Cucumber beetles stuck to a trap. Credit: Courtesy of Susan Mulvihill

Cucumber beetles can wreak havoc on your cucumber crops. Luckily, there is an easy DIY way to keep them at bay. The following is an excerpt from “The Vegetable Garden Pest Handbook: Identify and Solve Common Pest Problems on Edible Plants” by Susan Mulvihill, published by Cool Springs Press on April 27, 2021.

Cucumber beetles are extremely damaging in the vegetable garden. In addition to munching on cucurbit family crops (cucumbers, melons, pumpkins, and summer and winter squash), these pests will also feast on asparagus, beans, beets, corn, potatoes, and tomatoes. As if that wasn’t bad enough, they transmit two diseases, bacterial wilt and cucumber mosaic virus.

The adult beetles chew on the flowers, fruits, and stems of any of the previously mentioned vegetable plants. After the females lay eggs in the soil around the base of their preferred larvae hatch and feed on the plants’ roots. By trapping the adults, you can disrupt their life cycle.

This project takes advantage of the fact that the color yellow and the scent of clove oil, which mimics the odor of their pheromones (mating hormones), attract the beetles. The trap is simple and quick to make and doesn’t require any special tools. The project as described here makes one trap.

Supplies

— 16-ounce yellow plastic drinking cup (the plastic makes the trap waterproof)

— Hole punch

— 2 twist-ties (from bread bags or grocery produce bags)

— 1 bamboo garden stake the height of your mature crop

— Sticky coating for insects (available at garden centers and online) or petroleum jelly

— Disposable gloves

— Wooden craft sticks, optional

— Cotton ball or round cotton pad

— Clove oil

— Eyedropper

Steps

— Use the hole punch to make 2 holes just below the lip of the cup, spaced about 1/2 inch (1.3 cm) apart.

Use the hole punch to make 2 holes just below the lip of the cup for a cucumber beetle trap. Credit: Courtesy Susan Mulvihill

— Secure the cup to the stake with a twist-tie for each hole, as shown.

Secure the cup to the stake with a twist-tie for each hole, as shown, for a cucumber beetle trap. (Photo courtesy Susan Mulvihill)

— Put on your disposable gloves.

— Spread a small amount of the sticky coating or petroleum jelly onto the inside bottom of the cup. The craft stick is helpful for this.

Spread a small amount of the sticky coating or petroleum jelly onto the inside bottom of the cup for a cucumber beetle trap. Credit: Courtesy of Susan Muvilhill

— Place the cotton ball or cotton pad onto the sticky coating or petroleum jelly in the cup bottom.

— Hold the stake and coat both the inside and outside of the cup with more sticky coating or petroleum jelly. If you get any of the sticky coating on your skin, use mineral oil, baby oil or waterless hand soap to remove it.

— Use the eyedropper to apply a few drops of clove oil to the cotton inside the cup.

— Push the stake into the soil so the trap will be directly above the crop you are trying to protect. I used a 3-foot-long (91 cm) stake but you might need a taller one, depending on the height of your crop.

A staked cucumber beetle trap in the garden. Credit: Courtesy Susan Mulvihill

— Monitor the trap frequently. As long as you are trapping cucumber beetles, refresh the sticky coating or replace the trap every 2 to 4 weeks. If it catches too many beneficials, remove it from the garden.