Tuesday, June 3, 2014

Fly Month

This morning, as I was conducting the sixth of the eight forest breeding bird census counts that I do each year in late spring and early summer, I noticed my first hoverflies of the year cruising a sunny patch of woodland understory.

Adult hoverflies are a bit intimidating because superficially they resemble wasps or bees.  While the larvae of most species are carnivorous, the adults are exclusively nectar feeders (hence the family's other common name: flowerfly [family Syrphidae]) so I have no reason to be anxious. 

As the forest birds settle into their territories, the forest quiets down quite a bit, providing me opportunities to observe other wildlife like the hoverflies.  This morning, there were four of the flies in the patch.  All were facing the same direction, and they all "hung" in the air, lined up side-by-side about eight inches apart, patrolling their own tiny patch of air space.  Occasionally, one would break ranks for a second, zooming away (usually backwards!) but returning almost instantly to take up exactly as it had left off.  Their world is unfathomable to me, but they are endlessly fascinating to watch.                                                                   
I refer to June as Fly Month. It's the month when mosquitoes make their first appearance and when deer flies are most maddeningly abundant.  Furthermore, I'm no fan of hot weather, so the addition of pestiferous flies to the mix only makes June all the more unpleasant.  Of course, the forest nesting birds will soon have plenty of new mouths to fill, so perhaps I shouldn't complain about the superabundant dipterans too much.


packrat said...

We saw a bunch of hoverflies in the Sacramento Mountains, Scott. They are absolutely fascinating, displaying aviator skills that are beyond comprehension. They all seem highly curious about the human animal, too, and their buzz is slightly intimidating until you get a look at what's buzzing you. For the longest time I thought they were a type of small bee.

Scott said...

I couldn't agree with you more, Packrat, about hoverflies' aerial skills, interest in humans, and ability to look intimidating on the wing.

I'd forgotten that the larvae of many species are aquatic (or semi-aquatic)--this from an old aquatic entomologist; I should be ashamed of myself. The species most highly adapted to an aquatic existence have a long breathing tube that they extend above the surface of the water to enable them to get oxygen when they're living in the most foul, oxygen-poor and polluted water. These larvae colloquially are called "rat-tailed maggots"--aptly named!

Mark P said...

I tried to comment a few days ago with my phone, but it didn't seem to work. I was going to say that we have hoverflies here, and Zeke the dog really doesn't like them. Also, I'm completely with you on hot weather.

Scott said...

Mark: The flies don't actually bother Zeke, do they? It must be an existential thing--he just doesn't like flies hanging there almost within snapping distance but too aerodynamic to actually catch.