Enjoying the outdoors during black fly season

by Shelby Wood

I love being outside. Many of my favorite activities take place outdoors: riding my horse, walking my dogs, running with friends, picnics, sitting on the dock, etc. All of these activities are much less enjoyable when black fly season comes into play. My skin is very reactive (I’d guess I’m allergic), and I get wild looking, painful welts following a black fly bite. As you can imagine it makes my enjoyment of the outdoors much more difficult this time of year. So if, like me, your ability to enjoy being outside during black fly season diminishes, these are some tips I’ve learned in researching how to avoid black fly bites.

According to the Maryland Department of Agriculture:

  • Engage in outdoor activities mid-day when black flies are less active.
  • Avoid outdoors on humid, cloudy and warm days right before thunderstorms; black flies are most aggressive at this time.
  • Wear light colored clothing, as black flies are attracted to darker colors.
  • Tuck in clothing, and wear long sleeves and pants.
  • Use insect nets.
  • Apply insect repellents, and reapply every few hours.


The UNH Extension entomologist, Dr. Alan T. Eaton Further shares:

  • Zippered front shirts are often better able to keep black flies out as opposed to button up shirts.
  • Most active black fly periods are “from 4:00 to 7:00 in the late afternoon and early evening, or until the sun falls below the horizon.”
  • Black flies are known to crawl under socks, up sleeves and up pant legs. Focusing bug spray on ankles, wrists and the belt area can help in preventing this.

(Eaton, 2022)

Dr. Eaton also has a resource available through the UNH Extension, explaining the different types of insect repellents as well as information on the efficacy of the various options. To see the information shared by Dr. Eaton visit the UNH Extension resource.

Tip from a local hiking enthusiast:

  • Be outdoors on breezy or full sun days, as they usually retreat to the woods during the heat of the midday sun.

Fret not! These dreadful bugs are gone  around Father’s Day.

Works Cited:

“Black Fly Personal Protection.” Mda.Maryland.Gov, mda.maryland.gov/plants-pests/Documents/blackfly.protection.pdf. Accessed 24 May 2023.

Eaton, Alan T. “Insect Repellents – Extension | University of New Hampshire.” UNH Extension , extension.unh.edu/sites/default/files/migrated_unmanaged_files/Resource000963_Rep1073.pdf. Accessed 24 May 2023.

Eaton, Alan. “Black Flies [Fact Sheet].” UNH Extension, 13 May 2022, extension.unh.edu/resource/black-flies-fact-sheet.

If you have a wellness themed topic you would like to share or learn more about, and/or blog/vlog about as an expert in a health/wellness related field, please reach out to shelby@cclyme.org. 

Shelby Wood
Manager of Volunteer Participation
CommunityCare of Lyme