Evaluation of different insecticides against the citrus leafminer (Phyllocnistis citrella Stainton) (Lepidoptera: Gracillaridae) on citrus seedlings in Sudan

The citrus leafminer (Phyllocnistis citrella), has become an important pest in orchards and nurseries of citrus fruits throughout the Sudan. Hence, various insecticides were screened in this study against P. citrella infesting lemon and grafted grapefruit seedlings in Khartoum State. The experiments were conducted in nurseries during 2011 and 2012. The evaluated chemicals were: foliar sprays of Tracer 480 SC (spinosad), Karate 5% EC (lambda cyhalothrin) and Nembicedine 0.03% EC (azadirachtin) as well as soil drench of Actara 25 WG (thiamethoxam) and Confidor 200 SL (imidacloprid). All the studied insecticides were effective in reducing leafminers infestation at variable levels compared with the untreated control. Regarding foliar sprays, Tracer 480 SC proved the best significant results on lemon seedlings for two weeks, followed by Karate 5% EC and Nembicedine 0.03% EC. Lemon and grafted grapefruit seedlings treated with Actara 25 WG and Confidor 200 SL were almost free from miners attack for more than a month, indicating the superiority of these two soil applied chemicals over those sprayed. Thus, both insecticides can be used for citrus seedlings. However, the performance of such chemicals on orchard trees of different citrus species should be evaluated before concluding on their wide scale usage.