Though they don’t sting or transmit disease, the insects are an integral part of our food chain
It’s easy to anthropomorphise butterflies as the eternally well-dressed ladies of nature. Just as it is to call the human party hopper (or in media parlance, a Page 3 regular), a ‘social butterfly.’ But the butterfly has a role that spans well beyond linguistic gymnastics.
Though it neither stings nor transmits disease, the butterfly is a key part of our ecology. “They are an important part of our food web and are good pollinators,” says Dr. Daisy Caroline Mary, Assistant Professor, Department of Environmental Science at Bishop Heber College in Tiruchi.
The 27-acre college campus in the Puthur area is a hotspot of sorts for butterflies right now, as the migration season for these ‘flying flowers’ peaks in October and November.
An insect that mainly flies during the day, the butterfly belongs to the order Lepidoptera. Its plainer cousin, the moth, is included in the same order.
General awareness on butterflies here is low, feels Dr. Daisy, and suggests that more youngsters from local educational institutions and rural areas should be briefed on the life cycle and importance of these insects.
“A study of the diversity of butterflies has not yet been done in Tiruchi,” she says. “But our campus alone has 78 species of butterflies, which means there should be more than that number outside.” Scientists estimate there to be between 12-15,000 species of butterflies in the world.
In 2010, Dr. Daisy published Butterflies of Bishop Heber College, a guide to the insects within the campus, illustrated with photographs taken by her. “The involvement of my husband (Dr. A.Relton, Reader and Head, Department of Social Work at Bishop Heber College) and son (R.Carlton) and a team of my young nieces and nephews enabled me to bring out the pictorial guide,” she says.
Besides this, Dr. Daisy has also published conference papers on the insects.
The colourful wings on butterflies are made of very thin layers of a hardened protein called chitin (human hair and nails are made of this as well). Thousands of minute scales on the chitin layers serve a variety of purposes, including fitting out the butterfly with multi-hued wings.
The scales are also used to soak up the solar heat required to keep the cold-blooded butterfly flying.
The ability of butterflies to fly over long distances is well-known. The most commonly documented of these yearly journeys is that of the Monarch butterfly, which traverses 4,000-4,800 km from Mexico to northern United States and southern Canada.
Butterflies are able to navigate using polarised light (close to the ultraviolet spectrum), which enables them to stay on course even during cloudy days.
In southern India, mass migrations are usually observed during the monsoons.
Many countries have capitalised on the popularity of these insects by setting up dedicated conservatories as part of their zoos.
In Tamil Nadu, the Forest Department is currently constructing a butterfly park in Srirangam, in a bid to make it a tourist attraction.
Such initiatives are commendable, as besides providing relief from a mechanical life, “it would sensitise people about the need to protect nature,” says Dr. Daisy.
For those who’d prefer to watch butterflies at their own pace, she recommends any garden as a useful starting point.
Besides this, butterfly watchers in Tiruchi could also try spots along River Cauvery and Pachamalai, preferably in the forenoon and early evening.
“The larvae of butterflies feed on a variety of plants – each species on a few specific plants,”says Dr. Daisy.
Common host plants are curry leaves, citrus, Calotropis gigantea and so on.
Adults feed on nectar.
Butterflies defend themselves against predators in interesting ways. They are able to isolate toxic chemicals in plants and use them as their own weapons to avoid getting eaten up by larger animals. Usually, the brighter the colours on a butterfly, the more unpalatable it is.
The butterfly is also a skilful make-up artist, and can blend into the background with colour schemes that mimic the surroundings. It can also ‘freeze up’ to look like a twig and escape detection.
To encourage the butterfly’s survival in an urban landscape, Dr. Daisy recommends planting host and nectar plants and avoiding chemical pesticides and fertilisers.