Squash Bug
A flat, gray-brown shield-shaped bug about half an inch long that hides under squash leaves and at the base of the plant. It sucks sap, so leaves go speckled, then yellow, then brown and crisp, and whole runners wilt as if someone cut the water off.
Pest checklist
Four things to look for. If most of them match what you are holding, you are in the right place.
What gets rid of them
Gentlest option first. For most backyard cases the first one is enough, so try these in order and stop as soon as it works. If you do spray something, the product label tells you how — please read the notice further down.
1Crush the eggs
Check leaf undersides twice a week from June on and rub off every egg cluster with your thumb or a scrap of duct tape.
Try this first2Trap them under a board
Lay a scrap board or folded newspaper flat on the soil next to the plants at night, then lift it in the morning and drop the bugs into soapy water.
3Cover young plants
Put floating row cover over the bed at planting and take it off when the first female flowers open so bees can get in.
floating row cover garden fabric4Spray only the small nymphs
If nymphs are swarming the crown, use insecticidal soap or a neem product on them late in the day; grown adults shrug it off.
insecticidal soap concentrate garden
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Which plants get squash bug
Every plant we cover that gets squash bug, grouped by type — tap any one to open its page. A note beside a plant came from that plant’s own entry, because the same pest can be a minor nuisance on one plant and a serious problem on another. Plenty of plants we do not cover get it too.
Plant families hit hardest
Related plants often share the same problems, so if one plant in a family has it, check the others. The largest group here is Cucurbitaceae, with 5 of the 5 affected plants.
- Cucurbitaceae5 plants
When to treat
Start turning leaves over in June and crush every egg cluster you find, because sprays only work on the youngest nymphs and by the time you notice adults it is usually too late for that season.
Timing only — the label is the law
This page tells you when to watch for squash bug and when treating is worth considering. It is not a recommendation to apply any particular product. Read and follow the product label before you spray — under federal law the label is the legal instruction, and using a pesticide against it is illegal.
- Check the pre-harvest interval. Every product that’s cleared for an edible crop sets a minimum number of days between spraying and picking. Find it on the label before you spray anything you intend to eat.
- Check the re-entry interval before you or anyone else works in the treated area again, and use the protective equipment the label names.
- Confirm the product is registered for your crop in your state. This page groups many different crops together, and a product legal on one of them is not legal on all of them — state registrations differ too. Your state pesticide agency or local extension office can confirm both.
- Rates and mixing instructions come from the label, never from us. We don’t publish them because they differ by product and formulation.
Other problems on the same plants
If a plant gets squash bug, these are the problems it most often gets as well, so they are worth checking for while you are out there. They tend to appear together; one does not cause another.