Evaluation of Infestation of Phyllocnistis citrellaStainton (Lepidoptera: Gracillariidae) and its Parasitism After the Application of Betacyhalothrin and Thiamethoxam on Quadrates of Citrus Treese

摘要

Citrus is the major fruit crop in Pakistan which has now become number one export commodity after mango. A number of insect pests damage this fruit crop, Citrus leaf miner, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is the most important insect pest due to its involvement in citrus canker. Present studies were carried out to evaluate the infestation of citrus leaf miner and its parasitism after the application of betacyhalothrin and thiamethoxam on quadratic sides of citrus trees. For this purpose 8 trees with four directions (south, east, north and west) were selected randomly and tagged. Infestation and parasitism was counted on spring and monsoon flush on every four sides of the tagged citrus trees. Each insecticide was applied to three trees in three replications. After 1 application, 2 application st nd was done only when fresh leaf miner attack appears on selected plants. The pest’s population and parasitism was recorded in citrus research area at Post-Graduate Agriculture Research Station (PARS), Faisalabad. Larval mortality data was analyzed statistically by means of M.Stat. Both chemicals gave significant result against Phyllocnistis citrella Stainton but the best result was given by the Betacyhalothrin 2.5% EC rather than Thiamethoxam 25% WG. In orchard, highest larval mortality(54.20%) was recorded on north side in spring season while lowest larval mortality(44.90%) was recorded in Autumn season on east side. Parasitism was significantly highest in spring season and north side (17.17%) and lowest (11.19%) in autumn season and west side of trees in the orchards.