Efficacy of a single root drench application of thiamethoxam for the management of dubas bug and white date scale on date palms

Date palms (Phoenix dactylifera) are a vital crop in the Middle East, particularly in Iraq, where infestations by the dubas bug (Ommatissus lybicus) and the white date scale (Parlatoria blanchardi) significantly threaten yield and fruit quality. This study assessed the efficacy of a single soil drench application of thiamethoxam (Actara 240 SC) for controlling these pests in two cultivars, Barhi and Brem, under field conditions. Treatments resulted in a substantial and sustained reduction in pest populations compared to untreated controls over a 120-day period. Residue analysis using gas chromatography demonstrated systemic absorption and gradual dissipation of thiamethoxam in leaves and fruits, with residues declining below detection limits by 120 days after treatment. The temporal correlation between residue decline and pest suppression underscores the prolonged protective effect of root drenching. These findings support the use of a single root drench as an effective, long-lasting, and potentially more sustainable pest management strategy that reduces the need for repeated foliar applications, thereby lowering labor and chemical inputs.