Rose stem girdler
Agrilus cuprescens
4 host plants
Last updated
Look for insect creates sinuous, serpentine mines across the undersides of rose leaves and stem tissue, visible as irregular white chain-like blisters containing legless larvae. Where mining cuts through leaf veins, the distal portion of the leaf may fade in color. The characteristic damage is easily spotted on foliage and is primarily cosmetic on healthy roses.
Remove and discard affected foliage to prevent infestation cycles. Maintain plant vigor through proper care to support recovery. This pest rarely causes serious health impacts, so tolerating minor mines is acceptable. Pruning infested leaves is the most practical management approach.
Quick Reference
The rose stem girdler is a flat-headed, wood-boring beetle that is about 6 mm (~1⁄4") long. When it is young, it is black with a coppery red/bronze thorax. Later, the beetles are dark copper to greenish copper. The larvae are cream-colored. When the primocanes start to bloom, the larvae can be found feeding just below the bark. This feeding girdles the canes. Swollen stem galls are seen on some varieties. The girdling from this insect pest may cause the primocanes to die. If the canes are not killed, the next season's floricanes may not produce much fruit. The feeding damage weakens the canes
Cultural Controls
- -cultural and
This pest is relatively new to the PNW. Damage is increasingly being reported throughout the south Puget Sound basin. It has been confirmed in Snohomish, Skagit, and Whatcom counties in Washington since 2022, indicating active spread in this region.