What Do Squash Bugs Eat? A Friendly Guide to Their Diet

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Squash bugs can be a real nuisance in your garden if you’re growing squash or other related plants. These insects have a particular taste for cucurbits, such as pumpkins and zucchinis. In this article, we will explore what squash bugs eat and how they can affect your garden.

You might have noticed these pesky bugs on your squash plants, causing damage to the leaves and fruit. Squash bugs, scientifically known as Anasa tristis, feed on the sap of cucurbit plants by using their piercing-sucking mouthparts. This feeding activity results in the stippling of leaves and can lead to yellowing, tattering, and reduced yield.

It’s essential to be aware of the signs of squash bug infestations, such as the presence of their eggs or seeing nymphs and adults crawling around your plants. By understanding what squash bugs eat and their lifecycle, you can take steps to protect your garden from these destructive pests.

Understanding Squash Bugs

Squash bugs are a type of insect that can cause damage to your garden, particularly to plants like squash and pumpkins. These insects, scientifically known as Anasa tristis, have a distinct appearance that makes them easy to identify. The adult squash bugs are dark gray to dark brown in color and have a flat, oval shape. They measure about 5/8 inch long, making them relatively large for garden pests.

Their abdomens are another distinguishing feature of these insects. Squash bugs have alternating orange and brown stripes on their abdomens, which make them look somewhat similar to stink bugs. However, don’t let their appearance deceive you. These bugs can cause significant harm to your garden plants by sucking the sap from the stems and leaves.

To prevent squash bug infestations, you can take a few proactive measures:

  • Inspect your garden regularly for any signs of squash bugs, particularly near the base of your plants and under the leaves.
  • Remove any eggs or nymphs you find to prevent them from maturing into adult squash bugs.
  • Use an insecticidal soap or other garden-safe insecticides if necessary to control the population.

By understanding the characteristics and behaviors of squash bugs, you can take action to protect your garden and keep your plants healthy and thriving. Remember to stay vigilant and monitor your plants regularly for the best results.

Life Cycle and Reproduction of Squash Bugs

The life cycle of squash bugs begins with their eggs. Female squash bugs lay shiny, elliptical reddish-brown eggs that may be found singly or in clusters of 15 to 40. They typically lay their eggs on the underside of squash plant leaves.

These eggs hatch into squash bug nymphs, which progress through various stages before becoming adults. The nymphs range in size from 1/10 to 1/2 inch, and change color as they grow. Younger nymphs are greenish, while older ones turn brown.

Squash bug nymphs and adults mainly feed on the leaves and stems of their host plants. Their feeding can have a severe impact, causing leaves to yellow and die, and potentially reducing your plant’s growth and yield.

Squash bugs can reproduce rapidly, leading to large populations in your garden. They usually mate in the mid-summer, resulting in the next generation. A key factor to manage their population is recognizing their presence early, particularly by searching for their eggs on the plants.

During winter, adult squash bugs overwinter in sheltered places like garden debris, leaves, or even the cracks of your house. As temperatures warm up, they reemerge to mate and start the whole life cycle again.

To sum up:

  • Squash bugs lay reddish-brown eggs on squash plant leaves
  • Eggs hatch into nymphs that feed on the plants
  • Nymphs progress through stages and become adults
  • Adults mate in mid-summer and produce the next generation
  • Squash bugs overwinter in sheltered places and reemerge in warmer temperatures

Recognizing Squash Bug Infestation

It can be quite frustrating when squash bugs invade your garden and start feeding on your squash plants. Early detection is essential to avoid extensive damage. Here’s how to identify and recognize a squash bug infestation:

In the beginning stages of infestation, your squash plants’ leaves may show yellow spots or slight wilting. At this point, it’s wise to thoroughly check the undersides of leaves and around the stems. Squash bugs often lay their eggs in these areas, appearing as bronze, oval-shaped specks.

When examining the leaves, stems, and vines, be on the lookout for adult squash bugs. They are brown or gray and about 5/8 inch long with a characteristic triangular-shaped thorax. You might also spot nymphs – smaller, light gray bugs with black heads and legs, which eventually turn brownish-black as they grow into adulthood source.

In addition to visual signs, you may also notice:

  • Adult bugs congregating in groups
  • Leaves displaying extensive wilting
  • Leaves turning brown and eventually dying off

Remember, prevention and early detection are crucial to keep squash bugs from potentially decimating your garden. Stay vigilant and frequently inspect your squash plants for potential infestations.

