Effect of Deltamethrin on the Leaf Miner (Liriomyza cicerina) of Chickpea and its Parasitoids

Abstract

The objective of this work was to investigate the effects of chemical treatments on larvae and adults of the chickpea leaf miner (Liriomyza cicerina) and its parasitoids. The study was conducted according to the split-plot design with three replicates, during the cropping seasons 2016 and 2017 in the northwestern Tunisia. Deltamethrin treatments were applied on winter and spring chickpea varieties (Nour and Amdoun, respectively) when the pest density reached a level of 2-3 larvae/leaf in 50% of plants in the field. The number of emerged parasitoids and pest adults were recorded, and parasitism rates were investigated after treatments. Results revealed that the number of captured pest adults has been reduced in treated plots compared to control ones. Respective reduction rates attained 64.15% and 60.17% for Nour and Amdoun varieties during 2017. Additionally, the highest and the lowest parasitism rates were recorded respectively for Opius monilicornis 26.09% on control samples and for Diaulinopsis arenaria 2.88% on treated samples of Nour variety. In all experiments, L. cicerina larvae adults and parasitoids mortalities were higher for the spring variety. Hence, the use of more selective insecticides should be recommended to reduce the negative side-effects on the chickpea leafminer natural enemies.