Leafhopper Damage: All You Need to Know for Healthy Plants

Leafhoppers are a diverse group of hopping insects known for causing damage to various plant species by piercing and sucking sap from plant tissues. These insects are often identified by their small size, wedge-shaped bodies, and rows of spines on their hind legs ¹. While some species are known for their striking colors, like the red-banded leafhopper, others can be light-colored or brown, depending on the plant they infest ².

These tiny pests can lead to a type of injury known as “hopper burn” which shows up as a yellowing of the leaf margins, followed by curling and necrosis [^3^]. Hopper burn is caused by toxins in leafhopper saliva blocking plant veins during feeding. This damage can lead to reduced plant yield, limiting the growth and productivity of the plant species affected. In this article, we’ll discuss all you need to know about leafhopper damage, prevention, and control methods.

Leafhopper Basics

Identification and Features

Leafhoppers are small, wedge-shaped insects with variable colors, often light or brown. Some of them, like the redbanded leafhopper, have bright red and blue (or green) markings on their wings and thorax. Their size is typically less than 1/6-inch, and they possess:

• A distinctive head, legs, and underparts, often bright yellow
• Thin wings
• A slightly wedge-like shape

Life Cycle

The life cycle of leafhoppers consists of two main stages: nymphs and adults. The nymphs are wingless and develop through several molts to reach the adult stage. Adults are the flying stage in leafhoppers’ life cycle, featuring functional wings.

Habitats

Leafhoppers can be found worldwide and are common in various habitats, including:

• Lawns
• Vegetables and fruit crops like potatoes, eggplants, and raspberries
• Ornamental plants

Comparison Table: Nymphs vs. Adults

Types of Leafhoppers and Host Plants

Common Leafhopper Species

There are numerous leafhopper species, but some commonly found ones include:

• Glassy-winged sharpshooter: These leafhoppers transmit the bacterial pathogen Xylella fastidiosa, causing various plant diseases¹.
• Blue-green sharpshooter: Similar to glassy-winged sharpshooters, these leafhoppers are also vectors of Xylella fastidiosa¹.
• Potato leafhopper: Known to feed on nearly 200 types of plants, these leafhoppers can cause damage to crops in northern areas².

Affected Plants and Crops

Leafhoppers cause damage to a wide variety of different plants, including:

• Fruit: apples, grapes
• Vegetables: potatoes, beans, corn
• Other crops: alfalfa, ornamentals
• Flowers: roses

Comparison of Common Leafhopper Species and their Host Plants

Pros of leafhoppers’ ecosystem function:

• Serve as a food source for other insects

Cons of leafhoppers:

• Damage plants by feeding on sap
• Transmit harmful pathogens, like Xylella fastidiosa

While leafhoppers can cause damage to various crops and plants, in some cases, they can also serve as a food source for other insects, contributing to the ecosystem’s balance.

Leafhopper Damage to Plants

Visible Signs of Damage

• Yellowing: Leafhoppers suck sap from plants, causing leaves to yellow and wilt.
• Stippled appearance: Their feeding leads to tiny white or yellow spots on leaves.
• Leaf curl: As damage progresses, leaves may curl and develop a “scorched” appearance.

For example, the potato leafhopper can cause damage to potato, bean, and other food crop leaves.

Effects on Plant Growth and Health

• Stunted growth: Leafhopper feeding affects the nutrient supply, leading to reduced plant growth.
• Weakened plants: Affected plants are more susceptible to diseases and other pests.

For instance, the aster leafhopper can spread aster yellows disease, which further weakens plants and is untreatable.

Comparison of Leafhopper Damage Signs

Remember to monitor your plants regularly to detect leafhopper damage early and take appropriate measures to control them.

Diseases and Pests Associated with Leafhoppers

Disease Transmission

Leafhoppers are known for transmitting plant diseases, particularly bacterial pathogens like Xylella fastidiosa. This bacterium can cause various diseases in different plant hosts. For example, aster yellows is a phytoplasma disease spread by the aster leafhopper that affects carrots, celery, lettuce, potatoes, and other vegetables by causing yellowing, dwarfing, and distorted foliage (source).

Pest Interactions and Collaboration

Leafhoppers often interact with other pests in their environment. They produce honeydew, a sweet, sticky substance that attracts ants and promotes the growth of mold.

Some common pests associated with leafhoppers include:

• Ants
• Spider mites
• Aphids

These pests can work together with leafhoppers, making infestations more challenging to manage.

