Several factors have conspired to create a perfect storm of unrealistic expectations when it comes to insect identification these days. The digital age has meant that entomologists are more accessible to the general public than ever before; that it is possible to capture a stunning image with a smartphone; and that social media has accelerated the broadcast of incorrect information. Naturalists who are branching out from the pursuit of vertebrates seem stunned to learn that not every insect or spider can be identified to species from visuals alone. Here are the top reasons why you may fail to achieve a species-level identification from myself, or any other entomologist or arachnologist online.
You have not supplied an image. Few insects are so distinctive that a verbal or written description alone is sufficient to make an identification. The Wheel Bug, Arilus cristatus is one exception that comes to mind. Wheel Bug adult The image is of exceedingly poor quality. Many insects and spiders are simply too small, and/or move too fast to allow you to capture a clear image. That is not your fault, you are doing the best you can. However, standing across the room and taking a picture of the spider on the opposite wall is your choice, and the image results won’t be pretty. I often kid people that they must have used Google Earth for the image in order to maintain a safe distance. You did not furnish location information. The geographic location where the arthropod was spotted can be of paramount importance in eliminating some “suspects” and narrowing the possibilities of what the creature could be. The more precise the location the better, as even a state or province may not be of much help. Your insect is in an immature stage. Many immature stages such as eggs, larvae (caterpillars, grubs, maggots, etc.), nymphs, and pupae simply cannot be identified much beyond a family-level of classification. In many cases, we simply don’t know what a species looks like in its youth, unless it is something of economic importance. Try rearing the insect to adulthood if possible, documenting the different stages. You could easily make important discoveries this way. Yeah, I got nothin' You don’t know the host plant (for an herbivorous insect). Many insects are best identified by association with a particular plant, but perhaps you found your specimen on a fencepost, or it landed on a plant that it does not feed on. These are circumstances over which you obviously have no control, but it may mean you won’t get a specific ID this time around. Overestimating size. Insects and spiders are very good at creating the illusion that they are much larger than they appear. People prone to arachnophobia or entomophobia then inflate the size even more until you have the bug equivalent of a fish story. When in doubt, don’t even bother mentioning size. Many species look alike. You would be amazed how many insects, even from different families, can look essentially identical. Add to that the amazing degrees of mimicry whereby harmless insects resemble stinging insects, and it becomes a real challenge for the novice to achieve an identification even to an “order” level of classification. Bumble Bee Not bumble bee (robber fly) Visuals alone may be insufficient. This problem arose for myself last week when I sought the identification of a jewel beetle in the family Buprestidae. Turns out there are several species in the genus Agrilus that feed on oak, and are slate gray with a metallic head and thorax. Who knew? Cryptic species. It is not just the digital age that has revolutionized our expectations for identification. The age of molecular biology, with DNA analysis, has revealed that what we once thought was a single species may in fact be several species, all of which are visually identical, but are vastly different at the genetic level. Consequently, “species groups” have entered our vocabulary. Photuris sp. fireflies are best identified by the flash patterns they blink at night Taxonomy changes frequently. Entomologists are constantly revising the classification of insects, from species-level to order level as they gain new insights into phylogenetic relationships. Did you know, for example, that cockroaches and termites are now in the same order? It’s true! Not because they can both be pests, but because we now know they are more closely related than previously thought. So, the identification you get today may not stand up to the test of time. Proliferation of field guides. More field guides is never a bad thing, but people accustomed to bird, mammal, and reptile guides that include every species for a given geographical area has created an unrealistic expectation of the same when it comes to invertebrates. It would take an encyclopedia of several volumes to cover every species in a single order (or even family in some cases). Limited expertise of the expert being consulted. Most entomologists are specialists on a single order, or even family or genus, of insects. Consequently, when confronted with something unfamiliar, they are not easily able to offer a definitive answer. I can count on one hand the number of entomologists with an impressive ability to identify almost anything (and I am not one of them). Please bear that in mind when making your identification request.
Considering everything that can go wrong, it is a minor miracle that most folks who submit requests for identification end up being satisfied with the results. We aim to please, and are happy to make your day by solving whatever was, um, “bugging” you.