Squash Bugs Diet and Feeding Habits

Squash bugs are known for attacking plants in the cucurbit family. They primarily feed on squash plants, but also affect pumpkins, zucchini, cucumber, melons, gourds, and other cucurbits. We will focus on their feeding habits and the damage they cause to these plants.

Squash bugs target leaves, stems, and sometimes fruits of these plants. They suck the sap out of the plant tissues, leaving behind a trail of destruction. Feeding on leaves produces small white dots or stipples, and leaves eventually appear tattered. When squash bugs attack in large numbers, they can cause leaves to yellow and die, significantly reducing the plant’s growth and yield.

Here’s a comparison of the common cucurbit plants squash bugs generally target:

Cucurbit Plant Susceptibility to Squash Bugs
Squash High
Pumpkins High
Zucchini Moderate
Cucumber Moderate
Melons Moderate
Gourds Low

Adult squash bugs are easily identifiable by their flattened, large, dark gray or brown appearance. Their abdomens have alternating orange and brown stripes1. The nymphs hatching from the eggs are smaller in size, ranging from 1/10 to 1/2 inch long.

To prevent damage from squash bugs, it’s important to:

  • Regularly inspect your plants for signs of infestation.
  • Remove and destroy any eggs or nymphs found.
  • Employ natural predators, such as ladybugs, to help control the squash bug population.

By understanding squash bugs’ diet and feeding habits, you’ll be better equipped to protect your cucurbit plants and enjoy a healthy harvest.

Effects of Squash Bugs on Your Garden

Squash bugs can cause significant damage to your home garden, especially if left unchecked. These pests feed on plants in the cucurbit family, which includes squash, pumpkins, and cucumbers.

Damaged Foliage

One of the most common signs of squash bug infestation is the appearance of small yellow-green or white spots on the plant leaves, known as “stippling.” Over time, the leaves become tattered, yellow, or scorched, leading to reduced growth and yield [1].

Impact on Plant Health

Both nymphs and adults feed on plant sap, causing leaves to wilt and yellow, eventually leading to plant death if the infestation is severe enough [2].

Weakened Fruit

Squash bugs don’t only feed on leaves and stems. They may also attack your fruit, causing localized damage [3].

Controlling Squash Bug Populations

To keep your garden healthy and prevent a squash bug infestation, consider the following strategies:

  • Rotate crops to break the life cycle of the pests.
  • Inspect your plants regularly for signs of damage or egg clusters.
  • Hand-pick and dispose of squash bugs and their eggs.
  • Use row covers to protect your cucurbit crops.
  • Plant resistant varieties when available.

With some vigilance, you can help keep your yard and garden free of these troublesome pests and maintain healthy, thriving plants.

Squash Bug Control and Prevention Methods

To effectively kill and control squash bug pests, various methods can be employed. One approach is using insecticides. For example, applying Permethrin can help reduce the infestation^[1^]. However, make sure to follow the label instructions and choose a resistant product.

A more hands-on approach for squash bug control involves hand removal. You can:

  • Scrape the eggs and nymphs off the plant leaves
  • Flick adult bugs into a container of soapy water to eliminate them
  • Regularly inspect your plants to maintain a bug-free environment

Another effective practice for squash bug prevention includes using row covers. These covers act as a physical barrier between the squash plants and pests, protecting the former from infestations. Be mindful of the weather when using row covers; ensure proper ventilation to prevent overheating.

Here’s a comparison of the methods described above:

Method Pros Cons
Insecticides Efficient pest control May harm non-target organisms
Hand removal Chemical-free; low-cost Time-consuming; labor-intensive
Row covers Prevents infestations; chemical-free Requires maintenance; attention to weather

Remember, employing a combination of these strategies will give the best results in controlling squash bug populations and preserving your plants’ health.

Natural Predators and Non-Chemical Deterrents

Tachinid flies are efficient predators of adult squash bugs. These flies lay their eggs on the outer surface of squash bugs, and their larvae then feed on the host, eventually killing them. You can attract these beneficial flies to your garden by planting flowers like nasturtium, which provide them with nectar.

Another helpful predator is the spined soldier bug. This insect feeds on the eggs and nymphs of squash bugs. To protect your plants, you can encourage the presence of these natural predators by planting pollen and nectar-producing flowers to attract and sustain them.

To keep squash bugs away, practice early morning patrols. Squash bugs are more visible and slower-moving in the early mornings, making it an ideal time to hand-pick them off your plants. Be consistent in your morning checks, as removing these pests early on can control their population and prevent severe damage to your crops.

To further deter squash bugs, you can also use barrier methods:

  • Install garden mesh around your plants, which keeps pests from reaching them.
  • Lay boards on the ground near the affected plants. The bugs are likely to hide under these, giving you a chance to find and dispose of them in the morning.

