This pesky insect typically does damage to squash and pumpkins, but it may also attack the melon and cucumber family. It is a common insect in the Treasure Valley and throughout Idaho.
They cause damage to the leaves of these plants by sucking the sap out which in turn creates brown spots. Damage caused by squash bugs will inhibit the flow of nutrients to plants. When left unchecked, they can cause young plants to wilt and possibly die. There are several ways to control the damage. Since you likely will find extensive damage from these insects on young plants and again when they are in bloom, many gardeners simply pick them off and destroy the insect. One method is to pick them off and drop them into a pail of warm soapy water. If you are into using chemicals, we recommend Ferti-lome ‘Bug Blaster’ or Sevin insecticide. Both these chemicals are considered safe to use on nearly all vegetables. When using insecticides, always follow the instructions printed on the container. One positive to this insect is that they don’t carry diseases as many other insects do. Some gardening folks rotate their crops much like that of a farmer, however since most of us live on a small lot, this is not always practical. Some squash and/or pumpkins are somewhat resistance to squash bugs, but may not be a flavor that suitable to your taste palette. You will find that some varieties such as butternut, crookneck and acorn squash are not quite as prone to these insects as other varieties of squash and/or pumpkins.
The picture we attached was taken from our own garden in late fall. These adult insects are rather large, measuring a little over ½ inch long. You can often identify the eggs since they are a small, yellowish, orangish-bronzy color. We didn’t get a picture of them in early spring, but young squash bugs are grayish in color (In the picture, you will see one juvenile squash bug just below an adult). The squash bugs found in our fall garden were a dark brown and had orangish markings on their abdomens. With some protection such as garden debris, squash bugs often live through the winter, especially in mild winters. Gardening folks who compost material from their garden are perhaps the most prone to future insect damage since many insects can live in your compost bin. Come spring, they will fly to your favorite squash or pumpkin plants and feed. Female squash bugs will lay their eggs about every 10 days or so on the underside of the leaves. They start emerging toward the end of June and will lay eggs throughout the summer. Although the adults may live through the winter, the nymphs typically die as temperatures dip below 32 degrees.
Even healthy plants seem to be prone to squash bugs, so early detection is important. When you see eggs on the leaves, destroy the eggs by crushing them between your fingers/gloves.
If you have any questions on how to identify squash bugs or most any insect in your garden, stop by the Home & Garden Store. We’ll be happy to help you with all your gardening questions.