Field Evaluation of Selected Botanical and Synthetic Insecticides against Mealybug Drosicha mangiferae Green (Hemiptera: Pseudococcidae) Infesting Citrus Orchards in Pakistan

Mealybug Drosicha mangiferae Green (Pseudococcidae: Hemiptera) is a destructive sap-feeding pest of a number of horticultural and agricultural crops in Indo-Pak region. It has been an emerging threat to citrus industry in Pakistan and is considered as hard-to-control pest. This study evaluated some selected pest control options against the infestation of D. mangiferae under field conditions. The treatments included some most effective conventional and novel chemistry insecticides, botanicals and cultural control practice (i.e. two under-canopy deep hoeings with 15 days interval along with lower-branch pruning) alone or in combination with the entomopathogenic fungus Beauveria bassiana (@1x108 conidia mL-1). First experiment was conducted in March 2016 and 2^nd was performed from November 2016 to March 2017 in a citrus (Citrus reticulata cv. kinnow mandarin) orchard. In first year field experiment, there was a significant impact of all treatments on the reduction of mealybug infestation (F_{9, 39} = 39.10, P < 0.001; HSD at α = 0.05) as compared to control plants. Results of 2^nd experiment also clearly demonstrated a significant impact of different treatments on the mealybug infestation (F_{12, 103} = 58.75, P < 0.001; HSD at α = 0.05) as compared to control. At both 3 and 7 days post-treatment, maximum reduction of mealybug infestation was recorded in plots treated with spirotetramat (87.75±3.91%) and lambda-cyhalothrin (85.52±4.42%) in combination with EPF followed by these two insecticides and sulfoxaflor alone. Based on overall study results, the insecticidal formulations of spirotetramat, lambda-cyhalothrin and sulfoxaflor in combination with EPF and under-canopy hoeing are recommended to the local citrus growers for an effective control of D. mangiferae infestation.