Laboratory evaluation of some insecticides against citrus mealybug Planococcus citri, (Homoptera: Pseudococcidae)

Abstract

Citrus mealybug, Planococcus citri (Risso) (Homoptera: Pseudococcidae), is a serious pest of citrus plants in Pakistan which cause considerable loss to citrus crop both in terms of quantity and quality. The present study was conducted to evaluate the toxic effect of different insecticides at different concentrations against P. citri. Leaf-dip bioassays were performed to assess the toxicity of a pyrethroid (Cypermethrin), an organophosphate plus pyrethroid (Polytrin-C), a neonicotinoid (Imidacloprid) and a synthetic IGR (Buprofezin), using 3rd instar female individuals of P. citri. Data regarding mortality of insects was recorded at 6, 12, 24 and 36 hrs post-treatment (HAT). Maximum mortality was observed in case of Polytrin-C (74.84%) followed by Buprofezin (65.15%) at 36 HAT, while Imidacloprid and cypermethrin were least effective. In case of different concentrations of each chemical, mean maximum mortality was observed at 4 ppm (67.61%) after 36 HAT. Study results suggest that Polytrin-C and Buprofezin are effective chemicals at 4 ppm against citrus mealybug. However, non-target effects of Polytrin-C, such as on biological control agents and other organisms should be determined.