Subscribe Now

Every July, the abhorred greenhead flies descend upon the beaches of the North Shore, particularly Crane Beach and Newbury Beach. Located closest to salt marches, these beaches bear the brunt of these pests’ activity, as the flies emerge hungry from laying their eggs in the marshes.

Greenhead flies, commonly known around here as greenheads, are a type of large horsefly, about half an inch in length, and befitted with nasty scissor-like mandibles allowing them easy access to human (and other mammal) blood. 

The flies start developing after the high tide of June, says Plum Island resident Bob Connors. They take about a week to mature, and then live for another couple weeks. “This year, whether it was the rain or the heat, they were really insignificant from the ocean side of the island,” says Connors. “We’ve had a hotter than normal summer, and probably drier than normal.”

Greenheads are active on North Shore beaches, particularly Crane Beach, from around mid-July to early August. They tend to ebb after August’s first full moon high tide.

“This hasn’t been a terrible year. I would call it a very mild year for greenheads,” says Gary Litchfield, another Plum Island resident who can remember certain years being so bad with greenheads that he could hardly venture down towards the bird sanctuary end of the island without getting pelted by greenhead attacks.

He knows many folks who use Avon’s Skin So Soft bug repellent and “swear it works like a charm.” Other will say there’s not much you can do to fully prevent greenhead bites, though we’ve listed some tips below.

You can find Skin So Soft at the beach store on Crane Beach. The Trustees have also mentioned on Crane Beach’s Twitter account that the greenheads have been less than terrible this year.

To avoid greenhead bites, make sure you dry off after going in the water, and avoid spraying perfume, which is said to attract the flies. They’re also said to be attracted to sunblocks and tanning lotions, especially scented kinds. Cover up with pants and sleeves when you can, and try to head to the beach on windier days when the flies are less active.