Butterflies reflect health of ecosystem

Butterflies are the potential umbrella group for biodiversity conservation. They are good subjects for dispersal studies and have enormous ecological importance.

India harbours butterflies of Ethiopian and Oriental sub regions of the world. Butterflies are suitable subjects for the study of community response to disturbance, and they may also be used as environmental bio-indicators. They serve as food for predators at various levels. The larvae, which feed on foliage, are primary herbivores in the ecosystem and are important in the transfer of energy fixed by plants, making them available to the other organisms in the ecosystem.

After bees, butterflies are the second category of insects which are very specific to their food plants. Some plants are shared by a number of butterflies as food. The faunistic survey of butterflies, their occurrence and characteristics provide crucial information on the ecology of a particular region. Based on the flora of an area, one can easily predict the existing butterfly fauna of that region. The presence of grass butterflies indicates complete conversion of forests into an agricultural ecosystem.

Like birds, butterflies also migrate. Generally, migration occurs for want of food, mate and shelter. Nature of vegetation and climatic factors like temperature, wind, moisture and humidity play an important role in their distribution, feeding and reproductive behaviour. In addition, a butterfly population also regulates their natural enemies (parasitoids, pathogens and predators). The number of butterfly species in the world is 17,200. In India, 1,500 species of butterflies have been recorded.

There has been an alarming rise in industrial and automobile pollution in Indian metropolitan cities. In spite of the fast growth, Indian cities still have diverse serene habitats such as several small and large parks and gardens. The country still has forest areas with mixed deciduous and non-deciduous trees, shrubs, scrubs, bamboos, wild and ornamental flowering plants, streams and marshes, serving as ideal habitats for various types of insects, especially butterflies.

They play a major role in pollination of various flowering plants in the country besides a major component of food chain.

India is a vast country with a rich diversity of biotic resources and is ranked one of the 12-mega diversity countries in the tropics. Due to unscientific management of natural resources, much of our native butterflies are fast disappearing. Owing to various reasons such as habitat destruction for ‘development’ (homes and other infrastructure), fire, grazing and scarcity of both larval and adult food plants, butterfly populations may be severely affected in near future.

In addition to these, a variety of threats from human recreational activities, trampling, run-off from roads, litter deposition and weeds are common factors which affect butterfly populations. Weeds displace plants butterflies feed on. A number of butterfly species may already be extinct as a result of habitat destruction during the past several years in India and about 350 Indian butterfly species are included in the red data book.

By regulating humidity and temperature, it is possible to manipulate local population of butterflies. Establishment of butterfly gardens helps to maximise butterfly diversity and its abundance in urban and suburban areas. By careful protection of larval host and adult nectar plants and restoration of habitats, a diverse assemblage of butterflies could be sustained. Alternative host plants should be maintained.

Periodic survey to evaluate the status of butterflies, demography and predator parasite relationship have to be taken up for conservation of butterflies. The control of fire and grazing in green landscapes may be the best step to enhance or maintain butterfly diversity.