Bug Identifier

True Bugs

Squash Bug

Anasa tristis

048121620
Body length in millimeters. Shaded bar shows the typical adult range.
Scientific nameAnasa tristis
GroupTrue Bugs
Size14–16 mm (up to about 0.63 in)
Colors Brown and Gray
Legs6 legs
WingsYes
Where foundGarden or plants
Most activeSummer
BitesNo
StingsNo
Risk levelNuisance

How to identify it

The squash bug is a medium-sized member of the true bugs group. Piercing, straw-like beaks and wings that overlap in an X on the back. Check for these three features:

  1. Flattened, dull gray-brown body
  2. Orange and brown striped abdomen edges
  3. Bronze egg clusters in a diamond pattern under leaves

About this bug

A flat, grayish-brown bug that sucks sap from squash and pumpkin vines, causing leaves to wilt and turn crispy. Clusters of bronze eggs appear on leaf undersides.

You'll usually find squash bugs in gardens and on plants. They are most active in summer.

Is it dangerous?

Squash bugs don't harm people; they can wipe out squash and pumpkin plants.

Our rating: Nuisance, meaning it is a nuisance pest but not a health threat to most people.

When you'll see squash bugs

Squash Bugs are most active in summer. Summer heat speeds up development, so populations can grow quickly.

Typical places to check: garden or plants.

About true bugs

The squash bug is one of the true bugs. True bugs have piercing, straw-like mouthparts used to suck plant sap or, in a few species, blood. They develop through gradual metamorphosis: nymphs look like small, wingless adults and molt several times as they grow. Many release strong odors from scent glands when threatened.

Because nymphs look like adults, you'll often see mixed sizes of the same bug together, which is a good sign that a population is breeding nearby.

What to do about it

  1. Scrape egg clusters off leaves every few days
  2. Lay a board near plants overnight and destroy the bugs underneath in the morning
  3. Use row covers until flowering and clean up vines in fall

Read the full guide: how to get rid of squash bugs.

Bugs that look similar

Brown Marmorated Stink BugHalyomorpha halys12–17 mmNuisance

Where found: look for squash bugs in gardens and on plants; brown marmorated stink bugs turn up indoors and in gardens and on plants.

Western Conifer Seed BugLeptoglossus occidentalis16–20 mmNuisance

Size: Western Conifer Seed Bugs are larger, reaching 20 mm, while squash bugs top out around 16 mm.

Frequently asked questions

What does a squash bug look like?

Flattened, dull gray-brown body. Adults measure 14–16 mm (up to about 0.63 in).

Does the squash bug bite or sting?

It does not bite. It does not sting. Squash bugs don't harm people; they can wipe out squash and pumpkin plants.

Where do squash bugs live?

Squash Bugs live in gardens and on plants.

When are squash bugs most active?

Mostly in summer.