Effectiveness of insecticides in the control of Conotelus sp. (Coleoptera: Nitidulidae) in passionfruit

Abstract

Abstract Conotelus sp. (Coleoptera: Nitidulidae) is a substantial pest of passion fruit production in the Zona da Mata region of Rondônia, Brazil, making this agricultural activity unviable. This study evaluated the toxicity of registered and unregistered chemical insecticides for passion fruit cultivation against Conotelus sp. under laboratory conditions. Eight insecticides were evaluated at recommended field application concentrations. Passion fruit flowers sepals were immersed in insecticide solutions, and five larvae measuring 2 to 3 mm were placed on these sepals. Additionally, LC50 and LC90 values were determined for the insecticides fenpropathrin and chlorpyrifos. The results showed that chlorpyrifos, fenpropathrin, spinetoram, imidacloprid, chlorfenapyr, and thiamethoxam were effective in controlling Conotelus sp. larvae, demonstrating their potential for managing this insect pest. The LC50 values of chlorpyrifos and fenpropathrin for Conotelus sp. were 3.19 g a.i./100 L and 22.09 g a.i./100 L, respectively, showing the higher toxicity of chlorpyrifos. The estimated LC90 values for chlorpyrifos and fenpropathrin are 8.36 g a.i./100 L and 79.04 g a.i./100 L, respectively. These findings strengthen the scientific basis for selection and implementation of management measures to control Conotelus sp. in passion fruit plantations.