproxyfen, formetanate hydrochlori-de, cyantraniliprole, Cordyceps fumosorosea, Beauveria bassiana, and an untreated control. Control efficacy against the D. citri population was assessed by considering nymphs, adults, and the total insect population. The results demonstrated that cyan-traniliprole, imidacloprid, bifenthrin, and malathion were effective in controlling nym-phs, adults, and the total population. Pyriproxyfen and buprofezin provided interme-diate control of nymphs but showed low efficacy against adults. The biological insecticides exhibited poor performance against all developmental stages evaluated, indi-cating that their use should be directed toward long-term management strategies. It was concluded that bifenthrin, cyantraniliprole, imidacloprid, and malathion were the most effective insecticides for the population control of D. citri, although cases of re-sistance to some of these insecticides have been reported. Insecticide selection should consider all stages of the insect life cycle, and the rotation of modes of action is essential to delay the evolution of resistance, while integration with biological con-trol contributes to the long-term sustainability of pest management.