Assessment of the Inhibitory Impact of Novaluron, A Recent Insect Growth Regulator, on the Reproductive Potential of Spodoptera littoralis (Boisd.)(Lepidoptera: Noctuidae).

Document Type : Original Article

Authors

Department of Zoology and Entomology, Faculty of Science, Al-Azhar University, Cairo, Egypt

Abstract

The Egyptian cotton leafworm Spodoptera littoralis is one of the destructive pests of field crops in the tropical and subtropical areas of the world. The objective of the present study was to assess the impact of Novaluron on the reproductive potential of this pest. A series of concentrations (1.0, 0.1, 0.01, 0.001 & 0.0001ppm) was prepared and applied on the freshly molted penultimate instar larvae. Another series (0.1, 0.01, 0.001 & 0.0001 ppm) was prepared and applied on the newly molted last (6th) instar larvae. The results can be summarized as follows. The tested compound exhibited a predominantly inhibitory effect on the oviposition efficiency, regardless the concentration and time of larval treatment. Both fecundity and fertility had been drastically reduced, in a dose-dependent course, regardless the time of treatment. Irrespective of the concentration and time of treatment, Novaluron halted the embryonic development, since the incubation period of eggs was remarkably prolonged. In light of the present results, Novaluron acts as an antigonadotropic compound in S. littoralis

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