Naturalists Notebook

The Eight Most Common Orders of Insects

You’ve found a strange new insect. You reach for your field manual on insects. Where do you begin to search? With the phenomenal diversity of species in the insect world, this can be a challenging exercise in page flipping. Luckily, about 90% of the insects you are likely to encounter will fall within 8 broad divisions known as Orders. Field guides may contain as many as 25 or more orders. The 8 largest orders are listed below with the common insects that belong to them and their main characteristics. Now all you have to do is remember the names of the orders and the outstanding characteristics of each and you will be ready to command any field guide.

When I was much younger (in junior high, I believe), my science teacher provided us with a mnemonic for remembering the levels of scientific classification. It went like this: King Pluto Came Out For Green Spinach. This virtually meaningless sentence has enabled me to remember Kingdom, Phylum, Class, Order, Family, Genera and Species all these long years. Now what we need is a mnemonic for the major orders of insects. Something like:

‘High Dollar Harry’ Helps Odd Orthoptera Live Comfortably.

or maybe

Ornery ‘Hot Headed Henry’ Deliberated Over Lost Cool.

what about this

Come On Out Herbert, Help Hannah Lift Dad.

Please, stop me.

Anyway, pick one or invent your own.

Hymenoptera (ants and bees)

Scientific name means "membrane wings".

Characteristics include: Two pairs of thin, clear, membranous wings; hindwing is smaller. In the females, the abdomen ends in a well-developed egg-laying organ and/or stinger. The only insects with ‘stingers’. Often social or colonial.

Diptera (flies, mosquitoes, gnats, punkies)

Scientific name means "two wings".

Characteristics include: One pair of wings. This is the overwhelming fact to remember. Some flies look like bees or wasps but can be easily distinguished by noting the presence of 2 or 4 wings. The eyes are large and the antennae are small. Many flies are very small such as gnats or punkies.

Lepidoptera (moths, butterflies)

Scientific name means "scaly wings".

Characteristics include: Two pairs of wings covered with small scales that rub off easily. Usually with prominent antennae that is knob-like or feathery. Sucking mouth parts.

Coleoptera (beetles)

Scientific name means "sheath wings".

Characteristics include: Pair of hardened wings covering the top of the body and meeting in a straight line down the back. Beetles have two pairs of wings, but the membranous pair is usually not seen because they are covered by the wing sheaths whenever the insect is at rest. Chewing mouth parts.

Orthoptera (crickets, grasshoppers, locusts, roaches, walkingsticks)

Scientific name means "straight wings".

Characteristics include: Usually have long back legs, hop high in the air, and often make rhythmic sounds. This group also includes the praying mantis and the cockroach. What they all have in common are thin, leathery forewings that cover larger hind wings that are folded like a fan when at rest. One exception to this rule are the walkingsticks which have no wings.

Odonata (dragonflies, damselflies)

Scientific name means "tooth".

Characteristics include: Two pairs of long, narrow, membranous wings that are roughly equal in size. They also have large eyes and extremely long, narrow abdomens. Antennae are short.

Homoptera (aphids, cicadas, leafhoppers, scale insects)

Scientific name means "same wings".

Characteristics include: Two pairs of membranous wings that are held in a tent-like or rooftop position over the body when at rest. They have jointed beaks designed for sucking plant juices. Beak is connected to base (underside) of head. This order also includes scale insects that are often found attached to plants and have reduced or undeveloped body parts.

Hemiptera (Bugs, backswimmers, water striders)

Scientific name means "half-wings".

Characteristics include: Triangle on the back just behind the head. This is formed by the way the insects fold their forewings when at rest. Hemiptera have two pairs of wings: The hind wings are all membranous, while the forewings are partly thickened. Some bugs look similar to beetles, but you can distinguish them by seeing the wings form a triangle on the back instead of meeting in a straight line. Jointed beak for sucking is connected to the front part of the head.

Reference:

Borrer, Donald J. & White, Richard E. A Field Guide to Insects. Boston, Massachusetts: Houghton Mifflin Co., 1970.

Jaques, H. E. How to Know the Insects. Dubuque, Iowa: Wm. C. Brown Company Publishers, 1947.

Milne, Lorus and Margery. The Audubon Society Field Guide to North American Insects and Spiders. New York: Alfred A. Knopf, inc., 1980. p.512

Stokes, Donald W.. A Guide to Observing Insect Lives. Boston, Mass: Little, Brown & Company ltd., 1983. pp.215-218

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Royce & LuCretia Milam Copyright © July 1996 Wild Vision. All rights reserved.