How to avoid early season pests in your vegetable garden

Sometimes I wonder if food from my own garden tastes better simply because of the effort that went into growing it.

The work really isn’t too bothersome. There’s the initial preparation and planting phases, which can be quite time consuming. However, the maintenance that follows is easy enough to keep up — most of the time.

It’s nice when things work out exactly how you thought they would. Prepare the soil. Plant the garden. Pull the weeds, water the seeds and nature the seedlings. Then after some waiting, you get rewarded with healthy plants and delicious fruits and vegetables.

At least that’s how you think it will go. But don’t count your chickens before they hatch, as they say.

While you’re daydreaming about all the delicious dishes you’ll be making in a couple weeks, the local pest population is setting up shop. What started as a small problem is suddenly destroying your plants and making all your hard work a moot point.

By learning to identify the common pests in the early season, you can isolate the problem and get rid of them before your bounty is lost. This year flea beetles, Japanese beetles, cucumber beetles, the squash vine borer and the imported cabbage worm have been wreaking havoc.

Flea beetles

There are several species of flea beetles to watch for this summer. They are tiny and metallic, measuring about 1/10 inch long. When disturbed their larger rear legs allow them to jump like a flea.

They are attracted to greens such as arugula, pak choi, eggplant and a few other plants. They cause a characteristic injury known as “shot-holing” — clusters of many small holes in leaves that resemble buckshot. Plants can generally survive the damage, but it will slow growth.

How to get rid of flea beetles

• Protect your vegetables with floating row covers as barriers against the bugs. However, they need to be in place before flea beetles are a problem.
• Rotating plant families in the garden can help. Learn more by reading All in the plant family: vegetable classification and cultivation.

Japanese beetles

This year Japanese beetles are emerging a little earlier than usual because of warmer weather. They are metallic copper colored with a green thorax and head.

Japanese beetles will eat any and all vegetables. They will consume leaves to the point of “skeletonizing” the plant.

How to get rid of Japanese beetles

• Scout your garden daily and remove them from your plants. Knocking them into a bucket of soapy water can reduce damaging populations.
• DO NOT use pheromone traps. They will attract a greater number of beetles to your yard.

Cucumber beetles

Adult cucumber beetles are yellow with either black spots or stripes. The measure about 1/5 inch long and 1/10 inches wide. The larvae of both species of cucumber beetle are creamy white colored and the eggs are a pale orange color.

Cucumber beetles will feed on plants on the squash family (cucurbits) and peppers. The larvae feed on cucurbit roots and underground portions of the stems, which generally doesn’t impact overall plant health much. However, once the adult beetles emerge they will feed on the plants’ foliage.

Additionally, they can cause bacterial wilt. The plant will appear drought stressed before eventually dying.

How to get rid of cucumber beetles

• Place floating row covers over susceptible plants until they bloom. Then remove them, so that blossoms can be pollinated.
• Plant a cultivar that has a resistance to bacterial wilt.
• Plant susceptible crops around June 15 to allude overwintering adults.
• Picking the beetles off your plants can help decrease populations and stop them from spreading. However, they are much faster than Japanese beetles and can be tough to contain.
• Eliminate weeds in and around your garden.
• Remove plants affected by bacterial wilt immediately to stop the disease from spreading.
• Remove garden debris at the end of the season to prevent cucumber beetle eggs and larvae from overwintering.

Squash vine borer

The squash vine borer is a clear-winged moth that actually looks more like an orange wasp. Its eggs are flat and brown and its larvae are white or cream-colored with brown heads.

The squash vine borer has been known to attack summer squash, winter squash and pumpkins. The grub-like caterpillars bore into susceptible plants’ stems to feed. They feed through the centers of the stems, blocking water flow to the rest of the plant. The first symptom of a borer attack is wilting. If the problem isn’t resolved, the plant will eventually die.

After four to six weeks of feeding, the squash vine borers burrow into the soil to pupate until next summer.

How to get rid of squash vine borers

• To manage the impact of the squash vine borer on your garden, you need to stop the larvae before it enters your plants. One method is to set out yellow colored containers filled with water to attract and trap the adults.
• If your plants are affected by the squash vine borer, pull and destroy the dead or dying plants to stop their spread.
• Plant a second crop of summer squash in early July, so it will mature after the adult borers have finished laying eggs for the year.
• Plant vine crops that are not as attractive to the squash vine borer, such as butternut squash, cucumbers, melons, and watermelons.
• Rotating plant families each year can also help manage these pests.

Imported cabbage worm

The imported cabbage worm is one of the first visitors to local gardens every spring. The small white butterflies with black wingtips are easily recognized. They lay their eggs on host plants early in the spring.

They are most attracted to broccoli, cabbage, cauliflower, kale, radishes, turnips and collards. The larvae will hatch and begin to feed on the leaves of its host plant.

How to get rid of imported cabbage worms

• Check the leaves of young plants for eggs and rub them off.
• Small larvae can be picked off and easily controlled with Bacillius thuringiensis — a microbial product that is very safe for beneficial insects and humans.
• Large larvae can be managed by removing them by hand, but Bt will not be effective.

Integrated pest management plans

While there are many different methods for dealing with various pests, some practices are consistent. Rotating plant families from year to year, managing weeds, using recommended spacing between plants and keeping a watchful eye to catch pest problems early are always good ideas.

Related Content

• All in the plant family: vegetable classification and cultivation

Resources

• Akron Beacon Journal, Plant Lovers’ Almanac: Early season pests in the vegetable garden
• University of Minnesota Extension, Cucumber beetles in vegetable gardens
• University of Minnesota Extension, Squash vine borer management in home gardens