Leafhoppers

Boing! A tiny insect launches itself and you never really see it clearly.

​It’s probably a leafhopper. Let’s learn about these garden pests so we can reduce the damage they cause.

Leafhopper (631372) Pixabay

Leafhopper lifecycle

Leafhoppers are cousins to treehoppers and cicadas. The name “leafhopper” actually refers to twenty thousand different Cicadellidae insects. Most leafhoppers feed on a specific plant or group of plants. Eggs are laid in soft plant tissue, where they overwinter. Eggs begin to hatch in mid-April in warmer regions. These wingless nymphs will molt several times, each time their wings and hind legs getting larger and more functional. What makes leafhoppers particularly unique is that they cover themselves, after each molt, with a microscopic body armor made out of netted spheres called brochosomes. [It's one of those 'stranger than fiction' realities, isn't it?]

Glassy-winged sharpshooter carries masses of brochosomes (the white spot) to be used during egg-laying. (Alex Wild, Insects Unlocked) Public Domain

This armor keeps them dry and protects them from their own sugary excrement. Brochosomes are also believed to protect them from enemies, as well, but no one is really sure. What I am sure of is that leafhoppers are unwelcome in my garden and landscape, and here’s why:

​​Leafhoppers eat sap and, as they feed, they spread disease.

​Plants preferred by leafhoppers

Common brochosomes (Roman Rakitov) CC0

Leafhoppers enjoy many of the same plants that we do. In addition to many woody ornamentals,  such as boxwood, local leafhopper species love to feed on sweet potatoes, squash, beans, horseradish, cucumbers, corn, melons, blueberries, grapes, and beets, just to name a few! Since leafhoppers can carry diseases with them, they put many plants at risk.

Small green leafhopper (Jean and Fred) CC BY 2.0

Leafhopper damage

Leaf stippling is usually the first sign of leafhopper infestations. This damage is normally at its worst during the hottest months. While leaf stippling won’t harm a healthy plant, it does interfere with photosynthesis and it can compound water stress. Leaves may also appear pale or brown, and new shoots may curl up and die. As they feed, some leafhopper species produce honeydew, which provides the perfect growing medium for sooty mold. Also, leafhoppers are vectors for several plant diseases, including aster yellows, bean mosaic, and vivipary.

Leafhopper stoppers

Since they are so mobile, complete control is pretty much impossible. Spiders, assassin bugs, and lacewings all eat leafhoppers, so avoid using broad spectrum pesticides that will kill off these beneficial insects. Severe infestations can be treated with insecticidal soap or horticultural oil, just be judicious with the application since oils can contribute to sunburn damage. These treatments are only effective on nymphs.

So, if you walk by a plant and get pelted by a bunch of tiny bugs, or you notice a lot of leaf stippling, take a closer look - it may be time for insecticidal soap.