Baseline toxicity of ten insecticides from organophosphate, pyrethroid and novel mode of action groups against Droschica mangiferae (Homoptera: Margarodidae) collected from citrus orchard in 2017–19

Drosicha mangiferae (Green) (Homoptera: Margarodidae) is sucking, polyphagous, highly fecund and destructive insect pest of mango, citrus, guava, and plum java. Control of this pest in citrus orchards is dependent upon use of insecticide from several groups which might reduce the efficacy of several chemicals. In this study, we have generated the baseline toxicity data of ten formulated insecticides viz., deltamethrin, bifenthrin, fenpropathrin, methidathion, chlorpyrifos, acetamiprid, imidacloprid, thiamethoxam, spirotetramat, and flonicamid against adult females of D. mangiferae by conducting leaf-dip bioassays in the laboratory, over the period of consecutive three years from 2017–2019 in order to assess the susceptibility status of field collected populations from citrus orchard of Sargodha, Punjab, Pakistan. Results showed that bifenthrin, thiamethoxam, spirotetramat and flonicamid exhibited higher toxicities to D. mangiferae adult females owing to very low LC50 values. Significantly larger LC50 values were obtained for all other insecticides such as deltamethrin, fenpropathrin, methidathion, chlorpyrifos, acetamiprid, and imidacloprid which indicated that these insecticides showed comparatively lower toxicities. It can be concluded that insecticides with very low LC50 values should be incorporated in the management program of D. mangiferae to increase control efficiency and minimize the resistance development.