Learning how to make your own cucumber beetle trap can save you a lot of trouble and prevent the need for pesticides. In this article, I’ll share the easy DIY cucumber beetle trap I’ve been using for years. It doesn’t cost much to make using only simple household materials and only takes a few moments of your time to set up.

Meet the cucumber beetle

Cucumber beetles are common pests of all cucurbits, including melons, like watermelon and cantaloupes, gourds, squash, and pumpkin, but they can wreak particular havoc on cucumber plants. They chew ragged holes in the foliage and stems and transmit deadly bacterial wilt. Small seedlings are particularly vulnerable, though mature plants are affected as well.

There are a few different species of cucumber beetle: the striped cucumber beetle (Acalymma vittatum) and the spotted cucumber beetle (two subspecies: Diabrotica undecimpunctata howardi and D. undecimpunctata undecimpunctata). Both striped and spotted cucumber beetles measure about ¼” long at maturity. No matter where you live in the continental United States, one or both species calls your area home.

Why trap cucumber beetles?

Cucumber beetles spend a good part of their life cycle as eggs and larvae underground. Cucumber beetle larvae live in the soil, where they feed on the plant’s roots. When the time is right, they pupate into adults that feed on plant foliage.

Since the adults are flying insects, controlling them with pesticides is challenging, especially if you are an organic gardener who typically relies on insecticidal soap or horticultural oil, neither of which is effective against adult cucumber beetles. Rather than repeatedly spraying your cucumber plants with pesticides to manage feeding damage and minimize the potential for bacterial wilt transmission, it is smarter to try to trap the beetles instead. This keeps pesticides off your plants and reduces beetle feeding damage.

Materials to make a cucumber beetle trap

While some gardeners use commercially available yellow stick cards to try to trap cucumber beetles, I find it’s less expensive to DIY my own cucumber beetle traps. I make several of these sticky traps each year and find them to be very effective. Here are the materials you’ll need:

• Yellow plastic cups
• Tanglefoot Tangle-Trap non-drying glue
• Cotton balls
• Clove essential oil
• Hole punch
• Twist ties
• Bamboo stakes

How to make a cucumber beetle trap

The yellow plastic cups turned on their sides mimic squash flowers, which is one of the favorite pollen sources of cucumber beetles. The idea is that they fly in, but they don’t fly back out because they get trapped in the glue. Here are the steps you’ll follow to make this DIY cucumber beetle trap.

1. First, use the hole punch to make two small holes near the rim of the cup, about ½” apart. The cup will be hung on its side in the garden.
2. Run a twist tie through each hole. One loose end should come out the top of the cup, the other out of the hole.
3. Twist the two loose ends of each twist tie around a bamboo stake so the outside of the cup is sitting against the stake and the cup is on its side.
4. Holding only the bamboo stake, coat the entire inside and outside of the cup with the Tangle-Trap. This wet-glue adhesive does not dry and remains extremely tacky in order to trap these destructive pests. Be careful not to get any of this super sticky glue on your body, clothes, or furniture. It is very difficult to remove. Do this step outdoors.
5. Stick the base of the stake into the garden using the placement instructions in a later section of this article.
6. Once your trap is in place, soak a cotton ball in clove essential oil and toss it into the bottom of the cup.

How this cucumber beetle trap works

These traps act as cucumber beetle lures, thanks to the essential oil in clove oil (called eugenol) which mimics the mating pheromone of cucumber beetles. They are attracted to the clove oil-soaked cotton ball, enter the yellow plastic cup, and get stuck in the glue. These cucumber beetle traps serve as both a floral lure and a pheromone lure to capture these pests. The beetles get trapped on both the inside and the outside of the cup.

Where to set your cucumber beetle trap

Where to set your DIY trap depends on whether you’re growing your cucumber plants along the ground or training them to grow up a trellis. Since the purpose of a cucumber beetle trap is to mimic the flowers, for plants sprawling along the ground place the traps so they sit about 2 to 4 inches above the plant tops. Plan to place a trap every 6 to 8 feet along the crop row. For raised beds or block-style planting, place one trap for every 20 to 25 square feet.

If you’re growing your cucumbers up a trellis, place the traps about 2 to 3 feet above the ground. You can experiment with higher or lower elevations based on the number of beetles you trap and how tall your trellis is.

Trap maintenance

There are a few things you’ll need to do to maintain your cucumber beetle traps. Use a pair of tongs to remove the cotton ball every week or two and add a few more drops of clove oil.

Though Tangle-Trap glue is non-drying, it may eventually become “clogged” with dead insects, leaf litter, dust, and other debris. When this happens, replace your non-toxic trap with a new one by removing the old cup and replacing it with a new one covered in a fresh coating of Tangle-Trap. My traps fade and get pretty beat up by the end of the growing season, so I make new ones each year.

I put my new cucumber beetle traps up about two weeks after planting my cucumber seeds out into the garden. I often insert the bamboo stakes far into the ground when the seedlings are young, and then gradually pull them up out of the ground a little at a time as the plants grow to make the cups sit higher up. Play around with this to find what works for you.

The potential for collateral damage

I’m not going to lie. You will find other insects trapped in your cucumber beetle traps from time to time. Without the ultraviolet “landing strip” most real flowers have to attract pollinators like bees and butterflies, the cups thankfully don’t trap a lot of these beneficials. However, I do occasionally find a few small bees or a butterfly stuck in the glue. But I’ve also found carrot maggot flies, flea beetles, and some other pests on them over the years, but most of the insects trapped in the glue are striped and spotted cucumber beetles. If you find your traps are trapping more than your intended target, it may be best to skip using them. Use your own best judgement here.

DIY success

I hope you’ll enjoy making and using these clever DIY cucumber beetle traps as much as I do. I’ve found that I have less bacterial wilt and more of my seedlings survive to maturity. Happy DIYing!

For more information on natural pest control, please visit the following articles:

• Managing slugs 
• Controlling cabbageworms 
• Broccoli bug management
• Tomato caterpillars 
• Squash bugs