Leafhopper
Emergence (est.) ActiveCicadellidae
51 host plants
Last updated
Leafhoppers are small (0.1 to 0.3 inch), wedge-shaped insects that congregate on the undersides of leaves, feeding by piercing plant tissue and sucking sap. Feeding damage causes stippled, yellowed patches on leaves visible on the upper surface. Common on fruit trees and ornamentals, they can cause significant aesthetic impact and occasionally transmit plant diseases.
Monitor ornamental and fruit tree foliage starting in May by examining leaf undersides and checking upper surfaces for stipple. For light populations, a strong water spray dislodges insects. Apply insecticidal soap or horticultural oil targeting insects; repeat every 7 to 10 days. Neem oil applied to undersides can be effective. Maintain plant vigor through appropriate watering.
Quick Reference
Leafhopper Emergence (est.) typically begins around 2291 GDD₃₂. As of June 3, 2026, all seven Puget Sound stations have passed this threshold (2435.5–2672.8 GDD₃₂), so Emergence (est.) is likely underway across the lowlands.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of Jun 3, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,673 | Emergence (est.) | — | — |
| Kent / Auburn | 2,665 | Emergence (est.) | — | — |
| Seattle / UW | 2,610 | Emergence (est.) | — | — |
| Olympia / Tumwater | 2,570 | Emergence (est.) | — | — |
| Tacoma / Puyallup | 2,535 | Emergence (est.) | — | — |
| Bellingham / Whatcom | 2,533 | Emergence (est.) | — | — |
| Sequim / Rain Shadow | 2,436 | Emergence (est.) | — | — |
GDD source: UMD IPMnet Pest Predictive Calendar (Gill & Klick). Base 50°F, mid-Atlantic climate. Converted to GDD₃₂ for Western WA. About GDD₃₂ →
Leafhoppers are slender, delicate insects about 0.125 inch or less in length. They are distinguishable from other pests due to the habit of the adult hopping or flying to escape danger, and by the ability of nymphs and adults to run forwards, backwards, or sideways easily. Several species of leafhoppers are found in cherry orchards, which vary in coloration from green to brown. Leafhoppers suck juices from the leaves of cherries, ornamental plants and weeds. Certain species of leafhoppers are...
Cultural Controls
- -cultural control Control weeds and alternative hosts such as, clovers, mallow, dandelion, curly dock, bitter cherry, and chokecherry, in and around your orchard.
- Management-
Host Plants (51)
Sources & References
Primary: PNW Insect Management Handbook