Planthoppers

Planthoppers are not leafhoppers, though they have much in common. Most important, both spread disease as they siphon sap from plants.

Green coneheaded planthopper (xpda) CC BY-SA 4.0

Planthoppers as disease vectors

Planthoppers are responsible for transmitting several diseases, especially those caused by phytoplasmas and viruses. One planthopper species nearly wiped out Jamaican Tall coconuts by infecting trees with lethal yellowing. Planthoppers often transmit X disease to cherries and other stone fruits. They are also responsible for spreading cereal tillering disease, maize mosaic, and several other diseases.

Planthopper description

There are more than 12,500 planthopper species (Fulgoroidea), and they occur worldwide. With so many species, it’s no surprise that they come in several shapes, sizes, and colors. Spotted lanternflies and buffalo treehoppers are types of planthoppers. Snowy planthoppers look like whiteflies.

nthopper (Geoff Gallice) CC BY 2.0

'Fulgorid' planthopper (Geoff Gallice) CC BY 2.0

As their name indicates, these insects can launch themselves from one place to another. They do this the same way grasshoppers do. More often, however, they walk very slowly. But that’s not what makes them so hard to see.

Planthoppers often look like leaves or other plant parts. You can look right at one and not see it. Generally speaking, planthoppers hold their wings vertically, like butterflies, and their bodies are flattened. Nymphs produce a waxy substance that protects them from water and predators. Adult females also produce this wax and use it to protect their eggs.

Planthopper larvae (Richard Bartz) CC BY-SA 2.5

Planthopper diet

Planthoppers are sap suckers. As they feed on practically all of your garden plants, they produce a sugary poop called honeydew. Sooty mold thrives on honeydew. So do ants. In fact, ants are known to tend planthopper larvae, protecting them from predators. The larvae of some planthopper species live underground and feed on plant roots or fungi.
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Planthopper management

Planthoppers can be difficult to control because of their mobility. Many people recommend spraying them with a blast from the hose. I imagine this would take care of the nymphs who would be unable to return to their food supply, but I can’t imagine it would be very effective against adults. I could be wrong. Luckily, they are attracted to yellow sticky sheets. And predatory stink bugs feed on planthopper larvae.

Did you know that some planthopper species communicate with their neighbors through vibrations in plant stems? I didn’t either.