Mosquito and Tick Information

mosquito on a leaf

Mosquito and Tick Control and Related Health Concerns

2020 Information

2020 NEMMC Best Management Practice Plan for Topsfield

Northeast Massachusetts Mosquito Control District (NEMMC) is currently, and will continue, to be conducting surveillance, mapping, and treatment of mosquito breeding sites in town. These sites are often in wooded areas and often accessed through residential properties. This is a standard procedure that is conducted in our municipality by NEMMC personnel each year during spring and summer seasons. NEMMC personnel can be identified by their logo patch on their clothing, white state vehicle, and business card or employee identification card. To learn more about NEMMC and mosquito control measures, please visit their website or call their office at (978) 352-2800.

2019 Information

NEMMC Mosquito Testing Season concluded October 2, 2019. A hard, killing frost during the weekend of November 8 and 9, 2019 signalled the end of mosquito season in Topsfield.

IMPORTANT NOTICE: Northeast Massachusetts Mosquito Control conducted truck mounted street spraying on September 23, 2019 and barrier spraying at Steward School, Proctor School and the Town Ballfields on Wednesday evening, September 25, 2019 between the hours of 6:45 PM and 10:00 PM


Only a  hard frost will eliminate the risk of EEE and WNV in our community. A hard, or killing, frost  is defined meteorologically as two consecutive hours of temperatures below  28 degrees Farenheit or three hours below 32 degrees Farenheit. The MDPH arbovirus temperature map may be found at

Please note that the process to request exclusion from mosquito spraying has changed as of March, 2017.

All requests for mosquito spray exclusion must go through the Massachusetts Department of Agricultural Resources (MDAR) via the downloadable form or the online request portal at the MDAR Website.

Residents are no longer required to send a certified letter to the Town Clerk to request mosquito spray exclusion.

Please click here to visit the MDAR website with information, downloadable form and online request portal.

  • Click here to read the 2019 Best Management Practice Plan
  • Click here to read the 2019 NEMMC Integrated Pest and Vector Management Plan
  • Click here to view the current MDPH  EEE/WNV Risk Ma

Click here to read the Superintendent's letter to school families issued 9/19/19.

Precautions against Mosquito-Borne illness:
  1. Be aware that mosquitoes are most active between dusk and dawn. Take precautions to minimize exposure during these hours.
  2. Long sleeves and long pants can minimize risk of mosquito bites.
  3. Insect Repellents including DEET (N, N-diethyl-m-toluamide), permethrin, picaridin (KBR 3023), IR3535 or oil of lemon eucalyptus [(p-methane 3, 8-diol (PMD)] should be used according to directions.

NOTE: DEET products should not be used on infants under 2 months of age and should be used in concentrations of 30% or less on older children. Oil of lemon eucalyptus should not be used on children under three years of age. Permethrin Products are intended for use on items such a clothing, shoes, bed nets and camping gear and should not be applied directly to the skin.

       4. Remove standing water in your yard where mosquitoes may breed.

  • Topsfield's Risk Level for West Nile remains MODERATE.
  • Topsfield Board Of Health’s approach remains on surveillance and education.

Links to Information On Mosquitoes and Mosquito-Borne Illness:

Tick Borne Disease