Vegetable Pest Update

June and July are the growing months. The days are long and the sun is strong...

  • It is also a critical time to control pests. The first and possibly the most important pests are weeds. Weeds compete for light, moisture, nutrients, and space. Weeds carry disease and attract insect pests. Weeds also create an environment around the plant that is conducive to disease development. Shallow cultivation with a hoe is a great way to eliminate weeds while they are small. Tilling just the top half inch of soil is all that is needed when weeds are very small or just emerging. Hand pulling is still the only way to get up close to plants. While weeding is time consuming, it definitely pays big dividends through the rest of the season.
  • Insect pests that are currently active include cucumber beetles, flea beetles, slugs (not an insect), potato leafhoppers, and Colorado potato beetles. Cucumber beetles not only feed on you vine crop plants but also infect the plants with the bacteria that causes bacterial wilt. Flea beetles feed on most vegetable plants.
  • Flea beetles are small black beetles that appear to spring off of leaves when disturbed. They prefer to feed on potatoes, tomatoes, and their absolute favorite is eggplant. Their numbers increase as the plants grow causing stunting.
  • Potato leafhoppers have arrived. Potato leafhoppers migrate into our area from the south on wind currents. They are very small, lite green insects. They are small enough that they can come through your window screens. They feed on potatoes, carrots, and beans. They cause the leaves to turn yellow and stunting of the plant. Their populations will increase until mid-August. They are gone by mid-September.
  • The other insect pest that causes significant damage is the Colorado potato beetle. They feed on potato, tomato and eggplant. Eggplant is their favorite food. The adults are beetles with tan and brown stripes. The yellow/orange eggs are laid in groups on the underside of leaves. The larval stages of the beetle look like pale orange slugs with black dots on their sides. The larval stages do the most damage.
  • There is a relatively new biological insecticide that is both effective at controlling many of these insect pests and is less toxic than most other insecticides. The active ingredient is Spinosad. Many of the Spinosad formulated products are approved for organic production. Always read the label before using and do not spray when pollinators are present.
  • Vegetable diseases have not been a major problem so far but we expect that to change with the wetter weather. Early blight has been found on the lower leaves of some tomato plants. Late blight has not been confirmed in Pennsylvania yet.

For more information contact your local extension office. In Lackawanna County call 570-963-6842 or email

Contact Information

John Esslinger
  • Horticulture Extension
Phone: 570-316-6516