PITTSFIELD, Mass. — Last year was the "season that never was" when it came to mosquito control.

 

But this year, Berkshire County Mosquito Control Project Superintendent Christopher Horton is back at it with approval for the 2017 plan from the Board of Health.

 

Horton said the program will remain mostly unchanged as in previous years with the exception of a new barrier chemical and a new state process for opting properties out of treatments. 

 

"All of our no-spray requests are going to have to be replaced through the new process," Horton told the Board of Health.

 

Previously, residents had the ability to ask Horton to exempt their property from adulticide spraying. He said the list had grown to close to 150 residents doing so and that was kept in-house until the homeowners requested a change. That was somewhat complicated, Horton said, because properties would change hands and the project wouldn't know.

 

Now, the state is taking over that process so anyone who has opted out will need to do that again. It will take two weeks after filing the form, either online or on paper, with the state to be included on the list and then residents are also required to place signs reading "no spray" on trees or poles visible from the street every 50 feet along a property line.

 

"They are going to have to do the process and the other part of it is there is a marking component," Horton said.

 

The other change is a switch to Mavrik as a barrier product, which is placed on individual properties. Previously the project used Flit, and Horton says the current inventory of that will be used up and the project will purchase Mavrik instead.

 

"It is easier to apply, safer for the applicator, and safer for the pollinators after it is applied," Horton said, particularly citing bees as being less affected by the chemicals.

 

Otherwise, the program is ongoing. It starts with observation, followed by source reduction. The project looks to eliminate standing pools of water where mosquitoes breed — inside of tires is a common example. From there, they use a larvicide control at mosquito breeding grounds. 

 

The project will capture mosquitoes throughout the city and send the samples to the state for testing. The state is looking for West Nile virus and Eastern equine encephalitis. If those are found or the population numbers reach certain thresholds, then the truck will be brought out to spray portions of the city where those thresholds or diseases were hit.

 

Last year, the nearly statewide drought and dry weather meant fewer mosquitoes. That made the season "manageable," Horton said. But the project did do larva control on 220 acres, treated 4,052 catch basins, and collected 136 samples — one of those finding West Nile virus.

 

"We responded to that isolation with an adulticide for a one-mile radius," Horton said.

 

Other properties can request adulticide application if there are nuisance issues or the mosquito population hit those marks so in total 1,610 acres of adulticide were sprayed. Board of Health Chairman Jay Green added that while 1,610 acres were treated, only 7.8 gallons of the chemical was used.

 

"The introduction of the product is actually very minimal to treat large areas," Green said.

 

The spraying had been a contentious issue in the city in the past. Petitions had been filed asking for the halting of the spraying with opponents saying the chemical, Duet, caused health issues, impacted childhood development, and harmed wildlife. Meanwhile, they said it wasn't as effective as portrayed.

 

The Board of Health, however, said the science does not support those claims, and that the sprays have been shown to reduce the mosquito population, thus preventing diseases.

 

Both sides presented various scientific studies to support their arguments but the Board of Health has continued to operate under the program. At one time, a study group presented numerous other options to combat mosquitoes but none of those other options has been taken up in earnest.

 

There was nobody in opposition at Wednesday's meeting but Horton did touch on that debate somewhat, saying the chemicals he uses now are airborne droplets that do not have residual effects. The chemical is sprayed into the air, acting more like a gas than a liquid, and breaks down in water or light. Horton says by the time morning arrives, the chemical is already breaking down. 

 

Last year, the organization also provided 18 acres of barrier applications, inspected 347 breeding sites and 5,588 catch basins, and performed ditch maintenance in 9,500 areas.

 

But last year was somewhat of an anomaly because of the dry conditions. Horton said the organization has already used more larvicide this year than it had all last year. In April, days of rain and melting snow caused flooding, which brings out mosquitoes in floodplains.

 

The long-range forecast for this year calls for "above average temperature so that means more rapid mosquitoes," Horton said, adding that there is also a link between higher temperatures and more disease presence. But the rainfall totals appear to be average, limiting the amount of flooding. The eggs of mosquito breeds in floodplains will remain inactive until flooding.

 

The program has been in various towns in Berkshire County since 2011. There have been 58 cases of West Nile in mosquitoes and one human case. There have been six cases of EEE, which is considered a more serious virus but not as prevalent in Western Massachusetts than out east.

 

Throughout the summer, Horton and Health Director Gina Armstrong will be responsible for making decisions on when and where to spray adulticide.

 

"We don't do things automatically. All of the decisions we make is based on need," Horton said. "We are not going to spray the whole city if we have an isolation in only one part of the city."

 

Some areas of the city have much higher populations — Ward 4 residents particularly have requested additional spraying because of high mosquito numbers in the past.