MSU Extension Gardening in Michigan

Meet the Neighbors! Common Insect Groups

More than a million insect species have been discovered on Earth and divided into commonly understood scientific categories. Scientists estimate there are 5 million to 10 million more insect species still to discover!

Scientists use a system called taxonomy for dividing living things into groups or categories. In basic taxonomy, the smallest group of closely related individuals is called a species, and the groups get bigger from there: genus, family, order, class, phylum, and kingdom. For example, the taxonomic species name for the insect that gardeners may know as the common eastern bumble bee is Bombus impatiens. Its genus is Bombus. (The species name always  starts  with  the  genus name.) Bombus impatiens belongs to the family Apidae, order Hymenoptera, class Insecta, phylum Arthropoda, and kingdom Animalia.

There are about 30 orders in the taxonomic class Insecta, depending on which taxonomist is doing the classifying. The number of orders has changed over time and will likely continue to as new DNA evidence shows that groups that look alike aren’t as closely related as scientists once believed.

Some orders are highly specialized, such as the ice crawlers (order Grylloblattodea) that only live in caves or under glaciers. Others, like Coleoptera, the beetles, include tens of thousands of species that live in aquatic or terrestrial habitats.

This lesson will introduce you to five insect orders (see the table) that are common in Michigan: Coleoptera, Hemiptera, Hymenoptera, Odonata, and Orthoptera.

Five orders of the class Insecta that are common in Michigan, along with the most common members of the order and their mouthpart and metamorphosis types.

COLEOPTERA

With more than 400,000 named species, Coleoptera (beetles) is the largest insect order, and about 4,300 of them are found in Michigan.

All beetles have hard abdomens, called elytra (singular, elytron). The elytra are modified forewings that cover and protect the hind wings. All adult beetles have chewing mouthparts, but they feed on a variety of food sources. They may be predators, herbivores, fungus- feeders, or omnivores. Beetles include some of the best-known garden pests in Michigan  such  as the Japanese beetle, lily leaf beetle, and viburnum leaf beetle.

Beetle larvae have many different body types (Photo 2-1). You can find beetles in or on plants and wood, in the soil, or just walking around. Some beetles live most of their lives underground as grubs, the larval life stage, feeding on  soil roots. Other beetle larvae are aquatic or may look like maggots and not move much. Lady beetle larvae (Photo 2-2) are black and orange, hang out on plant foliage, and feed on soft-bodied insects like aphids.

HEMIPTERA

Species in this order, sometimes called the true bugs, are named for the characteristics on different sections of each wing. The wings are membranous and clear toward the end of the abdomen, while their forewings are hard and leathery in the section closest to the thorax (Photo 2-3). Hemipteran adults are highly mobile and large numbers of them can gather on a single plant. True bugs have only four or five segments on their antennae and come in a variety of sizes and colors. Many that feed on plants rely on their green coloration to hide them from the other insects, birds, and animals that would like to eat them.

The mouthparts of Hemiptera are modified into a straw-like appendage for ingesting food by piercing- sucking. The order Hemiptera includes major garden pests like aphids, leafhoppers, and four lined plant bugs. Some Hemiptera pest species like leafhoppers and aphids carry viruses on their mouthparts that they transmit from plant to plant when feeding.

Hemiptera also includes beneficial insects, such as predatory stink bugs and damsel bugs (the subject of Lesson 3) that feed on eggs and larvae.

Hemiptera also includes intriguing insects like cicadas, whose loud, attention-getting mating calls and fascinating life cycles make them frequent subjects of summertime news articles. Depending on the species, cicadas spend anywhere from 2 to 3 years (annual cicadas) up to 17 years (periodical cicadas) underground.

HYMENOPTERA

The defensive tactics of the ants, bees, and wasps that make up the order Hymenoptera are not always popular with humans, but we benefit from many of them anyway. For example, bees are some of nature’s best pollinators. As they fly from plant to plant, seeking nectar and pollen, they pollinate fruits and vegetables for us to eat, and flowers for us to enjoy. Visit the Native Bee Habitat page on MSU’s Michigan Pollinator Initiative site for advice on attracting bees to your backyard.

Outdoor ants may be merely a nuisance (sugar ants, pavement ants) or a genuine threat to your home’s structure (we’re looking at you, carpenter ants!) when they’re indoors. But outdoor ants are experts at cleaning up seeds, dead or living insects, and other organic matter outdoors. Learn about some common ants you may meet on Cornell University’s What’s Bugging You? Ants web page.

Wasps are the largest group in the order Hymenoptera, with nearly 100,000 species globally and about 17,500 in the U.S. You may be most familiar with one of the social wasp species such as bald-faced hornets or yellow jackets, which humans are most likely to tangle with in the late summer and fall.

Though the nests of social wasps often have hundreds of worker wasps, most wasp species are solitary. Each species  preys  on  a single type of insect and they typically aren’t a threat to people.

