Is It a Caterpillar? How to Tell Caterpillars From Look-Alikes

• Relationship to adults: complete metamorphosis passes through egg, larva (the caterpillar), pupa, and adult; the larva molts several times before pupating, forming either a chrysalis or a cocoon.
• Distinguishing from beetle larvae (grubs): beetle larvae, such as leaf beetle larvae, have no prolegs but do have true legs.
• Distinguishing from fly larvae (maggots): fly larvae lack true legs entirely and have only fleshy protuberances on the abdomen or on both the abdomen and thorax.
• Distinguishing from sawfly larvae (not one of this set's groups, but similar in appearance to caterpillars): sawfly larvae have prolegs on six or more abdominal segments, more than the five or fewer found on caterpillars.

People most often mix caterpillars up with:

• Grubs
• Maggots

Open the other page and compare its list against the marks above; the differences are usually in the antennae, wings or the way the body is divided.

Not all caterpillars sting, but some species (flannel moth/puss moth caterpillars) have venomous hairs or spines that cause intense pain and even systemic symptoms on contact; other species (such as the hickory tussock moth caterpillar) cause only localized rash and itching rather than a true sting. Seek medical care promptly for severe symptoms or any allergic reaction.

Feeding on foliage can kill or stunt the growth of young plants; caterpillars are a common pest of garden and landscape plants.

Mostly found on host plants or in the soil near them; garden flowers are especially susceptible to damage.

Get as close as your camera will focus, from directly above, in daylight or a bright lamp. Include the whole body with the legs and antennae in frame; a second shot from the side shows wings and body segments. Put a coin or ruler next to it for scale. For a bite or a bug found on skin or bedding, photograph the bug itself, not the mark. The app names the likely group; use the list above to confirm.