Wild Side: Insect IDs

The internet allows everyone to take up citizen science.

Online resources allowed the author to identify this fly as Orbellia petersoni. — Matt Pelikan

Twenty years ago, it would have been nearly impossible for an amateur naturalist like me to study insects with any success. A few groups, to be sure — butterflies and dragonflies, for example — were obvious and charismatic enough so that usable field guides had been created. But for the vast majority of insects, the basic act of identification required use of daunting scientific keys.

These so-called “dichotomous keys” take you through a series of yes-or-no questions, with each question zeroing in a little more closely on a precise identification. There’s nothing magical about the process; indeed, it’s designed to be foolproof and objective. But it requires a detailed knowledge of the anatomy of the insect you’re trying to identify. And it generally requires a dead specimen to examine, and a microscope to view it with.

Yes or no: Does the anepimeron have a long bristle extending posteriorly beyond the middle of the lower calypter? Not many amateurs, then or now, have the patience or background knowledge to answer questions like that! And until recently, scientific keys, even if you really wanted to use one, were difficult to find and access.

But a set of interrelated changes have made identification far easier since then. The internet and in particular social media have made it possible for casual naturalists to communicate with world-class experts. Vast amounts of information on insect ID, from photo databases to digital versions of dichotomous keys, has accumulated on public websites. Digital photography has made it possible for even beginning photographers to capture stunning images of tiny invertebrates. There are even apps and algorithms that do a pretty good job of automatically identifying wildlife photos even if the user has no knowledge at all (the website iNaturalist.org is a good example).

A personal experience illustrates how modern technology leverages whatever personal knowledge an observer may have. A few years ago, in December, I photographed a tiny fly on the inside of a window of our house. Looking at the photos, I saw an elongated fly about the size of a grain of rice, with a small, round head, short antennae, and a row of well-developed bristles along the leading edge of the wing. The overall appearance of the fly ruled out many major branches of the order Diptera; by scrolling through my favorite identification site, Bugguide.net, I concluded that this fly was in the family Heleomyzidae (one classic trait of this family is the presence of those wing-edge bristles).

Poking around a bit in Bugguide’s photo archive, I found a good match for my fly in the genus Orbellia. I posted the photo on Facebook with my tentative ID; within hours, a Facebook friend in Europe, who happens to be an authority on Heleomyzidae, confirmed the ID. Nice! I had identified my fly to the genus level.

Fast-forward to this past December, when I photographed another, similar fly, also on the inside of a window. Recalling my previous experience and comparing the new fly photos to the old ones, I concluded I had another Orbellia on my hands. But the legs on the first Orbellia were yellow, and the legs on the second one black. Leg color, I knew, can be meaningful for fly identification, so I suspected I had photos of two Orbellia species.

I headed back to Bugguide.net, where I read the following about the genus Orbellia: “Probably only two species in North America, barbata with legs mostly yellow and petersoni with legs mostly dark.” In an instant, I had firmly identified two species in an obscure family of flies!

I guess I can take partial credit for this success. I noticed the flies in the first place and was able to get decent photographs. And thanks to previous work I’d done, I knew enough to recognize the flies, at least to the family level, and was astute enough to note the different leg coloration. But my minimal knowledge was hugely amplified by easy access to scientific experts and the existence of a vast, well-curated body of previous fly records.

I realize that flies are not everybody’s cup of tea. But if you’re interested in biodiversity, every species matters. (And if you’re reading this column, you’re probably interested in SOME form of wildlife!) The situation I’ve described here for fly ID applies to every other form of living thing. Advances in knowledge and technology have utterly changed the game, allowing even beginning observers to successfully learn about obscure organisms and — this is important — to feed information back into the system, making it still more powerful.

To be sure, the process isn’t effortless. And abstruse scientific knowledge is still required for some identifications; working from photos, you’re sometimes only able to ID an insect to family or genus. But we are in the age of “citizen science;” barriers that inhibited wildlife study just a few years ago are collapsing, turning anyone with interest and a cell phone camera into a contributing member of the scientific community. It’s a beautiful thing.