Controlling Vegetable Garden Insects without Pesticides

As a gardener who carefully tends vegetable beds, you do not want to see insects ruining your growing bounty. Fortunately, there are alternative to pesticides that can hurt beneficial bugs that help your plants. 

Here are some easy control measures that may avoid the need to use stronger methods.

Aphids


Aphids

The aphid is tiny and pear-shaped with long antennae and two tubes projecting from their abdomen. Usually found on most fruits and vegetables, flowers, ornamentals, and shade trees throughout North America, they feed on plant sap. This distorts the foliage, causing leaves to drop. The honeydew excreted from the aphid left on leaves encourages sooty mold growth and feeding spreads viral diseases. To control these bugs:

  • Wash plants with strong spray of water
  • Introduce native predators and parasites such as aphid midges, lacewings, and lady beetles
  • If possible, cover plants with floating row covers
  • Apply hot-pepper or garlic repellent sprays
  • For severe problems, apply horticultural oil, insecticidal soap, or neem oil

Caterpillar

Caterpillars

Caterpillars are the larva of a butterfly or moth, having a segmented wormlike body with three pairs of true legs and several pairs of appendages. Caterpillars may be hairy, have warning coloration, or be colored to resemble their surroundings.
They are found on many fruits and vegetables, ornamentals, and shade trees. Caterpillars chew on leaves or along margins; some tunnel into fruits. To deter them:


Cutworm

Cutworms

Cutworms are gray or black segmented larvae that are fat and about 1-inch-long. Mostly active at night, they are found on most early vegetable and flower seedlings and transplants throughout North America. Cutworms chew through stems at ground level; they may completely devour small plants in May and June. For control:

  • Use cutworm collars on transplants
  • Delay planting
  • Hand-pick cutworms curled below soil surface

Colorado Potato

Colorado Potato Beetle

The adult potato beetle is yellow-orange with ten black stripes on wing covers. They are found on potatoes, tomatoes, cherry tomatoes, eggplant, and petunias throughout North America. Potato beetles defoliate plants, reducing yields or killing young plants. To control:

  • Apply floating row covers
  • Use deep straw mulches
  • Hand pick
  • Attract native parasites and predators
  • Spray with neem oil

Mexican Bean Beetle

Mexican Bean Beetle

Adult Mexican bean beetles are oval, yellow-brown, 1/4-inch long with 16 black spots on wing covers. Their larvae are fat, dark yellow grubs with long, branched spines. These beetles are found on cowpeas, lima beans, snap beans, soybeans in most states east of the Mississippi River as well as parts of Arizona, Colorado, Nebraska, Texas, and Utah.
Adults and larvae chew on leaves from beneath, creating a lacy appearance. To control:

  • Apply floating row covers
  • Plant bush beans early
  • Hand pick
  • Plant soybean trap crop
  • Spray with insecticidal soap or neem oil

Flea Beetle

Flea Beetle

Flea beetles are small, dark beetles that jump like fleas when disturbed. Found usually on most vegetable crops, they are found throughout North America. Adults chew numerous small, round holes into leaves (most damaging to young plants), and larvae feed on plant roots. For control:


Japbeetle

Japanese Beetles

Japanese beetle adults are metallic blue-green, ½-inch long with bronze wing covers. The larvae are fat, white grubs with brown heads. They can be found on many vegetables, flowers, and small fruit in all states east of the Mississippi River. Adults skeletonize leaves, chew flowers, and may completely defoliate plants while larvae feed on lawn and garden plant roots. To control these insects:

  • Shake beetles from plants in early morning
  • Apply floating row covers
  • Set out baited traps upwind of your vegetable garden on two sides and at least 30 feet away
  • Spray beetles with insecticidal soap

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