STUDIES ON MORPHOLOGICAL CHARACTER AND POLYPHENISM OF MELANITIS LEDA (SATYRINAE: NYMPHALIDAE) IN BRAHMAPUTRA VALLEY OF ASSAM, INDIADinata Roy, Subadas Singh, Sanjay Talukdar, Borsha Tamuly and Saikat Maji
A polyphenic trait is a trait for which multiple, discrete phenotypes can arise from a single genotype as a result of differing environmental conditions, which is therefore a special case of phenotypic plasticity happened in nature. Polyphenism is a natural phenomenon which supports living organisms to increase the survivability due to camouflaged. Among Satyrinae butterfly, Melanitis leda is a good example which shows this phenomenon. Also this butterfly is considered as a pest of rice in India. It is also pest of important poaceae crops such as maize. However, butterflies are widely known for its beneficial to nature as pollinators and also as bio-indicators due to their climatic sensitivity. M. leda mainly have two different morph i.e., wet season morph and dry season morph. The dry season form of M. leda is considered to be more variable than the wet season form. Dry Season Forms (DSFs) were identified and collected from Galia forest reserve in Barpeta district of Assam for further studies. The presence of distinctive eyespots was found in DSF1 and DSF2. DSF1, DSF2 and DSF3 was found to have positive and significant correlation with temperature and humidity. Whereas, DSF7, DSF9 and DSF10 had significant negative correlation with climatic parameters within the population. Polyphenism was found to be internally controlled by varied protein concentration with higher protein concentration for DSF1, DSF2 and DSF3 i.e. in morphs formed in high temperature and high humidity condition within the overall DSF population.