The Cucurbitaceae family has over 900+ species, and most have a vining growth habit that sprawls or uses tendrils to climb. Common cucurbits include cucumbers, zucchini, summer squash, watermelons, winter squash, and pumpkins. This summer we have a variety of cucurbits in the Edible Garden, and with these plants comes a variety of challenges with pests. If you suspect insects are damaging your plants this summer, your first mission is simple: get a positive ID.
Squash Bug
Squash Bugs are sap-sucking true bugs that feed on the leaves of cucurbits. The species pictured is a Horned Squash Bug (Anasa armigera), distinguished by two small “horns” surrounding its antennae. The common Squash Bug (Anasa tristis) has a similar body shape. The damage from the feeding of these bugs will cause yellow spots on the foliage. This can also cause plants to wilt due to the interrupted nutrient cycle. Fruit is occasionally fed on which can cause deformities and rot.
Adult Squash Bugs overwinter in plant debris. Through spring and summer, the females will begin to lay eggs. The copper eggs are oval shaped and are laid in groups on the leaves. The eggs hatch in less than two weeks. Nymphs can be somewhere between a green and gray color until they mature.
Cucumber Beetle
Cucumber Beetles feed on the leaves, flowers, and occasionally the fruit of cucurbit plants. The species pictured is the Spotted Cucumber Beetle (Diabrotica undecimpunctata), but there is also the Striped Cucumber Beetle (Acalymma vittatum). They are both yellow in color and have black spots or stripes.
These beetles can cause a variety of issues for your plants. In high numbers, they can easily defoliate an entire plant. Large groups can also cause pollination issues inside flowers by disrupting access to pollinator species. They can also carry and spread Bacterial Wilt and Squash Mosaic Virus.
Cucumber Beetles overwinter in protected areas or in plant debris. They emerge in spring, lay their eggs around the base of the cucurbit in the soil. The larvae, once hatched, will also then begin to feed on the roots causing further damage. They will emerge as adults in late summer and begin the cycle again.
Squash Vine Borer
Squash Vine Borer moths are orange bodied with unique black dots on their abdomen. They have clear metallic wings and fly during the day. They emerge from the soil in summer and begin laying tiny brown eggs at the base of a cucurbit plant. When the larvae hatch from the egg, they then burrow into the plant’s stem to feed. This damage will cause severe wilting because it interferes with the plant’s ability to uptake water. Once the larva reaches full-grown maturity, it will leave the stem and overwinter in the soil until next season. There is typically only one generation per season, although two generations have been documented in Kentucky.
Management
It is wise to use preventative measures to reduce pest pressure in your garden. Since many insects overwinter in the soil, it is helpful to rotate your cucurbits every couple of years. You can also keep numbers down by creating habitat for birds and predatory insects.
Mesh row covers can keep plants safe from new insects that may be attracted to your cucurbits. You will need to open the ends of the row cover when flowering begins to ensure successful pollination.
When working in the garden, monitor your plants for activity. Removing insects and eggs manually is effective. Be sure to check the underside of the leaves. Use caution when using insecticides, because they can also harm beneficial insects.
Remember – pests will always find their way into the garden, and you can still have a healthy and productive garden when they are present. Each species listed here is in the Edible Garden this year, and our squash and zucchini plants are as prolific as ever!
