Just as music stores divide CDs into “Rock,” “Pop,” “Rap” and other styles, the animal kingdom is divided into several groups called phyla.
(Kingdom > Phylum > Class > Order > Family > Genus > Species)
For example: You and every other animal with a backbone belong to the phylum Chordata.
The phylum that contains insects is called Arthropoda, and it has a number of classes. These include:
Crustacea
(crabs, crawfish, shrimp...the "delicious" class of arthropods) |
Arachnida
(spiders, mites, scorpions) |
Myriapoda
(millipedes & centipedes) |
Insecta
(insects) |
The class Insecta is divided into into 29 orders including:
- Mantodea - praying mantids
- Blattodea – cockroaches
- Isoptera – termites
- Siphonaptera – fleas
- Odonata - dragonflies and damselflies
- Dermaptera – earwigs (But don’t let the name fool you! They are not really “wigs.”)
- Diptera – flies
- Lepidoptera - butterflies and moths
- Orthoptera - grasshoppers, katydids, crickets
- Coleoptera – beetles
- Hymenoptera - wasps, bees, ants, sawflies
What makes an insect an insect?
There isn't a typical body plan for most insects since there are so many exceptions, but, in general, there are some very common features:
- The insect body is divided into three main parts: the head, thorax and abdomen.
- Insects have no internal skeleton, instead they are covered in an external shell (exoskeleton) that protects their internal organs.
- Insects have one pair of antennae located on the head.
They've been around a long, long time.
Insects are an ancient group of animals that first appeared before the Devonian period (400-360 million years ago)  and had begun flying by the Carboniferous period (360-285 million years ago).
Flight was a pretty good move for insects, and during the Permian period (285-245 million years ago), insects peaked in population and diversity.
Hymenoptera (ants, bees, wasps and sawflies) and Lepidoptera (butterflies and moths) appeared as fossils in the Jurassic period (210-145 million years ago).
Some ancient insects looked similar to ones we have today. It’s believed that prehistoric dragonflies had a wing span of up to three feet.
Insects have been around much longer than humans, and they outnumber us 1.5 billion to one.
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