What Kind of Bug Is This? Common Bug Groups

Is It a Aphid? How to Tell Aphids From Look-Alikes

Aphids: 4 marks to check, what they are often confused with, whether they bite or sting, and where they turn up, quoted from university entomology and IPM sources.

These pages help you narrow a bug down to its group from what you can see. They are not medical advice. Seek medical care promptly for severe symptoms or any sign of an allergic reaction.

Download on the App Store

At a glance

Body plan: Aphids are oblong to pear-shaped, soft-bodied insects with long legs and antennae; they have tubular sucking mouthparts, and most species bear a pair of tubelike cornicles projecting from the rear of the abdomen; winged and wingless forms occur.
Size: Body length about 1/25 to 1/12 inch (1-2 mm) at maturity.
Bites or stings: Not covered by the sources we opened; handle unknown bugs with care.
Where you find them: Found outdoors on host plants; almost any plant can host one or more aphid species.

How to tell it is one of the aphids

Most aphid species have a pair of tubelike cornicles ("tailpipes") projecting backward from the top of the abdomen.
Aphids have soft, pear-shaped bodies with long legs and antennae.
Antennae posture differs between look-alike species: green peach aphid antennae extend beyond the body, while melon aphid antennae folded back reach only to the middle of the abdomen.
Aphids may be winged or wingless depending on colony crowding; winged forms appear only when a plant becomes heavily infested.

Often confused with

People most often mix aphids up with:

True bugs

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.

Pest or beneficial?

Aphids are plant pests that curl leaves and excrete sticky honeydew attracting ants and sooty mold, and can transmit plant viruses (melon aphid vectors at least 44 viruses, green peach aphid more than 100). They also have many natural predators and parasites.

Where they turn up

Found outdoors on host plants; almost any plant can host one or more aphid species.

How to photograph it for identification

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.

FAQ

Do aphids bite or sting?

The sources we opened for this group do not describe bites or stings. Treat any bug you cannot identify with care and avoid handling it bare-handed.

What is the quickest way to recognize aphids?

Most aphid species have a pair of tubelike cornicles ("tailpipes") projecting backward from the top of the abdomen.

Are aphids a pest?

How do I tell aphids from true bugs?

Antennae posture differs between look-alike species: green peach aphid antennae extend beyond the body, while melon aphid antennae folded back reach only to the middle of the abdomen. The True bugs page lists its own marks.

See what's really crawling, flying, and buzzing past.

Start with a single photo.