Saturday, June 3, 2023

A smattering of flies

I spent yesterday morning afield in Crawford County, Ohio, casing field trip sites with Chelsea Gottfried for the upcoming Ohio Odonata Society's annual meeting. We found some notable dragons, including two sites for Emerald Spreadwing (Lestes dryas) and a new site for the state-listed Dusky Clubtail (Gomphus spicatus).

As usual, there were distractions, not the least of which were flies. The Dipteran family is massive and endlessly fascinating, with some 125,000 species thus far described worldwide. Some authorities believe there could be one million species. It is for sure that we know far less about flies than we might think we do.

As macro subjects, flies deliver. While many species are so small as to not warrant notice - at least to many people - the macro lens can pull in elaborate details in all their glory. I present four fly species from yesterday's trek. All were shot with the Canon 100mm f/2.8L macro lens (a MAJOR workhorse for me), the Canon R5 and Canon 600 Speedlite.

A horsefly in the genus Hybomitra hovers in a woodland glade. Several of its comrades hovered nearby. They would hover in the same spot for extended periods, occasionally dashing towards another fly that impinged on its air space. This hovering behavior is part of the male courtship display, and apparently Hybomitra horseflies typically do this in the early morning hours, which is when we made this observation. Note the crazy eyes! Many horseflies have brilliantly colored eyes, and in general this group is very showy. People, trite and superficial as we can be, mostly malign horseflies due to the handful of species that can deliver punishing bites to us. The biters are female, males such as the one in my photo do not bite/suck blood from mammals. The Tabanidae (horsefly family) is an ancient lineage and so far, nearly 4,500 species have been found worldwide.

A fly in the genus Eutrichota grooms itself. When I first saw this one, I thought it was a tachinid fly due to the conspicuous bristles. But no, if I've got the genus right (I have no idea as to species), it is one of the root-maggot flies. Apparently, the adults use rodent burrows as nest sites, at least with some species.

A marsh fly in the genus Tetanocera shows off its utterly bizarre head and face. It appears to be wearing a gas mask. Marsh flies, as larvae, are parasites of snails and in some case, slugs.

Finally, for your viewing pleasure, a Golden Dung Fly (Scaphiophus stercoraria). It's a fairly large species and resplendent in its coat of golden-yellow fur. The common name stems from the larva's bailiwick: dung. From this ignominious beginning springs the beauty above. While I was passingly familiar with Golden Dung Flies, I did not know that adults are predators of other fly species. The one in the image has dispatched and is sucking the contents from some unknown fly victim.


Jack and Brenda said...

Some really amazing photos. You did a great job of getting a nice depth of field!

Jim McCormac said...

Thank you! F/13 :-)

Southern Ohio Hiker said...

I guess if I was given a choice between eating dung or another fly I would choose the fly. I love being a human.