How to Prevent and Get Rid of Cucumber Beetles

Cucumber beetles feed directly on plants, causing visible damage, and they may carry a bacterium that causes leaves to wilt. Infection typically occurs when plants are half-grown.

Close-up of adult striped cucumber beetle on cucumber leaf
Cucumber beetles can be striped or spotted. Photo Credit: G. J. Holmes, Valent USA Corporation, Bugwood.org
Cucumber beetles can be striped or spotted. Photo Credit: G. J. Holmes, Valent USA Corporation, Bugwood.org

Your beautiful cucumber plants suddenly look like they're wilting, being chomped, or maybe even both. What's at work? It could be cucumber beetles. Don't panic! There are plenty of things you can do to keep them out of your garden. Let us teach you how to identify, prevent, and get rid of cucumber beetles.

How to get rid of cucumber beetles.

What are cucumber beetles?

Cucumber beetles feed on leaves and roots of plants in the cucurbit family—namely, cucumbers, squash, melons, and pumpkins. You may see striped cucumber beetles, spotted cucumber beetles, or both. Both types are yellow and black and approximately 1/5-inch long.

Adult cucumber beetles lay eggs at the base of plants in spring. Once they turn into skinny, white larvae, they burrow into the roots. A serious attack can destroy an entire root system.

Cucumber beetles can also transfer diseases, such as bacterial wilt, that are often more damaging to plants than the beetles alone. When beetles feed on cucumber vines, they transmit the bacteria to healthy plants. The bacteria multiply and travel quickly throughout the vine. Once a plant is infected with bacterial wilt, it's virtually impossible to save. It's important to note, though, that squash bugs and squash vine borers can cause similar damage, so be sure you know what pest you're dealing with before treating.

How do I prevent cucumber beetles?

Outsmarting cucumber beetles is a matter of creating barriers, eliminating hiding places, and growing the right plants.

  • Use floating row covers to prevent beetles from infecting plants. When plants begin to flower, remove the covers so bees and other insects can pollinate blossoms. Learn more about floating row covers.
  • Choose non-bitter "burpless" cucumber varieties, such as Burpless hybrid cucumber and Burpless Bush hybrid cucumber, which attract fewer cucumber beetles than many older varieties.
  • Attract bumblebees. Planting borage, scarlet runner beans, and other flowers near your cucumbers attracts bumblebees, whose presence helps deter cucumber beetles.
  • Grow repellent plants. Flowers like nasturtium and marigolds, an herb such as catnip, and veggies like radishes and corn help keep cucumber beetles away.
  • Keep the garden clean. Cucumber beetles can overwinter in garden debris, so clean your garden thoroughly, especially at the end of the season.

How do I control cucumber beetles?

When it comes to getting rid of cucumber beetles, you have options.

  • Fill yellow pails or yellow plastic butter dishes with soapy water. Beetles will fly in and drown.
  • Buy traps. Yellow sticky traps work well, or you can buy traps specifically designed to catch cucumber beetles.
  • Spray an insecticide, such as Ortho® Insect, Mite & Disease 3-in-1, following label instructions carefully. Spray blooming plants in the early morning or in the evening, when beneficial pollinators are less likely to be active.

Need more info and local pesticide recommendations? Contact your regional Extension agent. You can find the nearest Extension office through the Cooperative Extension System map.

Don't let your cucumber plants become a snack. By choosing companion plants that deter cucumber beetles and practicing good garden hygiene, you can help keep these pesky bugs at bay. And if you do get an infestation, you can treat them in a number of ways.

Adult striped cucumber beetles on a pumpkin blossom. Photo credit: Howard F. Schwartz, Colorado State University, Bugwood.org
Adult striped cucumber beetles on a pumpkin blossom. Photo credit: Howard F. Schwartz, Colorado State University, Bugwood.org
Cucumber beetle damage on a melon. Photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org
Cucumber beetle damage on a melon. Photo credit: Whitney Cranshaw, Colorado State University, Bugwood.org