Leafhoppers are found on plants all over the world and are from the Cicadellidae family. The insect is attracted to forests, agricultural fields, deserts, home gardens, and nearly everything in between. There are more than 12,000 species of leafhoppers.
Due to the wide variety of species, numerous types of vegetation and plants are often attacked. This includes cannabis, fruits, vegetables, shrubs and turf grasses. There are a lot of different colors of leafhoppers, with the most common of these pests including the Glasshouse, Beet Leaf, Potato Leaf, Grape Leaf, Six-Spotted Leaf and Rose Leaf. Certain species of leafhoppers will only consume plants within the same family, while others attack a much larger variety of both plants and trees.
Leafhoppers are named for their amazing ability to jump long distances. When disturbed or stalked by a predator, their jumping ability often allows the insects to escape. Certain species can transmit pathogens, resulting in different plant diseases. There are usually several generations of leafhoppers born every year.
How do you identify leafhoppers? Leafhoppers can be identified by their extreme agility. They can move forward or backward very easily. Sometimes the pest moves from side to side, just like a crab. The crab-like movements are one of the best ways to tell leafhoppers apart from most other insects, as very few insects can move in the same way.
The modification of the hind legs is what enables leafhoppers to jump and move sideways. Their legs are also covered with hair that enables them to spread a secretion throughout their entire body. In addition to carrying pheromones, this secretion is a water repellant.
Leafhopper nymphs resemble adults, but they do not have wings, and are much smaller in size. Once reaching the adult stage, leafhoppers are between one-eighth and one-quarter inches in length. The body is slender, and in the shape of a wedge.
The spines of leafhoppers are distinctive due to the length and hind legs. The majority have a weak spine, and the keels in the rear are distinctive due to their movable spines.
There is a significant difference in coloration among the different leafhopper species. Some are a plain green, enabling the insects to blend with plants extremely well. Other species are easy to spot due to their patterns and coloration.
A portion of leafhopper antennae is thicker, extremely short, and has an arista or a bristle on the end. Their simple eyes have two ocelli and are placed at either the front or the top of the head. There are three segments to the small bones of the insect.
Leafhoppers are unique due to brochosome production. This is believed to not only provide the insects with protection, but their egg clutches as well. Leafhoppers are protected from both pathogens and predators because of this protection.
One of the most common species of leafhopper is the potato leafhopper. This pest will attack more than 100 different types of plants including cannabis, apples, beans and potatoes. Within certain areas, potato leafhoppers also attack fruit trees.
Another common species of leafhopper is the rose leafhopper. The main targets are in the Rosaceae or Rose families such as raspberries, blackberries and cranberries. This species will not consume fruit, but crawl over it to suck on the leaves leaving a foul trail of black excrement behind.
Rose leafhoppers use the stems of both cranberries and roses to lay their eggs because the thorns provide a good defense against predators. The adult females lay their eggs in the stems, where they remain throughout the winter. The eggs will not hatch until the spring. This species consumes the foliage of the plants.
The six-spotted leafhopper species is also referred to as aster. The main food sources are vegetables and annual flowers. This species injures plants in two different ways. The cell sap is removed causing a disturbance in photosynthesis leading to aster yellows disease.
The aster leafhopper is the most common carrier of this disease. The symptoms are different for each plant including stunted growth, yellowing of the leaves and deformities within the structure. There are hundreds of plants this insect will attack including tomatoes, marigolds and daisies.
The Life Cycle of Leafhoppers
The metamorphosis occurring during development is incomplete for leafhoppers. The females insert extremely small eggs directly into the tender tissue of the plants, resulting in injuries resembling pimples. The eggs remain in the tissue during the winter months, then hatch during the middle of April. The nymphs emerge without wings, then molt between four and five times prior to maturing into adults.
Leafhopper nymphs mature into adults in approximately two to seven weeks. During the end of this stage, the nymphs develop little wing pads. Leafhoppers do not have a pupal stage. Many eggs remain on twigs or in plant stems during the winter, with the adults seeking areas offering protection including the crevices in the bark. In areas with a cold climate during the winter, leafhoppers often die.
During the spring, leafhoppers from warmer climates will migrate back to these areas producing a minimum of two generations every year.
