Post written by Joe Ballenger

How do you know if a bug has been discovered before?

-Bridget Mendel’s First Grade Class

Entomologists have a pretty impressive ability to identify whatever’s put in front of us. It’s a major part of our job description, whether we’re working in agriculture or academia. In fact, most of the things we get asked about are about the insects people find on a daily basis.

@bridget_mendel @SciBugs That is a red palm weevil, a really important introduced pest to palm trees.

— Joe Ballenger (@Stylopidae) May 15, 2015

Knowing what these bugs are means that someone has discovered them before. Bug scientists are still finding new kinds of bugs every day…so how do we know if a bug has been found before?

Internet Groups

These groups are also really great places to find talented photographers and pretty bug pictures. This Delta wasp, a favorite genus of Joe’s, was lent to us by Stephane De Greef after it was posted in the group.

The simplest way to run a bug by an expert is to post a picture to a website where the experts hang out. There are a lot of great groups and websites which revolve around insect identification, the best of which are BugGuide, What’s that Bug?, and the Entomology Facebook group.

Good IDs can come from people in these groups, so long as you know who the experts are. The main benefit of these groups, the ease of access, is also a big drawback. Many members post IDs which aren’t very good, but most of these groups have moderators which take care of the wrong IDs.

These groups are important for scientists, as well as the general public. Scientists (like myself) who don’t specialize in identifying insects use these groups to figure out what bug is what. They’re also important to scientists who identify insects because they can look for new bugs using the data the groups have generated.

Dichotomous Keys

Scientists who identify insects as part of their daily work use documents called Dochotomous keys to identify insects through a process of elimination. Under our resources page, we have a link to a wide variety of keys.

A key starts out by asking you a very general question, for example…whether or not a bug has wings. Here’s an example:

The insect on the left, a potter wasp has wings. The insect on the right, a silverfish, does not.
Potter wasp image credit: Stephane De Greef, used with permission.
Silverfish image credit: Susannah Anderson, via Flikr.
License info: CC BY-NC-ND 2.0

The key then moves on to more specific questions. In this case, it might ask whether the waist on a particular wasp is long or short.

The wasp on the left, a potter wasp, has a long waist. The wasp on the right, a paper wasp, has a short waist.
Potter wasp image: Stephane De Greef, used with permission.
Paper wasp image credit: Mike Keeling
License info: CC BY-ND 2.0

As you go through the key, different groups are eliminated. If you’d like to key out the wasps above, this is the key used by most researchers to identify wasps in most of the US. The potter wasp image can be found here, and the paper wasp image can be found here.

If you were to take the time to key out the wasps above, you’ll notice something very odd about the wasp on the left. There’s no place in the key where the wasp fits. The proper section of the key (here) directs you to a pair of wasps which do not look like the wasp in the picture above.

Why is that? Why doesn’t it fit?

The wasp above is a species which isn’t found in the US, while the key is meant for wasps which are found in the US. The wasp on the left is a Delta potter wasp, which is found in Africa and Asia. The key isn’t meant to ID this group, so it’s left out.

In other words, the wasp ‘breaks’ the key. However, the wasp still has a name…which means it’s known to science. So if you were to find this wasp in the US, how would it get identified?

Specialist

Soybean plataspids feeding on Kudzu.
Image Credit: University of Georgia.
License info: CC-BY-NC-2.0

The example of the wasp above isn’t very farfetched. In fact, it’s happened before. In 2009, a student at the University of Georgia captured an odd insect in a Kudzu patch. The insect didn’t fit into the keys he was using to ID the insect, keys which are known to cover most insects found in the US.

The insect was sent to an insect museum, where it was looked at by a person who specializes in insect identification. The insect was found to be a type of insect which hadn’t been recorded from the United States, the Soybean Plataspid. This insect is now found across one quarter of the US, making it the fastest recorded biological invasion ever recorded.

We’ve talked about why collections are important, but the people who maintain these collections are just as important. These specialists are called taxonomists, and they specialize in identifying and organizing the species which may or may not be new. Each specimen is important because it tells us something about the bugs around us.

Unfortunately, taxonomy is underfunded and this has held back many areas of science because classifications are not updated as fast as other data comes out. Interested readers can read more about this problem here, or read Morgan Jackson’s ballpark estimate of how much it costs to describe a new species.

Sometimes, we’re not actually sure if what we’re looking at is new.

This is a scuttle fly, and that’s pretty much all I’ll probably ever be able to tell you about it.
Photo credit: John Tan, via Flikr.
Image license: CC-BY-2.0

There’s a joke in the world of bug scientists: the biggest group of moths is LBMidae, which stands for Little Brown Mothidae. There’s a lot of little brown moths which can be really hard to tell apart from one another. If you can’t tell what group the moth belongs to, there’s no way to know whether it’s new.

Most of the bugs people are familiar with are big or pretty. Butterflies, beetles, dragonflies,and some groups of wasps are popular because people can see them without a microscope. However most insects are small, brown and really hard to ID.

People tend not to look at the groups which are hard to ID, which means that there’s a lot of bugs that nobody’s seen before. In fact, a bunch of scientists went into Los Angeles and described over 30 new species from the backyards of heavily populated urban areas. Scientists have even discovered new species on college campuses, species which had been overlooked for years despite a healthy population of entomologists.

The Bottom Line

Telling which bug is what can be really hard, but there are ways to know what bugs are what. With a lot of experience, you can tell different bugs aparts as well as you can tell different breeds apart.

There are online tools to help you ID bugs, and we’re almost willing to look at bugs for people. If we don’t know what they are, we’re happy to connect them to someone who likely does.

A special thanks to Stephane De Greef for letting use his Delta image for this post. He can be found on Facebook here.