Pest profile

Dogwood Borer

Synanthedon scitula · Lepidoptera: Sesiidae[3]

Dogwood borer caterpillars enter at bark wounds, so preventing mower and trimmer injury is the key defense.[1]

Dogwood borer, a wasp-like clearwing moth with a bluish-black body and yellow bands, on a pale surface
Dogwood borer, a wasp-like clearwing moth with a bluish-black body and yellow bands, on a pale surface. (c) Louis Imbeau, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults are wasp-like clearwing moths about 1/2 inch long, bluish-black with yellow bands on the second and fourth abdominal segments.[1]
  • Larvae are cream-colored with reddish-brown heads.[1]
  • Signs include swollen, knotty bark, sloughing bark, sawdust-like frass and leaves reddening early.[1]

Look-alikes

Look-alikeHow to tell them apart
Ash/lilac borerAnother clearwing moth borer, in ash and lilac.[2]

Where it lives

It attacks many ornamental, fruit and nut trees and has caused growing problems in northeastern apple orchards since the 1980s.[1]

US map: public records from 36 states since 1990 (GBIF).

Biology and life cycle

Adults emerge in spring and lay eggs singly on bark, preferring injured areas and apple burr knots.[1]

Eggs hatch in eight to nine days; larvae take about a year through seven instars and overwinter under bark.[1]

Damage and signs

  • Larvae bore into the cambium, making infested areas swollen, knotty or gall-like.[1]

Health risk

It feeds in trees; UF/IFAS mentions no risk to people.[1]

Control

Prevention

Avoid physical injury, especially from lawn mowers; brace new trees and remove dead or cankered branches.[1]

Vinyl tree wraps on young dogwoods have increased infestations in some cases.[1]

When to call a professional

For insecticide options, contact your local Extension office.[1]

Common questions

Why is the base of my dogwood swollen with sawdust?
Dogwood borer larvae tunneling at wounds cause swollen bark and frass.[1]
How do I prevent it?
Keep mowers and trimmers away from the trunk.[1]

Sources

  1. University of Florida IFAS Extension (Featured Creatures), “Dogwood Borer, Synanthedon scitula (EENY-374).” edis.ifas.ufl.edu/publication/IN671 (accessed 2026-10-06)
  2. University of California Statewide IPM Program, “Pest Notes: Clearwing Moths (Publication 7477).” ipm.ucanr.edu/PMG/PESTNOTES/pn7477.html (accessed 2026-10-06)
  3. iNaturalist, “Synanthedon scitula taxon page (order and family).” www.inaturalist.org/taxa/232126 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.