The greenhead fly’s mouth has scissor-like mandibles that can tear into your exposed flesh, while a salivary pump injects a burning anti-coagulant to keep the blood flowing.
Spongy mouthparts soak up the blood meal then the greenhead darts off before you can swat it. and even if you did get a whack at it, you would need a 5-pound hammer to kill it, the old saying goes.
This description of the greenhead fly’s bite was given during the Gloucester Board of Health’s remote meeting last Thursday during which members decided to do something to lessen the chances of residents, boaters, beachgoers and golfers getting bitten and suffering the resulting welts.
The board voted to back a plan to ask the Verga administration and City Council to re-enter the North Shore Greenhead Fly Program and approve funding to install 20 box traps in the salt marsh around Wingaersheek Beach this summer.
The cost to deploy 20 boxes in the area of Wingaersheek Beach would be $4,140 for this season, according to Barry Noone, district director of the Georgetown-based Northeast Massachusetts Mosquito Control and Wetlands Management District, which runs the greenhead program.
That works out to $2,500 to construct the boxes at $125 per box, and then $82 per season per trap for repairs, replacement, storage and deployment.
Noone said if Gloucester comes aboard with a three-year contract, the initial upfront cost would go away and the cost would be $82 per trap per year to maintain the boxes. Every municipality in the program has a three-year contract, Noone said.
Eventually, the number of box traps could rise to 58, which would increase costs.
Gloucester was part of the greenhead program in the 1970s and 1980s, when it set out as many as 58 box traps. Noone did not know why Gloucester left the program.
Plan’s goals
The goal of deploying box traps is not to eradicate the greenheads (Tabanus nigrovittatus) but to lessen their prevalence from June to September, and to improve quality of life for residents and tourists.
The board heard a presentation from Thomas Quinn, a Gloucester Police patrolman who brought the idea to the Board of Health, and Noone.
“Every summer, the salt marshes along the Annisquam River is inundated with these biting insects,” Quinn said, adding the greenheads are not only a nuisance, they can take a bite out of the local economy — impacting real estate values, while limiting beach and golf course usage and other outdoor recreational activities.
Quinn said while greenheads do not transmit disease, they are a quality of life issue, as some people suffer severe allergic reactions to their bites.
So far, the North Shore Greenhead Fly Control program has set 409 traps in Essex County, including 40 in Essex, four in Manchester, 200 in Ipswich, 87 in Newbury, 25 in Saugus, 13 in Newburyport and 40 in Salisbury.
How traps work
The box trap uses the greenhead’s behavior to trap them. The 4-foot-tall boxes with legs mimic a grazing animal, enticing the greenheads to bite the underbelly of the trap, where there is a small opening. The flies enter and then get stuck, according to the program’s website.
In 1992, the program added the pesticide Octenol, also known as mushroom alcohol, to increase the number of greenheads trapped. The chemical is used to attract, not kill the greenheads.
Board of Health member Kelley Hiland asked if there were any environmental or health concerns about the chemical bait.
Noone said the chemical is contained in a 1/2- by 1/2-inch wafer wrapped in plastic with some holes cut into it. The wafer is attached inside the trap, which is bolted shut. Traps are usually set in areas hard to reach by people.
The program also uses half the recommended amount of Octenol and gets the same results, Noone said. There have been no issues with field technicians using the chemical and Noone said he has not fielded any complaints.
“When released into air, Octenol is not harmful to humans, to other non-target organisms, or to the environment,” according to an Octenol fact sheet from the U.S. Environmental Protection Agency.
Looking ahead
Noone said he has 20 traps built that Gloucester could use this season. Quinn said the plan would be to set the traps starting at the mouth of the Jones River toward Wingaersheek Beach with traps also set by Stone Pier where a lot of kayakers frequent.
Shellfish Constable Peter Seminara said he supports the idea.
“I’m on that river for half of my year and the greenheads are a major nuisance,” Seminara said. He offered to scout out locations to place the traps if the city moves forward with the plan.
Max Schenk, the city’s health director, said the ultimate decision for moving ahead lies with the Verga administration and City Council as the city enters budget season.
The Board of Health voted to support the implementation of 58 greenhead traps, starting with 20 box traps this season, with a three-year contract to keep the price down.
The board also voted that the greenfly control plan go through the Conservation Commission’s Request for Determination of Applicability process to determine if the installation of the boxes would require further regulation under wetland protection regulations.
Ethan Forman may be contacted at 978-675-2714, or eforman@gloucestertimes.com.
