Spot Them Early
If you had a problem with leafhoppers last year, then you will likely have them around again, and it is important to spot them early so they don't build up their population. They are attracted to yellow sticky traps. Place two or three in the vicinity of the vulnerable plants at the same level as the plants. When you see just one or two, then check the plants on the undersides of the leaves. If you see more, then it is time to take some action.
Using No Insecticides
If you move quickly, you can crush nymphs between your thumb and forefinger before they move away.
Netting or Fleece Barrier - You want to prevent the leafhopper's access to the vulnerable plants. Nylon netting, fine screening, or agricultural fleece are all effective barriers, preventing leafhoppers from laying eggs at the plant's stem. Use floating covers that rest directly on plants, or create tunnels supported by braces. Set up the barrier immediately after planting to prevent any leafhoppers from infecting the plants. Seal all the edges to the ground.
Try Natural Insect Repellent Sprays
There are a number of botanic repellent sprays available for use against Leafhoppers and many other pest insects. These products both kill and/or repel. Leafhoppers doused with these sprays either die or move. New Leafhoppers coming along avoid the area with the repellent spray for several days to a few weeks. Go to the section in Yardener's Tool Shed called Natural Insect Repellents.
Using Natural Insecticides
There are a number of effective natural insecticides made from materials such as chrysanthemum blossoms (pyrethrum), neem oil soap, or light horticultural oil. These products are found in many independent garden centers, and are labeled for controlling Leafhoppers. There is detailed information about each product in Yardener’s Tool Shed in the section for Natural Insecticides.
Use Synthetic Pyrethroid Insecticides
An effective method for killing Leafhoppers is to spray them with a pyrethroid insecticides such as resmethrin or permethrin. These products are found in many independent garden centers, and are labeled by the EPA for controlling Leafhoppers. There is detailed information about each product in Yardener’s Tool Shed in the section Synthetic Insecticides.