Get ready for the tickle of those "friendly flies" 

Catepillars were peaking in 2000 and 2001 I believe.  The "friendly flies" seemed to be at a peak in 2002 when I went.  They were not our friends.

Good news: the MN DNR predicts a "normal" year for tent caterpillars, based on egg mass counts.  I did learn, however, that mild winters do favor these pests, so if this pattern continues we'll probably have one of those years we'd like to forget about, sooner than later.

Check it out --
(You need to Login or Register to view media files and links)

prouboy

Totally harmless but very "clingy" and persistent.  They were imported to wage war on the tent caterpillars, I guess ( ) they lay their eggs on the caterpillar and the larva consume it?  Must be why the next year they (flies) are so plentiful.  Anyway, not an issue unless you are ticklish 

If you haven't experienced them, yes, they are harmless and annoying. 

If you have, they can be downright awful!  NOTHING makes us end a trip early.  We have done it twice in forty years.  Once when my husband (an insulin-dependent diabetic) had some really nasty blisters on his feet that needed medical attention and we had torrential rains on the next-to-last day of a trip, so we just went in early.  And the trip of the "friendly flies", when we sat at lunch on the next-to-last day, with hundreds of flies covering our t-shirts, our hats, our skin, our food, our packs. . .and said "do we really want to portage over to another lake and have another day, or shall we just call this one done?"  Looked at each other, and said, "Done".     It was nine days instead of ten.

As jjcanoeguide has said, they gather on your clothesline and leave dark spots on your sleeping bag, clean laundry, etc.  They leave dark spots on your tent.  On your t-shirts as you are wearing them.  They seem to like perspiration, and it was a warm June when we were there in 2002; my husband was wearing a white t-shirt and his back easily had 400-500 flies on it.  I would brush them away, and they would leave for about ten seconds, then they would ALL be right back!

The screen of the tent would be just black with them.  We would take refuge in the tent on a nice afternoon, just to get away from them.  And they didn't bite, they didn't hurt us, they didn't really cause any problem for us except the annoyance.  But after I had picked the second or third drowned one out of my hot chocolate. . .I somehow didn't want it anymore.   

After that trip, on our way back down the Gunflint towards Grand Marais, there were so many caterpillars dropped on the road, it was literally covered and slimy enough to almost be slippery. 

And about three days later we were visiting friends in Rochester, MN when we heard that the infestation was "OVER".  We picked the exact wrong time that year to plan our canoe trip.

It isn't a trip remembered all that fondly, but then it had some really nice moments, too.  They didn't come out until the air temperature reached about 70 degrees, so in the early morning and the late evening we were fly-free.  I loved the pre-dawn and sunrise times that trip and got some beautiful photos, had some great times on my sitting rock in Cherokee Lake writing in my journal and just enjoying the Lake view. 

There is no such thing as a bad canoe trip.  That one just wasn't one of the best ones, and if I hear that it is a "friendly fly" year, I will try to time my permit for fall!