August 4, 2006
Flight of the greenheads
By ERIC WILLIAMS
STAFF WRITER
The good news? Only two more weeks or so of greenhead fly season. The bad news? Until then, the insects are determined to stab you with their stilettolike mouths
and lap up a little pool of your blood.
And that smarts.
Greenhead fly boxes stand in the marsh near Pamet River in Truro. Half of the flytraps don't use greenhead bait, an ox-scented solution.
(Staff photo by Paul Blackmore)
''It was like World War III out there on Tuesday night,'' said Scott Penfield, referring to an evening excursion on Nauset Beach in Orleans. He said the night went from beach party to horror show in about 10 minutes.
''We got attacked,'' recalled Penfield, 23, who grew up in Harwich. ''There were 10 to 15 flies on each person, swarming around our heads. You just end up running down the beach, smacking at them left and right, trying to get away.''
You can run, but you can't hide from tabanids, the family of flying bloodsuckers that includes deerflies, horseflies and greenhead flies. Sooner or later, the slash and slurp fly-girls (it's the females that need blood for egg production) will head for your tasty flesh with wild abandon.
''They're used to biting larger mammals that can't swat them,'' said David Simser, entomologist with the Cape Cod Cooperative Extension. ''So, their feeding method is to create a wound.''
And why don't greenheads bug off, even when you're swatting at them like Moe from the Three Stooges?
''They're just not worried about it,'' said Gabrielle Sakolsky, staff entomologist for the Cape Cod Mosquito Control Project. ''They're not smart. They land
on the cars, they smell the emissions
from the car, they go in the cars, they land on anything.''
Sakolsky, the closest thing
The greenhead fly
(Cape Cod Mosquito Control Project)
the Cape has to a greenhead guru, manages 850 greenhead flytraps - those marsh-dwelling blue boxes - from Provincetown to Woods Hole. This has been an average or slightly greater-than-average greenhead year, she said, based on periodic counts of dead flies at some of the boxes. She thinks the greenhead season started a few days earlier this year, though.
Sakolsky said the greenhead season, which peaked around the third week in July, is on the wane, with about two weeks to go. By then, adult greenheads will have laid their eggs and gone to the great fly-strip in the sky.
At the height of the season, a greenhead box trap can capture 800 flies in three hours, said Sakolsky, who appears almost gleeful about her role as the greenhead reaper.
Unfortunately, bug repellent is no match for greenheads, she said.
''They are attracted by smell, but they're also visual, so that's how the boxes work. Half of those boxes don't even have bait'' - an ox-smelling concoction, she said.
Could greenheads be getting smarter, perhaps avoiding the traps?
Simser, the entomologist, floated such a theory yesterday, though he warned he had no data to back it up. ''I think the greenheads that nail you behind the knee are the ones that live to reproduce,'' he said. ''They don't get swatted