Colour-changing butterfly bred at Bannerghatta park

The Bannerghatta Biological Park (BBP) has successfully bred the ‘dark brand bush brown butterfly’ that seasonally changes colour.

Officials and entomologists at the butterfly park in the BBP successfully propagated the species and bred about 400 to 500 of them. Despite failing initially, entomologists achieved a breakthrough six months ago when they documented the butterfly’s lifecycle in a lab condition.

“Breeding this butterfly took us several months,” admitted Vanashree Vipin Singh, Chief Conservator of Forest and BBP Executive Director. “We had no clue about the preferred host plant on which the butterfly lays eggs or what it feeds on. After months of efforts, we multiplied them in the park. The butterfly is unique since it changes its colour according to the seasons. It appears in dark van dyke brown in winter and dons slightly a paler colour in summer, blending into the dry deciduous conditions.”

Lokanath V, an entomologist at the butterfly park, said they caught a butterfly of the species in the forest and observed it in the laboratory. “We found that they lay eggs on the blades of normal grass which many of us tend to ignore,” he said. “Locally, it thrives on the Ragi grass.”

Unlike other butterfly species that feed on flower nectar, the dark brand bush brown feed on rotten fruits such as banana, pineapple, and orange. The entomologists simulated the habitat conditions and initially bred about 50 butterflies. “In the last two months, we bred about 500 of them."

Officials said a single white-centred black eyespot appears correspondingly on the forewings during the wet season. As the weather turns dry, the eyespots fade into minute white specs. The single eyespot on both the wings helps experts distinguish the species, which otherwise appears no different from its family.