Honey bee colonies in South India are being affected by a viral disease first found in Thailand

Thai Sacbrood, a viral disease affecting honey bee colonies, has resurfaced in South India. The disease, which has been dormant in the southern states for some years, is back and impacting the population of bees, especially of the Apis cerana species. This, in turn, can have far-reaching consequences for human life that is indirectly or directly dependant on honey bees.

What’s Thai sacbrood?

Thai sacbrood virus is a variant of sacbrood virus, a viral disease affecting honey bee colonies. Thai sacbrood virus disease was first observed in Thailand in 1976. In 1991-’92, there was an outbreak of the virus in India that resulted in the destruction of more than 90% of the then-existing bee colonies in South India. The disease kills bees when they are larvae, thereby reducing the population of bee colonies.

To identify the diseased combs, the combs are observed for any colour change. The colour of the prepupae (the developmental stage before the pupal stage) changes from white to yellow, then to dark brown. Other symptoms include: the presence of prepupae with raised, pointed heads in the comb cells, and dead larvae that turn into “sac-like” structures filled with fluid. At the age of 10 days, they can be easily removed. Sacbrood virus that attacks Apis mellifera is less virulent when…

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