 Within species colour variaion among butterflies is known as Polymorphism. Many butterfly species have more than one form. They often look to be two different species, but they are not. The polymorphism can be put in to following catagories:
- Sexual Diamorphism
- Seasonal Diamorphism
- Polymorphism
Sexual Diamorphism is found in all the families of butterflies. This is more common to Whites, Yellows and blues and certain other Lycaenidae butterflies. Among blues the males are more vibrant in colour than the females. The Common Emigrant also shows distincive sexual diamorphism. Some palatable species mimic unpalatable poisonous butterflies to avoid predation. Here the two sexes look entirely different. The Common Mormon Female mimics the Crimson Rose; the Danaid Eggfly female mimics the Plain Tiger; the Great Eggfly female mimics the Indian Common Crow.
Seasonal Diamorphism is a phenomenon that shows variation in the colour of butterflies of the same species in different seasons. Species like the Common Emigrant, Evening Brown, Lemon Pansey, Common Fivering and certain other brush footed butterflies exhibits seasonal variation in their colour and pattern on their wings. In India Distinctive seasonal diamorphism occurs during monsoon wet season and post monsoon dry season.
Polymorphism is exibited occassionaly by a few species of butterflies where in they have more than two forms of colouration. The Common Mormon has four forms. A form mimics the Common Rose another mimics the Crimson Rose. |
