South Twin Cities metro besieged by aggressive, biting gnats
Through the end of last week, the Metropolitan Mosquito Control District (MMCD) had received just a handful of calls about gnats, said public affairs coordinator Alex Carlson. Less than five.
Now, they've logged more than 100.
That's right: Gnats are back out in the Twin Cities.
MMCD said it's been getting "lots of calls" about the gnats - actually called "black flies" - recently, with most coming from Burnsville, Savage and Bloomington, Carlson said. They've also received reports of black flies from areas near streams in Minneapolis, Hastings and Maple Grove.
"Our sweeps are finding a lot of activity near Nine Mile Creek, Minnehaha, and Vermillion," he said.
These biting gnat surges are becoming a bit of a spring ritual, with similar reports over the past couple years. That includes the local debut of Simulium tuberosum in 2020 - a more aggressive species of black fly than the ones typically seen in the region.
That pesky bug is back, Carlson said, noting MMCD has found "a lot" of that particular species again in 2021. He suspects most of the calls MMCD has received are due to Simulium tuberosum, though said the standard black flies we usually get are popping up as well.
While MMCD did get permission from the DNR to treat certain areas of the metro for this aggro gnat, it doesn't cover everywhere. Meaning "there are likely streams that they are coming from that we are not treating," Carlson noted.
MMCD staffers have been out in the field collecting samples, including this lucky individual, who got to act as an attractant:
Carlson said MMCD's lab is working to identify the gathered samples from the past couple of days. MMCD will treat areas in the metro this week for black flies.
In the meantime, residents can report high levels of black flies to MMCD here. The organization also has some tips to help avoid suffering a black fly bite, which can cause welts.
- Since black flies like darker colors, wear light-colored clothing
- Cover as much skin as possible - they won't bite through clothes
- Peak feeding time is mid-morning and afternoon, so try to avoid those periods
- Scented shampoo, deodorant and perfume and attract black flies
- Insect repellants can be effective, though aren't foolproof - use an EPA-approved repellant, with DEET or other active ingredients (such as picaridin and lemon oil of eucalyptus)
If you can endure for a bit, the biting gnats should ease up. The lifespan of a black fly is generally only two or three weeks.