Letter On Mosquito Control: “Upton BOH should consider another approach”


On Thursday May 5th the participants at Upton’s annual town meeting will vote to decide if the town should join the Central Massachusetts Mosquito Control Project (CMMCP). The CMMCP is one of 11 mosquito control districts in Massachusetts. It currently operates in 41 towns within an 89 town service area. Upton, along with Mendon and Uxbridge, voted against joining in 2013.  Grafton and Bolton dropped out of the program in recent years.

The project offers the following services to towns: application of pesticides to kill juvenile (larvae) and adult mosquitoes, monitoring mosquitoes for human disease like west Nile virus and EEE, habitat manipulation to reduce standing water, tire removal, and education. The program provides some benefits but on balance is a poor choice for Upton.  Reasons to oppose the joining the CMMCP include the following:

  1. Lack of flexibility: the CMMCP offers towns a fixed program. This is a matter of policy set by the small (5 member) Board of Commissioners which runs the CMMCP, none of whom live in Upton.  Other Massachusetts mosquito control districts offer flexible programs.
  2. The central element of the CMMCP program is adulticiding – spraying pesticides to kill adult mosquitoes, often from truck mounted sprayers. This includes using town funds to spray on private land at the owner’s request. Spraying occurs whether or not there is a high risk of disease transmission. In 2015, the CMMCP sprayed 181,522 acres. Widespread spraying occurred in all towns the CMMCP served despite the fact that disease carrying mosquitoes were found in just 9 towns and 11 of 1319 mosquito samples.
  3. State law gives the CMMCP the right to apply pesticides on private land without the landowner’s permission. If someone does not want pesticides applied on their property they must opt out by sending a letter to the CMMCP prior to March 1 of each year. They must also mark their property borders at 50 ft. intervals.  In 2015, more than 2000 people opted out the CMMCP program.
  4. The pesticides CMMCP uses to kill adult mosquitoes also kill other insects. Little is known about the effect of widespread long-term pesticide spraying on insect biodiversity. Some studies have shown that butterflies are a risk from pesticide residues on vegetation. Bees and other pollinators may also be affected. The effect on the myriad of small insects with which we share our world (moths, leafhoppers, harmless wasps, midges, etc.) is largely unknown.  The morality of killing large numbers of non-target insects to control mosquitoes is debatable.
  5. The spraying program is likely to have only short-term benefits. A study done by the CMMCP in 2011 showed that the effect of spraying on mosquito abundance lasted for just several days. The study concluded:  “The trials of this study showed that control was achieved for a few nights before the mosquito populations returned to pre-application levels…. Indications are that the findings in this study were primarily the result of repopulation by neighboring mosquito populations”.
  6. The CMRCP also uses pesticides (larvicides) to kill mosquito larvae in standing water, including wetlands and vernal pools. Mosquito larvae are a key component of the food web in vernal pools where they are preyed upon by many invertebrates such as dragonfly larvae.  The effect of applying mosquito larvicides on vernal pool communities has not been adequately studied.
  7. CMMCP conducts “restoration” projects aimed at reducing standing water where mosquitoes breed. Although some of these projects, such as ditch and culvert maintenance are innocuous, others such as clearing streams and draining wetlands and beaver ponds have negative effects on habitat. Measures to improve drainage also adversely affect other valuable wetland functions such as groundwater recharge and flood control.  If conducted by the CMMCP, these sorts of projects are entirely exempt from review under the state Wetlands Protection Act and town wetland protection and storm water bylaws.
  8. The pesticides CMRCP uses to control adult mosquitoes are approved for use by the USEPA. Used as directed the pesticides are believed to have acceptable (tolerable) risk on human health based on the available scientific information. EPA approval, however, does not mean there is no risk and some risks may be unknown or underestimated.

The Upton Board of Health should consider another approach.

  1. First emphasize personal protection to reduce the risk of mosquito bites. This includes staying indoors at dawn and dusk and in evening, which are peak mosquito biting times, wearing long-sleeved shirts and long pants when outdoors, using insect repellents, and fixing holes in window screens.
  2. Demand reforms in the CMMCP. The program should offer Upton a flexible mosquito control program, one in which the people decide which elements of the program are appropriate for their community.  Currently to take advantage of desirable CMMCP services such as mosquito monitoring, a town must accept widespread spraying to control adult mosquitoes. Obtaining reforms may require placing political pressure on the existing CMMCP commission and the state officials who appoint its members.  Without pressure, the CMMCP is unlikely to reduce its spraying program because, arguably, spraying is the organization’s main “profit” center.
  3. Develop an Upton led alternative to the CMMCP. This year the town of Westminster annual town meeting is considering hiring a private contractor to provide a flexible menu of mosquito control services at a lower cost.

Ideally a locally developed mosquito control program would include the following elements

  1. Public education with an emphasis on personal protection and eliminating mosquito breeding sites near homes (BOH).
  2. Mosquito monitoring. (Private Contractor).
  3. Larvicide application to catch basins and ditches (Private Contractor or licensed Upton DPW personnel).
  4. Spraying to control adult mosquitoes at only high use areas such as athletic fields (Private Contractor). Homeowners intent on using pesticides to control mosquitoes on their property could hire a private service at no expense to town taxpayers.
  5. No pesticide application on private property without the owner’s permission unless allowed by state law when a public health emergency exists.
  6. No application of larvicides to vernal pools unless allowed by state law when a public health emergency exists.
  7. A tire (breeding habitat) removal program organized by Board of Heath and Town DPW.
  8. No draining or other physical alteration of wetlands and streams to control mosquitoes without review and approval by the Conservation Commission.

This program would protect the citizens of Upton, be cost effective, protect the environment, respect private property, preserve local control and oversight, and send a message to the CMMCP that it is time for a change.

Respectively submitted by:

Mike Penko

Vice-Chair, Upton Conservation Commission


  1. I completely agree with Mike’s comments and wish to echo what Lara said. Hear, hear!

  2. Here Hear! Well said. This program we are voting on is so flawed it’s hard to know where to begin. You do a great job emphasizing some of these points. Thank you Mike.

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