Green leafhoppers are small, common insects found in various regions that can affect a wide range of plants. These pests are known for their vibrant green color and their ability to move quickly across plant surfaces. Their presence can lead to noticeable issues for gardeners and growers. Understanding their characteristics and behaviors is important for managing their impact on plant health.
Identifying the Green Leafhopper
Adult green leafhoppers are typically small, measuring about 3 to 5 millimeters in length. They possess a distinctive bright green color and a slender, wedge-shaped body. These insects are quite agile, often moving with a characteristic diagonal scuttling motion or jumping readily when disturbed. They are commonly found on the undersides of leaves or on tender green shoots of various host plants. When at rest, green leafhoppers often hold their wings in a roof-like manner over their bodies, sometimes at a slight angle.
The Life Cycle
The green leafhopper undergoes an incomplete metamorphosis, progressing through three main stages: egg, nymph, and adult. Female leafhoppers typically lay their tiny, pale eggs within the tissue of plant leaves, such as the midribs or leaf sheaths. These eggs usually hatch within 6 to 8 days.
Nymphs emerge resembling smaller, wingless versions of the adults, initially appearing yellowish-white before gradually turning green as they develop. They undergo five growth stages, or instars, over a period of 18 to 30 days. Adult leafhoppers can live for approximately 20 to 30 days, and depending on climate, there can be one to six generations per year.
Damage to Plants
Green leafhoppers can cause damage to plants through direct feeding and by transmitting various plant diseases. Both nymphs and adults use piercing-sucking mouthparts to extract sap from plant tissues. This feeding can lead to symptoms such as pale specks, known as stippling, and a general yellowing of leaves. Severe infestations can result in leaf curling, stunted growth, wilting, and a condition called “hopperburn,” where foliage turns yellow, then brown, and dies.
Beyond direct feeding, green leafhoppers are significant vectors for plant pathogens, including certain phytoplasmas and viruses. They acquire these pathogens while feeding on infected plants and then transmit them to healthy ones during subsequent feeding. Examples of diseases spread by leafhoppers include rice tungro virus and aster yellows, a phytoplasma disease causing yellowing, dwarfing, and distorted foliage. Other viral diseases like curly top virus are also transmitted by specific leafhopper species.
Controlling Green Leafhoppers
Managing green leafhopper populations involves a combination of strategies to reduce their numbers.
Cultural Practices
Cultural practices can significantly deter leafhoppers and support plant resilience. These methods include removing weeds that serve as alternative hosts for the insects, maintaining proper plant health, and using resistant plant varieties. Employing reflective mulches, such as aluminum foil, around plants can confuse leafhoppers and discourage them from landing. Row covers can act as a physical barrier to exclude the insects.
Physical Removal
Physical removal methods are effective for smaller infestations. A strong spray of water can dislodge nymphs and adults. Light traps can attract and capture adult leafhoppers, while yellow sticky traps monitor their presence.
Biological Control
Biological control utilizes the leafhoppers’ natural enemies. Various predatory insects, such as mirid bugs, lacewings, lady beetles, assassin bugs, and spiders, prey on leafhoppers. Parasitic wasps, particularly egg parasitoids like Anagrus species, lay their eggs inside leafhopper eggs, preventing them from developing. Encouraging these beneficial insects by planting nectar and pollen-rich flowers can enhance their presence in the garden.
Chemical Controls
For more severe infestations, certain chemical controls can be considered. Insecticidal soaps and horticultural oils can be applied to directly target leafhoppers. When using any chemical product, it is crucial to carefully follow label instructions.
Integrating these diverse approaches—cultural, physical, biological, and chemical—provides a comprehensive strategy for effective green leafhopper management.