Effects of bio-pesticides on Eretmocerus warrae (Hym., Aphelinidae), a parasitoid of Bemisia tabaci (Hom., Aleyrodidae) |
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Authors: | P Kumar M Whitten G Thoeming C Borgemeister & H-M Poehling |
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Institution: | Department of Entomology and Agricultural Zoology, Rajendra Agriculture University, Pusa, Samastipur, India; Department of Integrative Biology, University of Queensland, Qld, Brisbane, Australia; Department of Ecological Plant Protection, University of Kassel, Witzenhausen, Germany; ICIPE, Nairobi, Kenya; Institute of Plant Protection and Plant Diseases, Leibniz Universität Hannover, Hannover, Germany |
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Abstract: | The sweet potato whitefly Bemisia tabaci (WF) can be controlled by two commercial neem products, NeemAzal-T/S® (1% azadirachtin) for foliar application, and NeemAzal-U (17% azadirachtin) for soil application, alongwith two biorational products of microbial origin, Abamectin (avermectin) and Success® (spinosad). Side effects of these products were tested in a laboratory bioassay against a native aphelinid, Eretmocerus warrae (EW). Eggs and early larval instars of the parasitoid, commonly found outside the host body, were highly susceptible to foliar spray of neem with only 8%, 18% and 55% emergences of adults from treated eggs. larval and pupal stages respectively at recommended dose-rates of 5 ml/l and 1%, 8% and 40% at twice recommend dose-rate (10 ml/l). Soil application with NeemAzal-U marginally affected EW. At highest tested dose-rate of 3.0 g/l, 46%, 64% and 81% emergence was recorded after treatement of plants harbouring WF parasitized by egg, larval and pupal stages of EW respectively. In contrast to neem application, Success® and Abamectin caused high mortality in development stages of the parasitoids. In particular, abamectin was highly toxic to the parasitoids with less than 1% emergence from either of the three development stages if treated with 1–2 ml/l. |
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Keywords: | Bemisia tabaci Eretmocerus warrae avermectin azadirachtin spinosad Thailand |
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