Strawberry crown moth
Emergence (est.) ActiveSynanthedon bibionipennis
1 host plant
Last updated
Strawberry crown moth larvae tunnel into the crowns and roots of strawberry plants and certain woody hosts. Look for wilting or dying crowns, sawdust-like frass at the base of plants, and small entrance holes. Host records list Mediterranean plants like strawberry tree (Arbutus unedo).
Monitor plant crowns regularly for signs of larval activity. Remove and destroy infested plants to prevent spread. Since this pest is uncommon in many regions, no large-scale control strategy is standard. Maintain healthy plant vigor to support recovery from minor infestations. Avoid moving infested stock between plantings.
Quick Reference
Strawberry crown moth Emergence (est.) typically begins around 1778 GDD₃₂. As of May 14, 2026, all seven Puget Sound stations have passed this threshold (1926.1–2121.1 GDD₃₂), so Emergence (est.) is likely underway across the lowlands.
Regional Season Tracker
GDD₃₂ accumulation across 7 Puget Sound stations · as of May 14, 2026| Station | GDD₃₂ | Current Stage | Next | To Go |
|---|---|---|---|---|
| Issaquah / East King | 2,121 | Emergence (est.) | — | — |
| Kent / Auburn | 2,113 | Emergence (est.) | — | — |
| Seattle / UW | 2,085 | Emergence (est.) | — | — |
| Olympia / Tumwater | 2,047 | Emergence (est.) | — | — |
| Tacoma / Puyallup | 2,016 | Emergence (est.) | — | — |
| Bellingham / Whatcom | 1,994 | Emergence (est.) | — | — |
| Sequim / Rain Shadow | 1,926 | Emergence (est.) | — | — |
Source: Pest GDD Catalog, UMD IPMnet. Adult emergence at 468 GDD₅₀ from genus-level Synanthedon spp. models. No species-specific GDD model published for S. bibionipennis. PNW Handbooks confirm adults emerge June-July in PNW (consistent with 468 GDD₅₀ timing). Best available estimate. Added 2026-04-03. About GDD₃₂ →
The strawberry crown moth is an insect native to the PNW and has caused damage to strawberries in the northern Willamette Valley. The adult strongly resembles a yellow jacket; it is about 12 to 15 mm in length, black with yellow markings. The eggs are brown, oval, sculpted on the surface, and distinctly cupped on the sides. The larvae are white with a brown head, and 16 to 25 mm in length at maturity. Larvae feed on the crown and root tissue of the strawberry plant. This feeding provides entry...
Cultural Controls
- -cultural control No commercial strawberry varieties resistant to SCM are available.
- Untopped strawberry plants can serve as trap plants.
- If plants are topped before the moth's flight period, a few rows should be left untopped.
- Egg-laying females are attracted to and deposit a significant portion of their eggs on the untopped plants.
- These untopped plants are then disked under in the fall.
- Remove infested plants.
Host Plants (1)
Sources & References
Primary: PNW Insect Management Handbook