When I encounter a new insect in my backyard, I want to know what it’s likely to do while it’s here. Is it going to eat one of my garden plants? Is it a good pollinator for my flowers? Will it lay eggs in the soil, or pupate somewhere? I can learn some things about an insect just by observing it for a while, of course, but that’s not always practical. A good field guide or website may provide information about the mysterious visitor, but I need to know what it is first.
So how do you identify an insect you have never seen before? You collect as much information as you can, looking for clues that will place the insect in a taxonomic order. Ask yourself each of the following questions about your unidentified insect. You might not be able to answer all of them, but any information you gather will help narrow down the possibilities.
First, be sure you are looking at an insect, and not another arthropod cousin. Does it have six legs? Are there three distinct body regions – head, thorax, and abdomen? Do you see a pair of antennae? Most, but not all, insects have two pairs of wings.
You can learn more about basic insect anatomy by reading What Are Insects?
Illustration credit: CorpsWeb (US Army Corps of Engineers), modified by Debbie Hadley