Insect Classification Lesson {plus a printable!}

Insects are fascinating creatures. They are everywhere and there are a lot of them! One million species of insects have been identified and there are thought to be another 5-6 million species waiting to be discovered. That makes insects the largest class of animals on Earth.

Found in nearly every ecosystem on Earth, with the exception of the poles, insects can thrive in conditions other animals cannot.  While some of us might think they are creepy, the truth is they are essential to the ecosystems they inhabit and many insects are very beneficial to humans.

Characteristics Of Insects

Insects are found in many different environments. They come in many shapes, sizes, and colors. However, all insects share several defining characteristics that set them apart from other animals. All insects have:

• 3 pair of legs
• an exoskeleton
• usually have wings at some stage in life
• antennae
• 3 body segments: head, thorax, and abdomen
• life cycle involves metamorphosis (either complete or incomplete)

Related post: Insect Printable Worksheet

Insect Classification

Scientists have worked hard to attempt to identify all living things. They are not done yet. Almost daily, new species of plants, animal, fungus, or bacteria are discovered. Scientists have taken all the identified species on Earth and have sorted them into groups based on similar characteristics. These groups are broken down into yet smaller groups.

Dividing things into smaller, similar groups is called classification. The science of dividing, or classifying, living things is called taxonomy. The taxonomic insect classification is: Kingdom Animalia, Phylum Arthropoda, and Order Insecta.

The Class Insecta can be further divided into 29-32 Orders depending upon the classification system used. Species in each order share unique characteristics that set them apart from other insects, yet have the same traits that all insects share. Let’s outline a few of the more common orders containing familiar insects.

Coleptera (beetles)

• largest order of any animal with approximately 370,000 known species
• make up 25% of all known plants and animals
• found in every ecosystem except salt water and polar ice caps
• exoskeleton is very hard
• have biting mouthparts
• 2 pairs of wings, one for flying and one for a protective covering
• larvae are considered “grubs”
• life cycle – complete metamorphosis (egg, larva, pupa, adult)

Lepidoptera (butterflies and moths)

• second largest animal order with over 160,000 known species
• have large wings covered in tiny scales
• wings are often brilliantly colored or patterened
• adults feed on nectar gathered by a long tube that extends from their mouths called a probiscus
• “taste” with their feet
• life cycle – complete metamorphosis (egg, larva, pupa, adult)
• differences between butterflies and moths

Hymenoptera (ants, bees, and wasps)

• 2 pair of wings
• bees visit flowers to collect pollen and nectar
• may have chewing mouthparts or tubes to collect nectar from flowers
• can smell with their antennae
• wasps visit flowers to prey on smaller insects (often pests)
• well developed compound eyes
• can be social or solitary
• social species have a highly developed social structure
• life cycle – complete metamorphosis (egg, larva, pupa, adult)

Diptera (flies, gnats, mosquitoes)

• 2 pair of wings
• forewings are used for flight and hindwings are used for balance
• well developed compound eyes
• mouthparts designed to suck or pierce, not bite
• feed on liquids
• life cycle – complete metamorphosis (egg, larva, pupa, adult)
• considered pests and some are disease carriers

Orthoptera (grasshoppers and crickets)

• well developed mandibles and can bite
• 2 pair of wings – hindwings for flight and forewings are leathery wing protectors
• large hind legs allow them to jump
• can “sing” or “chirp” by rubbing parts of their bodies together
• life cycle – incomplete metamorphosis (egg, nymph, adult)
• grasshoppers eat plants, crickets hunt smaller insects

Hemiptera (“true bugs”, cicadas, aphids)

• piercing mouthparts to suck juice from plants or animals
• some species have 2 pair of wings, some have 1 pair, and others have no wings
• life cycle – incomplete metamorphosis (egg, nymph, adult)
• considered agricultural pests

Odonata (dragonflies and damselflies)

• relatively large insects with long bodies
• 2 pair of similarly sized wings that are transparent and veined
• large heads and large compound eyes
• very small antennae
• life cycle – incomplete metamorphosis (egg, nymph, adult)
• adults eat smaller insects

Insect Order Printable

Use the above information regarding the most common insect orders with your students with this handy insect order printable. Just fill out the form below and it will be emailed to you.

Insect Collection

This lesson will come in handy if you are doing an insect collection.

To Learn About The Other Insect Orders

If you would like to learn about the other insect Orders, here are a few helpful links.

• Amateur Entomologists’ Society
• DiscoverLife.org
• BugGuide.net

What are your favorite insects? What Order are they found in?