Why does “gestalt” identification works with some bark beetles? Species of the genus Diuncus from Papua New Guinea, for example, differ in characters that are difficult to code as discrete, but anybody with one of these specimens in hand could immediately tell the species by its shape and color if the whole diversity were laid out as in this example. A new mobile app developed by entomologists at the Forest Entomology lab at the University of Florida and the U.S. Department of Agriculture-Agricultural Research Service’s Systematic Entomology Laboratory aims to train users in bark beetle identification. (Photo courtesy of Jiri Hulcr, Ph.D.)

By Jiri Hulcr, Ph.D.

Every entomologist has been through the purgatory of identification keys. I don’t know who coined the following sentence, but it is true: Entomological keys are written by those who don’t need them for those who can’t use them.

So why not try something else?

Jiri Hulcr, Ph.D.

Observe an entomologist trying to identify an unknown bug in a museum collection: They don’t reach out for a dusty key in the bookshelf. Instead, they glance over the drawers where the diversity of shapes is laid out, narrowing down the similarity until they have a match, or at least a close group. This iterative process is so efficient because it harnesses the power of human pattern and shape recognition.

Insect identification has relied on dichotomous keys, and for a good reason. They offer a methodical way to identify almost anything with confidence. But they are hard to use, because the human brain is not particularly good at logic. At the same time, we have mostly ignored the incredible 3D analysis machine that our brain uses every second of our waking life.

What differentiates the expert from the rest of us is their “gestalt”—another word for the experience of having seen a particular shape hundreds of times and having subjectively classified it. If a machine can be trained to recognize thousands of human faces, surely humans can pick up simple differences among the bark beetle heads and butts.

But learning is hard, too, so how do we make the learning process fun? Thus began the idea of a gestalt-sharpening game.

The Forest Entomology lab at the University of Florida and the U.S. Department of Agriculture-Agricultural Research Service’s Systematic Entomology Laboratory are proud to introduce Eruditus, the first fun bark beetle app. Based on high-quality photos of hundreds of bark beetle species, the app allows you to either play a beetle identification game or browse through the bewildering diversity of morphologies in the Bark Beetle Library. Bark beetle lovers, now you have something to do on your daily bus to work or before bedtime: train your circuits! You can get the app for free at the App Store for iOS and at the Google Play Store for Android.

Based on high-quality photos of hundreds of bark beetle species, the Eruditus app allows users to either play a beetle identification game or browse through the bewildering diversity of morphologies in the Bark Beetle Library. Shown here (left to right) are the title page, game interface, game score, and Bark Beetle Library interface. (Screenshots courtesy of Jiri Hulcr, Ph.D.)

Bark beetles are often perceived as difficult to identify—a group that’s closed to anyone but a few specialists. We beg to differ. Bark beetles abound with different shapes, colors, and hairiness. Although most of their little bodies are constrained to look like a tiny cylinder, their front and rear parts are free to evolve, and they do get phantasmagorical. Perhaps the real reason why novices perceive bark beetles as difficult to identify is the way we have taught them. With a zealous focus on the number of antennal segments or bumps on elytral declivity, it’s no wonder that identification seems difficult, arcane, and no fun. But it does not have to be so; whoever enters the magical world of bark beetles rarely leaves, whether they are an expert or a hobbyist. There are hundreds of bark beetle fans around the world, and they find the beetles amazing (check out the bark beetle fan group Frass & Noodles on Facebook).

We hope that even uninitiated folks will now find it easier to get over the initial learning curve by playing a game that builds their gestalt. The first version of the app has several hundred images, and we admit that it does not even begin to cover the diversity of bark beetles. For a real training app, we need more pictures. Thousands of them! Would you like to see your own bark beetle photographs in the app? If you have a collection of lateral or dorsal deep-focus (stacked) images of bark beetles with a white background, please get in touch so that we can keep building the app together.

The app’s name, Eruditus, was suggested by Dr. James Skelton, a bark beetle and pun expert at the College of William & Mary. It is inspired by the species epithet of the most abundant bark beetle in the world, which you have probably never seen.

Would you like to have an app developed for your favorite entomology topic? It is a relatively simple process, as long as you find a good developer. We worked with Dust Productions, Inc. We provided the idea for the structure (illustrated with hypothetical screenshots), all the data and images, several rounds of reviews at the end, and of course the funding. The developer took care of the rest.

Here are a few words for bark beetle nerds. The tribes list is complete, with the exception of Amphiscolytini and Carphodicticini, which are so rare that few mortals ever encounter them. We have also not included the Platypodinae. The tribal classification of these “other” ambrosia weevils is a polyphyletic mess. At this time, their genus names would not reflect their morphological similarity, and therefore a resource that relies on gestalt training would not work.

Jiri Hulcr, Ph.D., is an associate professor with the School of Forest Resources and Conservation, University of Florida, Gainesville, Florida. E-mail: hulcr@ufl.edu