Battling The Bloodsuckers

Just the kind of bug you want hanging around your ankle
(Globe file photo)

Helicopters are flitting around today over Bellingham, Medfield, and Millis. Why all the annoying buzzing? To reduce the amount of those other buzzing, biting annoyances -- mosquitoes.

The drenching rains earlier this month have spawned a bumper crop of mosquitoes, including aggressive breeds not usually encountered until summer, the director of the Norfolk County Mosquito Control Project said today.

As a result, the Norfolk mosquito control district has expanded its annual springtime spraying, said district director John Smith. Two helicopters took to the air today, dropping pellets containing a widely used pesticide that is favored by mosquito-control specialists because it kills bugs before they reach adulthood. Public health specialists believe the pesticide does not present a significant threat to the environment.

The helicopters this morning targeted Norwood, Canton, and Bellingham, and this afternoon moved to Medfield and Millis. On Wednesday, the helicopters are expected to shift to central Norfolk County and, on Thursday, Dedham, Quincy, and Weymouth.

The springtime treatments are usually restricted to wetlands, but because of the recent soaking rains they have been expanded to the flood plain of the Charles and Neponset rivers, Smith said. The current spraying is largely intended to limit the emergence of nuisance mosquitoes, as opposed to treatments later in the year, which are aimed at limiting the spread of diseases spread by mosquitoes, such as West Nile virus and Eastern equine encephalitis.

Even with about 12,000 acres treated, Smith said he still expects some mosquitoes to escape -- including the more aggressive summer breeds.