You probably never notice the most common types of wasps because they’re so small. Parasitoid insects are a unique group that lay their eggs in or on other insect eggs, larvae, or pupae. When the parasitoid eggs hatch, they eat the host organisms. Though most parasitoids are wasps, some flies are also parasitoids.

Sawfly adults look like wasps but lack the narrow space between the abdomen and thorax that is characteristic of wasps (Photo 2-4). Sawfly larvae look like caterpillars and chew on the leaves of trees and shrubs. You can tell sawfly caterpillars apart from butterfly and moth caterpillars by the number of prolegs (false legs) on the abdomens. Sawfly caterpillars have six or more prolegs, while caterpillars have fewer.

All Hymenopterans undergo complete metamorphosis. Their larvae don’t move much and stay in the nest until they turn into pupae.

ODONATA

The order Odonata is made up of dragonflies and damselflies. About 170 species of Odonata are found in Michigan. These insects have large eyes, very short antennae, and complex patterns of veins on their wings. The wings of adult damselflies rest over the abdomen and are narrower at the base than the wings of adult dragonflies, which rest perpendicular to the abdomen.

Adult dragonflies and damselflies live on land and feed on flying insects like mosquitoes. They lay their eggs one by one in water, where the larvae live after hatching. The larvae prey on smaller aquatic insects.

ORTHOPTERA

“Insects that jump” is a good basic description for the order Orthoptera. Adult grasshoppers, katydids, and crickets all have large hind legs they use for jumping and thickened forewings they use to fly. Michigan has close to 140 species in this group of good jumpers.

One way to tell these jumpers apart is by their antennae. Katydids have antennae that are almost as long as their bodies. Grasshoppers have short antennae. Cricket antennae are between the other two in length. Crickets also have two appendages called cerci that stick out from the back of their abdomens (Photo 2-5).

Orthoptera undergo simple metamorphosis. Immature insects in this order closely resemble adults but lack wings. All Orthoptera species have chewing mouthparts and feed on plant foliage. They rarely gather in sufficient numbers to become plant pests in Michigan, so you can ignore them in your garden and yard.

Crickets and katydids are well- known for their ability to produce noise by rubbing two body parts together (called stridulation). Crickets rub two of their wings together to produce sounds, which vary among species.

Grasshoppers, katydids, and crickets are relatively large insects, so their main  insect predators are  a small group of predatory wasps that feed the Orthoptera to their offspring.

WHAT’S NEXT?

Some orders in class Insecta are common (for example, Lepidoptera, or butterflies) and others (like Phasmatodea, or stick insects, or Psocoptera, called barklice), are found only under very specific conditions. Lessons 3, 4, and 5 will profile several beneficial insects and explain the important roles they play. Next up: An underground predator, the Scarites beetle.

FIND OUT MORE: REFERENCES & RESOURCES

The print and online resources in this list delve deeper into insect development and behavior.

Cornell Integrated Pest Management. (n.d.) What’s bugging you? Ants. https://cals.cornell.edu/integrated-pest-management/ outreach-education/whats-bugging-you/ants

Cranshaw, W., & Shetlar, D. (2017). Garden insects of North Amer- ica: The ultimate guide to backyard bugs (2nd ed.). Princeton University Press.

Lowenstein, D. (2021). Michigan insects in the garden—Season 2 week 1: Annual cicadas (MSU Extension News Article). https:// www.canr.msu.edu/news/michigan-insects-in-the-garden- season-2-week-1-annual-cicadas

Lowenstein, D. (2023). Lily leaf beetles continue to spread in Mich- igan (MSU Extension News Article). https://www.canr.msu.edu/ news/lily_leaf_beetle_watch_out_for_this_garden_pest

Lowenstein, D. (2025). What’s eating my viburnums and how can I stop it? (MSU Extension News Article). https://www.canr.msu.edu/ news/keep_your_eyes_open_for_the_viburnum_leaf_beetles

Mercer, N. (2020). Insect parasitoids: Important natural ene- mies of pests. University of Kentucky; College of Agriculture, Food, and Environment; Cooperative Extension Service. https://entomology.ca.uky.edu/018

Michigan Pollinator Initiative. (n.d.). Native bee habitat. Michigan State University. https://pollinators.msu.edu/resources/pollinator-planting/native-bee-habitat/ 

North Carolina State University Agriculture and Life Sciences. (2015). Bug bytes. https://genent.cals.ncsu.edu/bug-bytes/

Raupp, M. (n.d.). Bug of the week. https://bugoftheweek.com/ Singing Insects of North America. (n.d.). Sample songs of crickets and katydids [Sound samples]. https://orthsoc.org/sina/ a00samples.htm

Smitley, D., & Davis, T. (2017). Japanese beetle: Tips for your lawn [Fact sheet]. Michigan State University Extension. https://www. canr.msu.edu/resources/japanese_beetle_tips_for_your_lawn