Pros and Cons of leafhoppers

Pros:

• Assist in pollination
• Can be a food source for beneficial insects

Cons:

• Damage plants directly by feeding on sap
• Transmit diseases to plants
• Attract other pests with honeydew

Natural Enemies of Leafhoppers

Leafhoppers have natural enemies that help control their populations. Some of these predators include:

• Pirate bugs
• Lady beetles
• Lacewings
• Parasitic wasps

For example, Anagrus erythroneurae and A. daanei egg parasites can control leafhopper populations effectively in vineyards (source).

By understanding the diseases and pests associated with leafhoppers, it becomes easier to manage their impact on plants and incorporate favorable control methods.

Monitoring and Controlling Leafhopper Populations

Prevention Strategies

• Regular inspection of plants for early signs of leafhopper infestation
• Removing plant debris to eliminate overwintering sites
• Encouraging natural predators like ladybugs and lacewings
• Avoiding excessive use of nitrogen fertilizers, which can attract leafhoppers

Organic and Chemical Control Methods

Organic Control Methods

1. Neem oil: A natural pesticide effective in controlling leafhopper populations
   • Pros: Safe for beneficial insects, biodegradable
   • Cons: May need frequent application, can be harmful to aquatic life
2. Diatomaceous earth: A powder made from fossilized algae, lethal to leafhoppers
   • Pros: Inexpensive, safe for beneficial insects
   • Cons: Ineffective when wet, may need reapplication after rain or irrigation
3. Insecticidal soap: Potassium salts of fatty acids used to weaken and kill leafhoppers
   • Pros: Environmentally friendly, safe for most beneficial insects
   • Cons: Direct contact required, may require multiple applications

Chemical Control Methods

1. Pesticides: Synthetic chemicals used to control leafhopper infestations
   • Examples: Pyrethrins, malathion, carbaryl
   • Pros: Quick and effective control
   • Cons: Harmful to beneficial insects, may promote pesticide resistance

Promoting Beneficial Insects and Natural Predators

Types of Beneficial Insects and Predators

Some examples of beneficial insects and predators in your garden are:

• Ladybugs
  • Consume aphids, mites, and other pests
  • Red or orange with black spots
• Lacewings
  • Predatory in both adult and larval stages
  • Feed on aphids, mites, whiteflies, and more
• Spiders
  • Non-insect predators
  • Help control various pests
• Other Predatory Insects
  • Includes ground beetles, assassin bugs, parasitic wasps

By promoting these beneficial insects and natural predators, you can naturally control leafhopper populations.

Attracting and Encouraging Their Presence

Below are some ways to attract and encourage beneficial insects and predators:

• Plant a variety of flowering plants
  • Examples: dill, parsley, cilantro, Queen Anne’s lace
• Provide habitats such as shrubs, hedges, and mulch
• Avoid using broad-spectrum insecticides
• Practice proper watering and pruning methods

By following these tips, you can create a healthy garden ecosystem, providing both a beautiful space and effective biological control against leafhoppers and other pests.

Managing Leafhoppers in the Garden

Minimizing Habitat and Breeding Sites

• Keep your garden clean of weeds and debris, as these can provide leafhoppers with hiding spots and breeding sites
• Prune and maintain both garden plants and ornamental plants, to discourage leafhoppers from laying eggs

Leafhoppers usually feed on various garden plants and are attracted to an unkempt garden. Keeping your garden area free of weeds, and properly maintaining plants can help minimize their habitat and breeding sites.

Implementing Barriers and Protective Measures

• Use floating row covers during the growing season to protect plants
• Consider including plant species that attract beneficial insects, which prey on leafhoppers
• Regularly check host plants for signs of leafhopper infestations

Utilizing barriers like floating row covers can help protect your garden from leafhoppers during the growing season. Growing plants that attract beneficial insects, such as pollinators, also aids in controlling the leafhopper population. Regularly checking your plants for symptoms of infestation and acting promptly can prevent widespread damage to your garden.

By effectively managing leafhoppers in your garden using these techniques, you can maintain the health and beauty of your plants.

Professional Pest Control and Support

When to Consult Professionals

It’s essential to consult professionals when:

• Leafhoppers cause extensive damage to your plants
• You’re unable to identify the pest
• DIY pest control methods are ineffective

For example, if your plants have severe hopper burn and self-management efforts aren’t helping, a professional can better assess the situation and provide guidance.

Available Resources

Online resources can be valuable, such as the UC Statewide IPM Program, which offers information about leafhopper species and management approaches.

Comparison Table for Online Resources:

Expert Advice

Professionals can:

• Help identify the specific leafhopper species causing damage
• Recommend tailored Integrated Pest Management (IPM) strategies
• Advise on preventive measures and monitoring tactics

For example, a professional may suggest regularly checking your crop’s action threshold to determine whether leafhopper numbers warrant control action.