Moreover, you can plant nasturtiums around your garden, which not only attract beneficial predators but also help deter squash bugs. Nasturtiums release a strong odor that repels the pests, keeping your squash plants safe.

In conclusion, adopting natural and non-chemical deterrents can effectively control squash bug populations and protect your plants without jeopardizing the health of pollinators and other useful insects. Always keep in mind to use these methods consistently and early in the season for the best results.

Squash Bugs and Other Garden Threats

Squash bugs, overwintering in plant debris, can pose a significant challenge for your garden. These pests not only feed on the leaves and stems of your squash plants, but also introduce other threats such as stink bugs, aphids, bacterial wilt, cucumber beetles, and toxins.

These insects damage your plants in various ways, some examples include:

  • Stink bugs: piercing through plant tissues, causing discolored spots and deformed fruits.
  • Aphids: sucking the sap from plants, weakening them, and spreading disease.
  • Bacterial wilt: a disease transmitted by cucumber beetles, which blocks the transport of water and nutrients in the plant.

To minimize the damage, you can implement some best practices:

  • Remove plant debris regularly to reduce overwintering hiding spots for squash bugs.
  • Inspect your plants frequently and remove any pests you find.
  • Use natural predators, like ladybugs, to control aphid populations.
  • Employ sticky traps to capture cucumber beetles.

Here’s a comparison table of the common garden threats mentioned:

Garden Threat Transmission/Damage Control Methods
Stink bugs Piercing plant tissues Hand-picking, insecticidal soaps, organic sprays
Aphids Sucking plant sap Natural predators, insecticidal soaps
Bacterial Wilt Spread by cucumber beetles Sticky traps, crop rotation
Cucumber Beetles Feeding on plant tissues Sticky traps, organic sprays

By understanding these threats and their control methods, you can keep your garden healthy and ensure a bountiful harvest.


  1. UMN Extension

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.

Letter 1 – Squash Bug Nymphs


Bug obliterating my squash
July 20, 2009
I recently noticed some of my squash browning on the leaves and yellowing on the stems. Upon further investigation I found these bugs I have never seen before and they are ravishing my zucchini. Can you please help identify them so I can remove them?
North Central West Virginia

Squash Bug Nymphs
Squash Bug Nymphs

Hi D.K.,
These are nymphs of a Squash Bug in the genus Anasa, which can be verified by this photo on BugGuide.
The most likely member of the genus is Anasa tristis, and BugGuide has this to say about this injurious species:  “This is the most injurious species of coreid in Florida (3)  Injects a toxic saliva into plants, causing wilting and blackening of leaves. Can also act as vector of cucurbit yellow vine disease, which kills plants.”

Letter 2 – Squash Bug Hatchlings will NOT damage PANTS


Subject: underside of zucchini leaves
Location: northeast ohio
July 22, 2014 4:18 pm
A friend who runs a small busy found these on the underside of a leaf. This was today, so high summer. We want to know what this is and whether they will damage the pants
Signature: golly

Squash Bug Hatchlings
Squash Bug Hatchlings

Dear golly,
These are eggs and newly hatched Squash Bugs,
Anasa tristis, and there is on older, but still immature individual near the center of the group.  You can compare your image to this excellent series of images on BugGuide.  Squash Bugs will not damage your pants, but according to BugGuide:  “the most injurious coreid in FL causes wilting and blackening of leaves; can transmit cucurbit yellow vine disease.”  While they will not damage your pants, the are quite injurious to squash plants.  As you can see from the BugGuide Data page, they are not limited in range to Florida. 


  • Bugman

    Bugman aka Daniel Marlos has been identifying bugs since 1999. whatsthatbug.com is his passion project and it has helped millions of readers identify the bug that has been bugging them for over two decades. You can reach out to him through our Contact Page.

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  • Piyushi Dhir

    Piyushi is a nature lover, blogger and traveler at heart. She lives in beautiful Canada with her family. Piyushi is an animal lover and loves to write about all creatures.

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Tags: Squash Bug

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3 Comments. Leave new

  • Squash Bug Hatchlings will NOT damage PANTS

    This post appears to have a typo (missing the “L” in plants)… thought you might want to know in case you wish to correct it, thanks for sharing!

    • We do not make corrections in identification requests, so our response was directly related to the inquiry about damaging “pants.”
      P.S. Many people also want “buts” identified.

  • Squash Bug Hatchlings will NOT damage PANTS

    This post appears to have a typo (missing the “L” in plants)… thought you might want to know in case you wish to correct it, thanks for sharing!


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