Pest profile

Raspberry Horntail

Hartigia cressoni (iNaturalist genus: Phylloecus) · Hymenoptera: Cephidae[3]

Raspberry horntail larvae feed inside rose stems, making cane tips wilt and die in spring and reducing second-cycle blooms.[1]

No licensed photo of this species is available yet; the identification notes below describe what to look for.

How to identify it

  • Larvae are white and segmented, up to 1 inch long, and live inside stems or canes.[1]
  • Adults are black or black-and-yellow wood wasps about 1/2 inch long.[1]

Look-alikes

Look-alikeHow to tell them apart
Rose curculioA snout weevil that drills holes in buds rather than tunneling inside canes.[1]

Where it lives

UC IPM covers it among the insects that attack roses in California gardens.[1]

Biology and life cycle

Females make egg-laying incisions in canes, and larval feeding inside causes visible swellings.[1]

Damage and signs

  • Wilted, dying cane tips in spring reduce the second cycle of rose blooms.[1]

Health risk

It feeds on plants; UC IPM mentions no risk to people.[1]

Control

Sanitation

From mid-April to mid-June, check canes for egg-laying cuts or swellings and cut them off below the infestation.[1]

Traps and physical control

Prune infested canes back until you reach a healthy cross section.[1]

More from Utah State University Extension

In northern Utah it is the most common borer in raspberries and blackberries, first documented there in the 1980s; larvae overwinter in the previous year's canes, and adults lay eggs in new first-year canes just as growth begins.[2]

Common questions

Why are the tips of my rose canes wilting in spring?
Raspberry horntail larvae tunneling inside the canes are a common cause.[1]
How far should I cut back an infested rose cane?
Prune down until the cut shows a healthy cross section.[1]

Sources

  1. University of California Statewide IPM Program, “Roses: Insects and Mites (Pest Notes).” ipm.ucanr.edu/home-and-landscape/roses-insects-and-mites/ (accessed 2026-10-06)
  2. Utah State University Extension, “Raspberry Horntail.” extension.usu.edu/planthealth/research/raspberry-horntail.php (accessed 2026-10-15)
  3. iNaturalist, “Phylloecus taxon page (order and family).” www.inaturalist.org/taxa/1050782 (accessed 2026-10-06)

Updated 2026-10-15. Built from sourced records. Spot an error? Tell us.