Stage-specific Life Table Parameters of Coccinella septempunctata Linnaeus and Coccinella undecimpunctata Linnaeus (Coleoptera: Coccinellidae) on Different Host Species under Laboratory Conditions

Document Type : Original Article

Author

Plant protection department, faculuty of agriculture, Damanhour University

Abstract

         The ladybird beetles (adults and larvae) are important predatory insects in most crops. They are voracious predators of aphids, scale insects, psyllids, jassids, thrips and whiteflies. The life table studies often use to describe the mortality rates, mortality survivor ratio and the further life expectation for successive age intervals. In this work the stage-specific life table parameters of Coccinella septempunctata Linnaeus and Coccinella undecimpunctata Linnaeus (Coleoptera: Coccinellidae) at four different hosts viz., Myzus persicae, Aphis gossypii, Rhopalosiphum padi and Thrips tabaci was constructed under the laboratory conditions. The developmental stages of C. septempunctata and C. undecimpunctata exhibited the highest apparent mortality, real mortality, mortality survivor ratio and total generation mortality (K value) in case of rearing on T. tabaci compared to those reared on R. padi, M. persicae and A. gossypii. On the other hand, the developmental stages of the two predators showed the highest survival ratio on A. gossypii compared to other preys. Larval mortality was greater in 1st instar than all other instars on the different hosts. The result further revealed that the minimum duration periods of the total larval development of C. septempunctata and C. undecimpunctata larvae were observed when the larvae fed with A. gossypii followed by M. persicae, R. padi and finally T. tabaci. The data on life table parameters indicated that among four different hosts the cotton aphids, A. gossypii has been proved as a most preferable and suitable prey for the development of C. septempunctata and C. undecimpunctata.

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