Leafhoppers and planthoppers
Click for larger image Close-up of candystripe leafhopper (Hemiptera) on coleus (Solenostemon); note, spines along hind tibia

Numerous species of leafhoppers and planthoppers are found in Missouri, and many of them have a broad host list (for example, the potato leafhopper, Empoasca fabae, has over 100 host plants). They feed on foliage and shoots of many different plant species by piercing the plant cells and sucking out the contents. The damage that results from feeding depends on the host plant and the specific hopper. Only a few species of hoppers transmit pathogens such as those that cause curly top virus and aster yellows. Adult hoppers are excellent short-distance jumpers when disturbed, and they can be pests when found in high numbers.

Symptoms and Diagnosis

Hoppers are agile insects that can move with equal ease either forwards, backwards, or sideways like a crab. The crab-like motion distinguishes hoppers from most other insects. In addition, they can hop to escape danger or to move to another host plant.

Feeding damage from some species causes small white spots (stippling) to appear on the upper leaf surface, usually beginning near the leaf midrib.

Stippled areas can unite into larger whitish blotches on mature leaves. With some plants, feeding damage causes a drying and yellowing (or browning) of leaf margins, and possibly the whole leaf. Some leafhopper species cause curling or stunting of terminal leaves with their feeding. Another sign of feeding is the presence of tiny varnish-like spots of excrement on the underside of leaves. Also, check under leaves for white, papery cast skins that remain from the molting process.

The lacebug is another insect that causes stippling from feeding and leaves dark droplets of varnish-like excrement on the underside of leaves. Distinguishing lacebugs from leafhoppers is easy:

Lacebugs have a lacy pattern on their upper side, they don't jump or run sideways, and they are about half as broad as they are long. Yet another pest that can cause stippling is the spider mite. Check under leaves for the webbing left by spider mites (leafhoppers don't leave webbing).

Life Cycle

Adults of most species of leafhopper range between 1/8 to 1/4 inch long. They are slender and frequently have an angular, pointed head. Coloration depends on species, but generally leafhoppers are shades of green, brown, or yellow and are often mottled. Nymphs (immatures) look similar to the adults except that the nymphs are smaller and don't have wings. Nymphs typically feed on the underside of leaves, where the humidity is higher and they are more protected from predators.

Leafhoppers have several generations each year. Some species migrate south in winter and return north with late spring weather.

Integrated Pest Management Strategies

1. Live with the pests. Because of their mobility and abundance, leafhoppers are not easy to control. However, leafhoppers are seldom present in large enough numbers to seriously injure plants. In addition, leafhoppers have many natural enemies, including lady beetles, lacewings, damsel bugs, and spiders. They are also subject to diseases and parasites that help keep their numbers down under most conditions.

2. Use row covers. Floating row covers or netting can be placed over plants early in summer to exclude leafhoppers. Remove row covers when the plants begin to flower.

3. Monitor with sticky traps. Many leafhoppers are attracted to yellow sticky traps which should be placed close to the foliage of the crop. Populations can be monitored with sticky traps and low populations can be managed using these traps.

4. Apply insecticidal soap. Insecticidal soap can control leafhoppers if applied when the insects are small. The immature leafhoppers are usually found on the underside of leaves so be sure to spray there also.

5. Apply insecticides. Other insecticides available for leafhopper control include botanical pyrethrinscarbaryl (Sevin), malathion, bifenthrin, cyfluthrin, bendiocarb (Turcam, Closure), disulfoton (Disyston), and acephate (Orthene). In general, these are most effective on the immature leafhoppers because they can't escape as well as the adults and are typically more susceptible to chemicals.

Organic Strategies

Strategies 1, 2, and 3 are strictly organic approaches. For an organic approach to Strategies 4 and 5, consult the Organic Materials Review Institute (OMRI™) for appropriate insecticidal soap and pyrethrin products.

More images:

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Adult green planthopper (Hemiptera)
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Adult leafhopper (Hemiptera)
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Adult green planthopper (Hemiptera) on canna (Canna)
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Leafhopper or planthopper larva/nymph (Hemiptera); note, wingbuds, large eyes, nearly invisible antennae, and enlarged hindlegs
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Side view of green planthopper (Hemiptera); note, wings held tentlike over body and indiscernible antennae
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Top view of green planthopper (Hemiptera); note teardrop shape
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Side view of white planthopper (Hemiptera)
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Top view of white planthopper (Hemiptera)
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White planthopper (Hemiptera)
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White filament on maple leaf (Acer) from a leafhopper or planthopper (Hemiptera)
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Close-up of white filament and cast skins on maple leaf (Acer) from a leafhopper or planthopper (Hemiptera)
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Treehoppers have a pointed pronotum making them resemble thorns on a stem
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Adult leafhopper (Hemiptera) on a Japanese maple leaf (Acer)
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Adult leafhopper (Hemiptera) on a Japanese maple leaf (Acer)
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Leafhopper larvae or nymph (Hemiptera); note wingbuds, big eyes, and threadlike antennae under the eyes
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Leafhopper larvae or nymph (Hemiptera) and typical feeding damage (stippling)
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Dictyopharid planthopper (Hemiptera), probably Rhynchomitra microrhina
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Sideview of dictyopharid planthopper (Hemiptera), probably Rhynchomitra microrhina
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Close-up of dictyopharid planthopper (Hemiptera), probably Rhynchomitra microrhina
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Treehopper with thorny pronotum (Hemiptera) laying eggs on black-eyed Susan ( Rudbeckia fulgida var. sullivantii 'Goldsturm' )
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Treehopper with thorny pronotum (Hemiptera) laying eggs on black-eyed Susan ( Rudbeckia fulgida var. sullivantii 'Goldsturm' )
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Leafhopper nymph (Hemiptera) on squash (Cucurbita) leaf
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Close-up of leafhopper nymph (Hemiptera) on squash (Cucurbita) leaf
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Leafhopper nymph (Hemiptera)
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Characteristic white filaments left behind by leafhoppers (Hemiptera)
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Scorch on honey locust (Gleditsia triacanthos) caused by leafhopper (Hemiptera) feeding, called hopper burn
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Scorch on honey locust (Gleditsia triacanthos) caused by leafhopper (Hemiptera) feeding, called hopper burn
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Molted skin of a leafhopper (Hemiptera) and the white filaments that leafhoppers exude on the underside of a hydrangea leaf (Hydrangea)
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Stunted and deformed leaflets on thornless honey locust (Gleditsia triacanthos) are characteristic of the feeding of certain plant bugs (Hemiptera ) and leafhoppers (Hemiptera)
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Close-up of stunted and deformed leaflets on thornless honey locust (Gleditsia triacanthos) probably caused by the feeding of certain plant bugs (Hemiptera ) or leafhoppers (Hemiptera)
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The damage on this silver maple leaf (Acer saccharinum) is typical of feeding by leafhoppers (Hemiptera) but it could be caused by a true bug
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Stippling on silver maple leaves due to feeding by leafhoppers (Hemiptera) or true bugs; galls, possibly maple bladder galls caused by an eriophyid mite, are also present
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Even if absent, the presence of leafhoppers (Hemiptera) can be deduced from the white, waxy material they sometimes leave behind, as on these hackberry leaves (Celtis)
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Leafhopper adult (Hemiptera) on squash (Cucurbita)
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Candystripe leafhopper (Hemiptera) on coleus (Solenostemon)
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Leafhopper (Hemiptera) on culinary sage (Salvia officinalis)

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Thorn tree hoppers (Hemiptera) from Florida