Nothing fills a gardener with more hope than the sight of new sprouts rising from the ground. But that hope can turn to dread when that new growth starts showing evidence that a pest is helping itself to a meal from your garden long before your planned harvest.
In Maine, there are several early season pests that can damage those tender leaves and even destroy an entire planting. If you are seeing damage to your growing vegetables, here are four early season pests that may be responsible.
If your seedlings look like they have been cut near the base or munched from the top down, you may have cutworms. Cutworm larvae hide in the soil during the day and come out at night to feed. The cutworm most often feeds on a seedling stem and it attacks a wide range of plants including asparagus, beans, cabbage, peas, tomatoes, corn, carrots, lettuce and peppers.
Look for the cutworm during the day by gently moving the dirt around the base of your seedlings. You will likely find it curled up in a little ball just under the soil. The larvae are between one and two-inches long and are grey or dull brown in color.
There are several ways to control cutworm damage. They include wrapping the stems of individual plants with a band of tar paper or similar material, sprinkling diatomaceous earth on the dirt around the plant, picking the worms off the plants by hand or using an appropriate insecticide.
Evidence of the imported cabbageworm can be seen before you even plant anything. The worm is the larval stage of a white butterfly that you may have observed starting in April.
The butterfly will lay its eggs on the underside of your transplanted vegetables or early sprouting seeds of the mustard family including cabbage, cauliflower, broccoli and kale. It’s a greenish, slow moving caterpillar that feeds on the underside of the leaves or on the heads of cauliflower, cabbage and broccoli as it starts to grow.
Natural repellents like pyrethrin or Bacillus thuringiensis — also known at BT — can help control cabbageworms and you can also hand pick the worms off your plants. Floating row covers can help keep the butterflies from getting to your plants in the first place. There are chemical pesticides available to control this pest.
The flea beetle is a pest that damages crops below and above ground. This tiny, hopping insect commonly feeds on broccoli and cauliflower. The larval form of the beetle are root eaters and tunnel into your plant’s roots causing damage. When the beetle is mature, it moves above ground and feeds on the plant’s leaves and forming heads.
Flea beetles can be black, bronze, brown, bluish or grey. Some have stripes and all have large back legs that makes them champion jumpers — especially when disturbed.
Dusting your plants with plain talcum powder will repel flea beetles. White, sticky bug traps will capture flea beetles as they jump. Chemical insecticides can also be used, but work best when applied early in the season.
Colorado Potato Beetle
The damage to your potato plants from the Colorado potato beetle will come in two waves over the season. The beetle spends all winter in the soil. In the spring, it emerges and walks to the nearest potato plant or any member of the nightshade family, including tomatoes, eggplants and peppers. The beetle will feed on these plants and lay its yellowish-orange eggs on the underside of the leaves. About two weeks later those eggs hatch and the larvae will start to move around the plant, eating leaves as it goes.
The adult beetle is less than one-quarter inch long and has yellowish white wings with 10 narrow, black stripes. The larvae are pink or salmon colored to brick red with black heads and two rows of dark spots on either side of its body.
Lining the trenches between your rows or heavily mulching with straw can help keep the potato beetles from getting to your plants. You can also pick them off your plants by hand or use chemical insecticides.