Tag Archives: Black flies

Biting Black Flies on San Juan Island

This little critter landed on me the morning of August 14, 2021 (with a few friends). I managed to collect the specimen for a photo op session. AND, I let it bite me. It felt like it was sawing into my skin. I have a pretty high pain tolerance though, so it wasn’t so awful. My husband suggested I save the specimen in case I came down with any weird disease!

I have it in a vial on my desk. ID…for starters, it’s a fly (Diptera). This is a black fly (Simulium sp.) and I’ve found the larvae in the seasonal stream near our house before. At some point, I’ll write up a better post for you about these, but for today, you can watch as this female uses her serrated mouthparts to cut through my skin and take a blood meal. She’ll use the protein to help her with egg development.

Black Fly (Simulium sp) – San Juan Island August 14, 2021
Black Fly (Simulium sp) – San Juan Island August 14, 2021
Black fly (Simulium sp) biting my finger
April 8, 2020 – San Juan Island, WA – Black Fly larvae in stream
April 8, 2020 – San Juan Island, WA – Black Fly larvae in stream

My recommendation if you’re visiting or planning to visit the San Juan Islands in summertime is to bring long sleeves and wear long pants. With climate change, my guess is we will have more biting flies out in the summer evenings.

More about black flies on BugGuide – https://bugguide.net/node/view/16613

Thanks for reading!