Seasonal climatic influence on the leaf biochemicals of Sal (Shorea robusta) flora and in situ breeding behaviour of Laria ecorace of tropical tasar silkworm Antheraea mylitta Drury

The voltinism and breeding behaviour of Laria ecorace was studied in situ in relation to the climatic factors and foliar biochemicals of the Shorea robusta (Sal) leaves. Meteorological data was recorded with higher average temperature during May and June (30.77 0C and 29.81 0C) whereas higher average humidity (%) recorded during rainy season from July to September (82.93, 84.50 and 81.66) and a corresponding higher rain fall (mm) from July to October (195, 255, 185 and 205). Linear correlation between the leaf moisture and biochemical contents with the abiotic factors was studied. It revealed a positive correlation between leaf moisture (Av. temp.0.673; Av. humid 0.246), while, proteins and carbohydrates of leaf have positive correlation with humidity but negatively correlated with maximum temperature (-0.538). On contrary, leaf phenol and tannin showed negative correlation with the abiotic factors. The suitability of leaf nutrition and the ecological factors are prominent for the Laria silkworm breeding and subsequent cocoon production on Sal. A peak moth emergence was observed during second and third week of June at the onset of rainy season with coupling rate of 45% over total emergence. Larval population was found more during August to October. At the same time, higher survivability and cocoon production was recorded.