JUNE
2012

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

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Check out these books by Tom Turpin:

Flies in the face of fashion

What's Buggin You Now?

 

 

 

06-28-12

Download the audio of On Six Legs: MP3, WMV

Misidentification of Insects a Common Occurrence


In general, the first question that most people ask when they see an insect is, "What is it?" This question warms the cockles of the hearts of insect taxonomists - scientists who define groups of insects and give names to new species. Taxonomists love to put names on things.

Several hundred thousand species of insects have been described, so identifying an insect is not always an easy task. Scientists use what are called taxonomic keys to aid insect identification. Such keys feature questions about characteristics of the insect in a yes-or-no format. For example: Wings present?

Some insect identification keys are designed so they can also be used to determine an insect to its species. Such keys are generally difficult for nonscientists to use. Other keys, though, are constructed with the general public in mind. These so-called field guides - often with photos - deal with the most common insect species.

Based on my observations, the first question from a person who wants to know the name of an insect is followed quickly with a second, more practical, inquiry: "Is it dangerous?" To most people, the actual name of an insect is not as important as is the potential to be harmful.

Of course, some general insect names are associated with undesirable attributes. Bees and wasps bring the risk of a sting, mosquitoes can bite and cockroaches elicit the revulsion associated with finding one in the house. So insects with such names are automatically assumed to be bad.

To make matters of identification difficult, some insects structurally and behaviorally mimic other insects to gain protection. For instance, some flies look very much like honey bees. This provides a level of protection to the flies, because of the general respect afforded bees.

Back in ancient history, the honey bee and a species of drone fly were confused in what today is known as the Bugonia Myth. In days gone by, people believed that honey bees originated by spontaneous generation from the carcass of an ox. An understandable error, because a drone fly mimic of honey bees would be seen flying around the dead animal.

That myth is preserved for us today in the scientific name of the honey bee - Apis mellifera. Apis was the bull god of Egyptian mythology. Linnaeus, the scientist known as the father of taxonomy, gave the scientific name to the honey bee. He chose the name Apis as the generic name in recognition of the incorrect theory of how the insect developed.

drone fly
Drone fly

Ancient people haven't been the only humans to confuse the identity of bees and flies. Several years ago, I helped construct a word problem for an elementary math textbook. The problem involved how many trips a honey bee would have to make to produce a given quantity of honey. To my surprise, when the textbook was published, that problem was illustrated with a picture labeled as a honey bee. The picture was a drone fly! 

dragonfly
Dragonfly

A lot of of insects look enough alike so that it is easy to confuse which is which. For instance, a couple of months ago I received a gift bottle of wine. It was a dry white table wine, labeled Dragonfly. The choice of the name was appropriate, because according to the label, "On the pond in front of our tasting room dragonflies flourish during the summer months." One minor problem: the picture on the label featured a damselfly, not a dragonfly.

Damselfly
Damselfly

Dragonflies and damselflies do resemble each other. Both have a long narrow body. Both have four cellophane-like wings. Both live in the water as immatures. Both are aerial predators, feeding on flying insects they capture while on the wing. Both are classified in the insect order Odonata. But they are different types of insects. How do you tell? The most obvious way is that dragonflies are stouter in build and hold their wings out to their sides when at rest. Damselflies fold their wings when at rest.

With all the insects in the world, many species do look somewhat alike. Some insects benefit from the charade, but it can be a bit confusing to most of us, especially editors of textbooks and bottlers of wine.

 

Writer: Tom Turpin
Editor: Olivia Maddox