Reproductive potential of the parasitic wasp Microplitis rufiventris Kok. (Hym.: Braconidae), reared in hosts treated with chitin synthesis inhibitors

Authors

  • W. E. Khafagi,

    1. Plant Protection Research Institute, Sahahia, Alexandria; Department of Entomology, Faculty of Agriculture, Alexandria University, Alexandria,
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  • E. M. Hegazi

    1. Plant Protection Research Institute, Sahahia, Alexandria; Department of Entomology, Faculty of Agriculture, Alexandria University, Alexandria,
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Prof. Dr. E. M.Hegazi, Alexandria University, Fac. of Agriculture, Dep. of Econ. Entomol., El-Shatby, Alexandria, EGYPT.

Abstract

Different developmental stages of Microplitis rufiventris Kok. larvae were each exposed to a sublethal dosage (0.4 ppm) of Lefenuron [N-{2,5-dichloro-4-(1,1,2,3,3,3-hexafluoropropoxy)-phenylaminocarbonyl}-2, 6-difluorobenzamide] or Lefenuron/Deltanet [O-n-butylO-(2.2-dimethyl-2, 3-dihydrobenzofuran-7-y1)-N, N’-dimethyl-N-N’-thiodicarbamate] by feeding treated artificial diets to parasitized Spodoptera littoralis (Boisd.) larvae to evaluate their effects on the reproductive potential of resulting parasitoids. Lefenuron treatments caused a great reduction in the reproductive ability of either the host insect or its parasitoid. Ovaries of parasitoid females (1 day old) emerged from Lefenuron/Deltanet treatments contained more ova than those from either Lefenuron or controls. Experienced females from Lefenuron/Deltanet treatments deposited significantly more eggs and contained at death more remaining mature oocytes in their calyx and egg-reservoirs. The combination of carbamate insecticide (Deltanet) and chitin-inhibiting growth regulator (Lefenuron) may enhance the reproductive ability of insect parasitoid and may provide a potential means for developing more effective biological control methods against insect pests.

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