K. Ananthanarayana ¹, K. P. Salin ¹, Y. Somasekhara Goud ¹, K. Subadra Bai ¹

Affiliations
1 Sugarcane Breeding Institute, Coimbatore - 641007, IN

Abstract

Two parasitoids Amitus minervae Silv. and Encarsia ochai Viggiani were found to occur on the sugarcane whitefly Aleurolobus barodensis Mask. A. minervae occurred naturally at Coimbatore causing maximum parasitization of the whitefly. Its multiplication rate was as high as 90 times. It killed a large proportion ofthe female pupae ofwhitefiy. Two to seven wasps developed from one pupa. It was also seen in Rajapalayam area of Tamil Nadu, Surat District of South Gujar at and Buldana area of Maharashtra. Distinguishing morphological and biological characters, habits and potential of A. minervae in biocontrol are discussed.

Keywords

Amitus minervae,Encarsia ochai, Aleurolobus barodensis.

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S. Easwaramoorthy ¹, H. David ¹, K. Subadra Bai ¹

Affiliations
1 Division of Crop Protection Sugarcane Breeding Institute, Coimbatore - 641 007, IN

Abstract

Toxicity of seven insecticides viz.,carbosulfan, dimethoate, malathion, monocrotophos, cypermethrin, decamethrin and fenvalerate each at three concentrations were tested for their relative toxicity to Adelencyrtus mayurai (Subba Rao), the principal parasitoid of sugarcane scale insect, Melanaspis glomerata (Green), by exposing the adults to the treated surface. At recommended concenrratfori, both fenvalerate (31.3% mortality) and deltamethrin (49.9%) proved to be less toxic to the adult parasitoids. Malathion caused 93.0 % mortality, while the other insecticides inflicted cent per cent mortality. The mortality increased with increase in the concentation of the insecticides and decreased with increase in time lag between treatment with insecticide and exposure of the parasitoid to the treated surface.

Keywords

Adelencyrtus mayurai, Parasitoid, Melanaspis glomerata, Insecticide Susceptibility.

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