THE INSECT ORDERS
Stag BeetleThe concept of "insect orders" is important for us backyard naturalists because all the world's many thousands of insect species can be pigeon-holed in them, and there is such a small number of orders -- maybe 25 to 35, depending on your expert -- that our brains can deal with that number. In other words, a good first step in mastering insect diversity is learning to assign any insect we find anyplace in the world to one of the orders.

For us backyard naturalists, this challenge is even easier than it seems. That's because about half of the orders are very small ones seldom encountered, or else species included in them appear only in habitats unlikely to occur in backyards. The vast majority of conspicuous insects backyard naturalists are likely to see and identify belong to one of just ten orders -- the "Big Ten." The Big Ten is just a grouping I've always used to help myself keep the orders straight -- it has no scientific status at all.

What follows is a list of insect orders as defined in a popular insect field guide. In the following list, my "Big Ten" are highlighted in red.

THE INSECT ORDERS
according to a popular field guide

  1. ORTHOPTERA: grasshoppers, crickets
  2. COLEOPTERA: beetles
  3. LEPIDOPTERA: butterflies, moths
  4. DIPTERA: flies, mosquitoes
  5. HYMENOPTERA: ants, wasps, bees
  6. HEMIPTERA: true bugs
  7. HOMOPTERA: aphids, cicadas
  8. DERMAPTERA: earwigs
  9. ODONATA: dragonflies
  10. ISOPTERA: termites
  1. THYSANOPTERA: thrips
  2. NEUROPTERA: ant lions
  3. COLLEMBOLA: springtails
  4. PROTURA: proturans
  5. DIPLURA: diplurans
  6. THYSANURA: bristletails
  7. EPHEMERIDA: mayflies
  8. PLECOPTERA: stoneflies
  9. EMBIOPTERA: webspinners
  10. PSOCOPTERA: booklice
  11. ZORAPTERA: zorapterans
  12. MALLOPHAGA: chewing lice
  13. ANOPLURA: sucking lice
  14. STREPSIPTERA: twisted-winged parasites
  15. MECOPTERA: scorpionflies
  16. TRICOPTERA: caddisflies
  17. SIPHONAPTERA: fleas

A MORE RECENT CONCEPT OF THE SUBDIVISIONS OF
CLASS INSECTA

Nowadays with gene sequencing providing new insights into how living things are related, many traditional concepts are changing, including among the insects. The following is a list of insect orders according to the NCBI Taxonomy Database, as of September, 2010. Note how there are newly recognized orders such as the "Heelwalker Order" plus nowadays cockroaches, mantids and more have their own orders.  Probably these concepts will change more. To see current concepts, go to the NCBI page for the Class Insecta

  1. SUBCLASS/Order: Archaeognatha (bristletails)
  1. SUBCLASS/Order: Thysanura (silverfish and firebrats)
  1. SUBCLASS: Palaeoptera
  • Order Ephemeroptera (mayflies)
  • Order Odonata (dragonflies, damselflies)
  1. SUBCLASS Neoptera
  • Order Embioptera (web-spinners)
  • Order Lepidoptera (butterflies, moths)
  • Order Trichoptera (caddisflies)
  • Order Coleoptera (beetles)
  • Order Diptera (flies)
  • Order Hymenoptera (wasps, bees, ants... )
  • Order Mecoptera (scorpionflies)
  • Order Megaloptera (dobsonflies... )
  • Order Neuroptera (antlions, lacewings... )
  • Order Raphidioptera (snakeflies)
  • Order Siphonaptera (fleas)
  • Order Strepsiptera (twisted-wing parasites)
  • Order Dermaptera (earwigs)
  • Order Blattaria (cockroaches)
  • Order Isoptera (termites)
  • Order Mantodea (mantids)
  • Order Grylloblattodea (rock crawlers, icebugs)
  • Order Mantophasmatodea (heelwalkers)
  • Order Orthoptera (grasshoppers, crickets)
  • Order Phasmatodea (walking sticks)
  • Order Hemiptera (true bugs)
  • Orter Phthiraptera (lice)
  • Order Psocoptera (booklice, barklice)
  • Order Thysanoptera (thrips)
  • Order Plecoptera (stoneflies)
  1. UNCERTAIN POSITION
  • Order Zoraptera (angel insects)

Looking over the above list, it's easy to see why so many people "get hooked" on insects. It's simply because insects have so many strange manners of being. When you begin paying attention to insects, it's like going to another world where you find beings totally different from anything you've ever known, or even thought of. Even more mind-expanding is the fact that always, once you've studied what seems to be the insects' weirdness, their cruelty, or even their profound stupidity, you come to see that their manner of being is actually an exquisite adaptation to the ecological niche they occupy.

If you'd like to review some insect field guides available online at Amazon.com, you might take a look at the Golden Nature Guide called Insects : A Guide to Familiar American Insects; The Audubon Society's "First Field Guide" for beginners, called Insects; Audubon's "Pocket Guide" called Familiar Insects and Spiders North America, and; the Peterson Field Guide A Field Guide to Insects: America North of Mexico.

A good way to begin the insect-learning process is to print up our "Key  to the Big Ten Insect Orders," go outside with your hand lens, and see if you can assign some insects to their orders.