Sublethal impact of paraquat on the life span and parasitic behavior of Diaeretiella rapae M’Intosh |
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| Authors: | Rui Xu Peter E Mortimer Rong Ping Kuang Jun He Wu Di Zhang Fang Yin |
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| Institution: | 1. School of Energy and Environmental Science , Yunnan Normal University , Kunming , China;2. World Agroforestry Centre , ICRAF China &3. East Asia Node, Heilongtan , Kunming , China;4. Centre for Mountain Ecosystem Studies , Kunming Institute of Botany , Kunming , China;5. College of Life Science , Yunnan University , Kunming , Yunnan , China;6. College of Economics and Management , Yunnan Agricultural University , Kunming , China |
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| Abstract: | This study focuses on assessing the impact of sublethal doses of paraquat on the survival, the emergence, the life span and the parasitic behavior of Diaeretiella rapae M’Intosh (Hymenoptera: Braconidae). The impact of sublethal doses was measured at room temperature using different densities of the cabbage aphid Brevicoryne brassicae. The results reveal that the field dose of paraquat caused 100% mortality in D. rapae. The percentage emergence of D. rapae decreased from 80.5% in the control group to 71.5% when treated with the lowest concentration of paraquat. Similarly, the life span of parasitoids that emerged from the mummy treated with paraquat also decreased significantly. Oviposition capability and ovipositor thrusting frequency of D. rapae also treated with sublethal dose paraquat decreased significantly along with a shortened patch residence time in the foraging area. |
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| Keywords: | Toxicity functional response herbicide natural predator biological control |
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