Aphid, Whitefly, & Common Pests

Tomatoes are delicious not only to us but to a host of garden pests! Aphids, whiteflies, and several others can stunt growth, spread disease, and ruin fruit. Here’s how to identify, prevent, and control the most common tomato pests for healthy, thriving plants.

Aphids

• Identification:
  Tiny, soft-bodied green, yellow, black, or gray insects clustering on new stems, leaf undersides, or flower buds.
• Symptoms:
  Curling, sticky (“honeydew”) leaves, stunted growth, distorted shoots, and the presence of ants.
• Solution:
  • Blast off with a strong spray of water.
  • Spray with insecticidal soap or neem oil.
  • Introduce beneficial insects (ladybugs, lacewings).
  • Encourage birds in your garden.

Whiteflies

• Identification:
  Small, white, moth-like insects that flutter up when plants are disturbed.
• Symptoms:
  Yellowing leaves, sticky residue, mold, and general plant weakening.
• Solution:
  • Use yellow sticky traps to catch adults.
  • Spray undersides of leaves with insecticidal soap or neem oil.
  • Remove heavily infested leaves.
  • Ventilate well in greenhouses.

Spider Mites

• Identification:
  Pinhead-sized, often red or yellow, with fine mottling and webbing on leaves.
• Symptoms:
  Speckled, bronzed leaves, fine webbing, leaf drop.
• Solution:
  • Mist plants (mites hate humidity).
  • Blast undersides of leaves with water.
  • Use predatory mites or insecticidal soap if infestation is bad.

Tomato Hornworm & Caterpillars

• Identification:
  Large green caterpillars, up to 3 inches long, with a horn on the tail end.
• Symptoms:
  Chewed leaves and stems, missing fruit chunks, dark droppings.
• Solution:
  • Hand-pick and remove.
  • Encourage birds and wasps.

Leaf Miners

• Identification:
  Winding, pale trails inside leaves.
• Symptoms:
  Trails, blotchy foliage.
• Solution:
  • Remove affected leaves.
  • Use row covers to exclude adult flies.

Prevention Tips

• Inspect plants regularly, especially the undersides of leaves.
• Encourage beneficial insects by planting marigolds, borage, or alyssum.
• Rotate tomato crops and control weeds.
• Clean up garden debris at season’s end.

When to Use Organic Sprays

• Always as a last resort.
• Spray in the evening to protect pollinators.
• Rotate products to minimize resistance.