What Does Leafhopper Damage Look Like?
Leafhopper plant damage is dependent on the specific species, but includes:
- Sticky substance (honeydew) on the leaves
- Growth of black and sooty mold
- Skin from molting
- Little black spots of excrement on the leaves
- White spots or stippling on leaves
- Yellow, brown or dry leaf tips (aka hopper burn)
The most obvious sign that leafhoppers are present is honeydew. Once the insect has consumed the plant, honeydew is secreted, and this substance is left on the leaves. Honeydew looks like tiny spots of tar and will attract ants. Honeydew can also result in foliage being blackened by the growth of sooty mold.
Several other pests secrete honeydew so you will need to be sure to examine those that are visible to determine if they are leafhoppers.
In most instances, nymphs attack the underside of the leaf. Look for leafhopper damage including tiny black excrement spots and skins left behind after molting. Leafhopper damage is different, depending on the plant and insect species. When under attack by leafhoppers, plants may be unable to produce flowers.
The presence of leafhoppers seems innocent but when the population is large enough, plants often sustain severe damage caused by the spreading of diseases or feeding. When feeding, the sap is siphoned out of the foliage resulting in white stippling appearing on the leaves due to a lack of green chlorophyll. Plant leaves can also display symptoms of what is referred to as “hopper burn.” When hopper burn is present, leaf tips will turn yellow and in extreme cases, brown.
Once generations of leafhoppers begin to multiply, damage increases significantly. Taking steps necessary to prevent an infestation is extremely important. During certain life stages, these pests will attack cannabis, roses, potatoes, grapes and apples in certain states. No matter what stage the pest is in, it will feed on the sap contained in the leaves.
The white stippling that occurs resembles that of a spider mite which is why it is always important to identify the pest. When a leafhopper infestation is larger, plants appear unattractive due to noticeable dark excrement. The damage intensifies if the leafhoppers transport bacteria between the plants. This occurs frequently in numerous species of trees including sycamore, maple, oak and elm, leading to leaf scorching.
How to Get Rid of or Kill Leafhoppers Naturally
There are four basic ways to get rid of leafhoppers naturally including:
- Natural predators
- Row covers
- Sticky traps
Natural predators are a good option including leafhopper assassin bugs, minute pirate bugs, lacewings, lady beetles and spiders. Unless the numbers of leafhoppers are high, there is usually no serious risk to plants. Leafhopper numbers can be low or remain contained to natural parasites and predators.
When there is an infestation, netting or row covers can be used to cover the plants towards the beginning of the summer. This will prevent leafhoppers from attacking the plants. Once the plants start to flower, the row covers are simply removed. Sticky traps are often used to contain leafhoppers. Yellow traps are attractive to them and need to be set near the foliage of the plants.
These traps are useful for the management of leafhoppers, or to help monitor the current population.
How to Control Leafhoppers Naturally
There are a lot of good options to control leafhoppers naturally including:
- Apply Trifecta Crop Control as a preventative
- Reflective mulch
- Spray plants with water
- Sprinkling with kaolin clay or diatomaceous earth
- Remove plant debris and weeds
- Do not overwater plants
Leafhoppers do not like garlic so applying Trifecta Crop Control as a preventative will keep them at bay.
- .5oz per gallon applied once per week during veg
- 1oz per gallon applied once per week during flower up to 2 weeks before harvest
When the plants are developing or growing, reflective mulch can be an effective deterrent. Reflective mulches provide many positive advantages for farmers, such as increased yields, early maturing crops, high quality crops, enhanced insect management, and weed control. Leafhoppers become confused by the reflective mulch, discouraging them from feeding on the plants.
For smaller gardens and sturdy, non-cannabis plants, you can use a strong stream of water to spray and remove them from your plants.
Sprinkling Kaolin clay or diatomaceous earth give may provide partial control when nymphs are small. Coat plants and soil surrounding the plant with a thin coating. Diatomaceous earth can be dangerous if inhaled so take caution when applying and be sure not to breathe in the fine dust.
Make certain any plant debris is removed from the garden to eliminate potential shelters. All weeds need to be removed including wild mustard. Any plants showing symptoms of beet curly top or aster yellows disease should be removed prior to the winter months.