Leafhoppers (Cicadellidae) are a group of true bugs; sometimes they're called hoppers. They're small insects; feeding by piercing plant foliage with their specialised mouthparts. Most drink plant sap, but a fraction of species are known to eat small soft-bodied insects, like aphids. Because most species are strictly vegetarian, they're pests of ornamental, edible and herbaceous plants. Some of the symptoms they produce in plants include mottled leaf surfaces, curling foliage, honeydew secretions, typically followed by an accumulation of black sooty mould. In most cases, one or two hoppers on your plant won't do too much harm. In rare cases, some can transmit pathogens from plant to plant, which may cause other symptoms to arise.
Leafhoppers are a vital food resource for predatory insects, like ladybirds!
Due to their fine filament feeding tubes, these insects are capable of spreading plant diseases.
These insects undergo a type of development which involves a series of moults. With every moult, the insect grows larger in size and is one step closer to adulthood! Adults: Mature insects are wedge-shaped, with the heads being the broadest, the tail end narrower in width. The eyes are typically large and bulbous; they're often compared to a frog, which is why they're frequently confused with froghoppers. Many species demonstrate impressive colouration- sporting vivid shades of green, yellow, red and blue. Nonetheless, they can also be drab in colour so that they can blend into the environment. Nymphs: Juvenile insects are typically smaller than adults; they also lack the vivid colouration and comprise just one pale colour. Eggs: Dependent on species. Eggs are injected into plant tissue so often go unnoticed by gardeners. Tip: Distinguish froghoppers (Superfamily: Cercopoidea) from leafhoppers (Family: Cicadellidae) using the hind legs. A leafhopper will have 1 to 3 rows of fine, thin, spines, whereas; a froghopper possesses two wide and thick spines on the outer edge of the hindleg.
Leaf mottling Leaf curling Leaf yellowing Honey dew on foliage Black sooty mould on leaves Small, jumping insects leaping off the leaves when disturbed Casts from moults sometimes evident beneath the leaves
Leafhoppers are a food resource for spiders, parasitic wasps and small insect-eating birds, so attracting these to your garden will limit the damage caused by these bugs. This can be done by planting pollinator-friendly flowers, hanging baskets or installing climbers, or incorporating some form of habitat/ insect hotel in the garden. Please research insect hotels carefully, as many that are commercially-bought can do more harm than good. Neem oil applied to plants are sucked up with plant sap, and incorporated into the digestive system. From here, it interferes with the insects' growth and reproduction, ending in death! Neem oil should only be applied during cool periods of the day.
In most cases, leafhoppers won't cause significant damage. However, some species can be problematic. If a chemical treatment is sought, please check with your local regulating body for guidance on active ingredients and their authorisation for use. Plants that are in flower should never be sprayed due to the dangers they pose to pollinators. There are an array of contact insecticides available for use on the market that is more environmentally friendly than the above products (e.g. Natural pyrethrum/pyrethrins and insecticidal soaps). Persistent products include synthetic insecticides with a contact mode of action (e.g. cypermethrin, phenothrin, lambda-cyhalothrin and deltamethrin). These can still be toxic to some wildlife and a pollutant to water bodies, so please take care to research products and read instructions carefully before using them.
Some species diets are broad, so they're not particularly choosy on what's for lunch. Others possess diets more specialised, limiting them to only one or two plants.
They're also heavily predated by spiders and parasitoid wasps and flies.