Studies on non-specific α-esterases in two major ecoraces of tropical tasar silkworm Antheraea mylitta Drury

Abstract

Tropical tasar silkworm Antheraea mylitta exhibits diversity in the phenotypic, physio-genetic, behavioural and commercial characters due to diverse habitats. The variability in four populations belonging to two major ecoraces of A. mylitta viz., Daba and Laria was analysed by quantitative assay and electrophoretic profile of non-specific α-esterases in haemolymph samples, also thermo-stable esterases were explored in these populations. An apparent variability was recorded, indicating high heterogeneity with respect to the food plant, region and sex. Higher esterase activity was found in Laria female (4.96±0.63 µmole min-1g-1) and lowest activity (2.68±0.43 µmole min-1g-1) was recorded in the male Daba. Comparative analysis of α-esterase in two populations, showed a variation in number of bands and in the staining intensity. The three esterase bands with Rf values 0.18, 0.44 & 0.49 were prominently appeared when the gels were incubated at 35 °C followed by staining. This appears to be the heat tolerant esterase.