DOUBTS HAVE been raised over the bee safety of a new insecticide awaiting approval for horticultural crops in the UK, following recent research findings.

The Canadian study suggests adult bumble bees exposed to the pesticide spinosad during larval development – at levels they could encounter in the environment – have impaired foraging ability.

But manufacturer’s Dow AgroScience says commercial use of the product since it was first registered in 1997 has provided no evidence of any problems.

“If it affected bee colonies in use we would have got some comeback quite quickly,” said the firm’s Robert Dutton.

While colonies exposed to spinosad in pollen showed only minimal colony effects, bees fed during larval development were slower foragers, according to researcher Lora Morandin.

This means bees take longer to access complex flowers, which could result in weaker colonies and lower crop pollination, she said.

“Adult bees exposed to a pesticide during larval development may display symptoms of poisoning that are not detected by current tests required by regulatory agencies.”

Dr Dutton admitted most testing of spinosad has only used adult foraging bees, but questions whether the study used dry deposits. “In practice once the deposit dries, bees don’t pick it up and it becomes safe.”

Dow is hoping for approval to be granted for spinosad to control caterpillars on brassicas and thrips in onions and leeks during 2005.