It was one of those rare Saturday mornings. The morning sun was bright but not hot, the sky was a pure shade of robin egg blue, and I actually had part of the day off. I used that part of the day to try out a garage sale in Dundee, a small town along the River Raisin to the west of my home. Unfortunately, the “sale” was anything but – retail and eBay prices were the norm– so I turned back and took the scenic route back home.
The road follows along the wooded high north bank of the river past farm houses, barns, and fields. It is a country drive. Long morning shadows over the pavement created a flickering effect, as if my traveling vehicle was part of an old movie scene. Small plumes of smoke were in evidence along the right hand side of the road wherever a shaft of sunlight was bordered by deep shade. Some of the plumes drifted over the road and dissolved as my truck passed through them while others danced and wavered as if being pushed by gusts of wind even though the morning was still and windless.
It is normal to suppose that where there is smoke there is fire, but on this occasion the smoke plumes were actually swarms of dancing flies called midges (“where there is smoke there is flies”, or something like that). I stopped to photograph one of the larger swarms at a spot located in someone’s front yard. Fortunately the occupants didn’t emerge from their house to confront the kneeling naturalist taking pictures of air. Had they of done so, I would have provided the following explanation…
When conditions are right – in other words still, clear, and sunny –tiny Chironomid midges are stimulated into love dancing. The tiny creatures emerge from the river and gather into huge flying swarms. These clusters consist of male flies only. The stag parties collect over some feature of the landscape, such as a rock or a patch of ground illuminated by a shaft of sunlight, and there they engage in a rhythmic series of up and down movements (see above and here). Hopefully this explanation would have worked to prevent enforcement of trespassing regulations!
The vacillating dance swarm moved like the northern lights as they wavered to and fro (see movie sequence here). They took on the appearance of a super-being greater than the sum of its minuscule parts. All this activity generates a low humming sound which attracts the females. Upon hearing the wing vibrations of an approaching female, a male will dart out of the swarm, intercept her in mid air, and mate with her on the spot. This activity will extend into the late morning and then resume at the other end of the day when the sun is again at a low angle.
Midges are members of the fly family. As larvae they live their life as aquatic residents living within small silken tubes attached to bottom vegetation and pebbles. They feed on microscopic plants within the water column. Upon emerging, midges immediately take to the air and head for the dance floor, which is why these dancing swarms are always located near permanent water. The adults look very much like mosquitoes, but are much smaller and do not bite humans. The males and females look similar, but the males are easily distinguished by their plume-like antennae.
Not wanting to hang around the front yard too long (people in the country have shotguns, you know) I clicked my pictures and departed. I didn’t have time to grab specimens but I was able to find a few of the creatures plastered on my turn signal lights. So, rather than leave you with only a movie of a swarm and a verbal description of a Dancing Midge, I can show you a detail shot of one of the dancing flies captured in mid step (see below). Framed against the orange background of the light, this portrait looks very much like one of those amber trapped insect fossils. It is a still life of a stilled life.