The erosion of honey bee diversity is laying waste beekeeping in eight districts of the state as the insects are becoming vulnerable to the Thai Sac-Brood virus.
Nagendra Sagar, an expert in apiculture, said for farmers engaged in beekeeping, the joy of the arrival of spring is soon overtaken by dread as bee colonies are reduced to rotting piles of larvae thanks to a viral disease which spreads like wildfire.
The virus, believed to have come from Thailand, has been studied in parts of the state from as far back as 1992.
However, experts feel that as beekeeping turned from a hobby to a thriving business following government aid programmes, the desire to raise more colonies has sidelined natural diversity.
Limited supply within Karnataka and cheaper prices in Kerala and Tamil Nadu mean farmers bring bees of the same colonies.
K T Vijaykumar, heading the All India Coordinated Research Project on Honeybees and Pollinators at University of Agriculture Sciences in Bengaluru, said the disease has ravaged the bee colonies in Uttara Kannada, Dakshina Kannada, Udupi, Hassan, Kodagu, Shivamogga, Chikkamagaluru and even parts of Dharwad.
“We are trying several solutions. However, diversity of honey bees is important to keep the virus at bay. Colonies should be developed locally with best local strains of bees, especially in the Western Ghats and coastal districts, where the disease is ravaging through colonies,” he said.