The varroa mite attacks bees by introducing a paralysing virus

The Kent Beekeepers Association said the varroa mite had become immune to certain pesticides.

Peter Hutton, spokesman for the group, said: "Unless products are brought in which are effective, the impact on hives in Kent will be devastating."

The government said it was committed to protecting the health of the English honey bee population.

'Paralysing virus'

In a statement, the Department for Environment, Food and Rural Affairs (Defra) said mite resistance to certain varroacides had become a problem.

"Bee-keepers need to adapt the control measures applied when resistance is discovered and use authorised treatments in conjunction with other controls during the year."

Mr Hutton said the mites work by sucking the blood of the adult bees.

"They introduce a paralysis virus which kills the adult bees within five to eight days.

"If there's only a few mites in the colony the number of bees that are going to be killed are very few.

"But when the colony reduces from 90,000 in July to 12,000 for the winter period and there's 2,000 varroa mites the results can be very serious."