Leafhopper Infestation in a Garden

Common Green Leafhopper (via Wikimedia Commons, CC BY 2.0)

Leafhoppers are small, green or brown insects that can cause damage to plants by feeding on the sap of leaves and stems. They are most commonly found on plants in gardens and landscapes, but can also infest indoor plants. 

Symptoms of Leafhopper Infestation

  • Yellowing or discoloration of leaves
  • Wilting or stunted growth
  • Presence of small, green or brown insects on leaves and stems
  • Stippling or discoloration on leaves, caused by the insects feeding on the sap
  • Leaves may also curl or have a rough texture
  • Honeydew excretion which can lead to sooty mold growth

What a Leafhopper Looks Like

  • Small, typically less than 1/4 inch in length
  • Green or brown in color
  • Triangular shape body
  • Long legs and antennae
  • Can jump and fly quickly
  • Often found on the underside of leaves

Treatment Options

It is important to note that multiple methods may need to be used in combination to effectively control a leafhopper infestation. It’s also important to monitor the leafhopper population regularly and take action as soon as an infestation is detected to prevent the population from becoming established and causing significant damage to the plants.

Cultural Control

  • Keep the plants healthy by providing them with proper care, including adequate water and fertilizer.
  • Remove and destroy any infested plants to prevent the leafhoppers from spreading to other plants.
  • Keep the area around the plants clean, removing any debris that can harbor the pests.
  • Properly prune and dispose of any infested branches and leaves.
  • Avoid overcrowding plants, as this can make it easier for leafhoppers to spread from plant to plant.

Physical Control

  • Use a strong stream of water to wash leafhoppers off plants. This can be done with a hose or a powerful spray nozzle on a watering can.
  • Use sticky traps to trap adult leafhoppers. These can be purchased or made at home by covering cardboard or plastic with a sticky substance like Tanglefoot or Vaseline.
  • Use Row Covers, These are lightweight, sheer fabric barriers that are placed over plants to physically exclude pests.

Biological Control

  • Encourage natural predators such as ladybugs, lacewings, and pirate bugs to visit the garden by planting flowers that provide nectar and pollen.
  • Use parasitic wasps such as Aphidius spp. and Diaeretiella rapae to attack leafhopper eggs and nymphs. These can be purchased from gardening stores or online and released in the garden.
  • Maintain a diverse ecosystem in your garden or landscape can help to control leafhopper infestations by providing natural predators and parasites with a variety of food sources.

Chemical Control

  • Use insecticides that are labeled for leafhopper control. Be sure to follow the instructions on the label carefully.
  • Use systemic insecticides that are taken up by the plant’s vascular system and provide long-term control.
  • Use contact insecticides to kill leafhoppers on contact but don’t provide long-term control.
  • Be sure to use the correct product for the specific type of plant you’re trying to protect.
  • Avoid using broad-spectrum pesticides as they can kill natural predators and parasites and disrupt the ecosystem.
  • Always read and follow the label directions for any pesticide you use.