Pest profile

Strawberry Crown Moth

Synanthedon bibionipennis · Lepidoptera: Sesiidae[2]

The strawberry crown moth is a native clearwing moth whose larvae feed in strawberry crowns and roots; the adult strongly resembles a yellowjacket.[1]

Strawberry crown moth, a black and yellow clearwing moth that looks like a yellowjacket, on a flower
Strawberry crown moth, a black and yellow clearwing moth that looks like a yellowjacket, on a flower. (c) Hawk T., some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults are 12 to 15 mm long, black with yellow markings, and look like yellowjackets.[1]
  • Larvae are white with a brown head and 16 to 25 mm long when grown.[1]
  • Damaged plants pull away easily from their roots, which separates this damage from root weevil injury.[1]

Look-alikes

Look-alikeHow to tell them apart
YellowjacketsThe adult moth strongly resembles a yellowjacket, black with yellow markings.[1]
Root weevilsPlants hurt by crown moth larvae pull free from their roots easily; root weevil damage doesn't.[1]

Where it lives

Native to the Pacific Northwest, it has damaged strawberries in the northern Willamette Valley, most severely in Washington County, Oregon.[1]

US map: public records from 9 states since 1990 (GBIF).

Biology and life cycle

Larvae overwinter in the crown, become active in April and May, and pupate after a short feeding period.[1]

Adults emerge in late June and July and lay eggs on leaves near the base of plants; young larvae feed on the crown's outside, then bore in.[1]

There's one generation a year, and damage is sporadic.[1]

Damage and signs

  • Injured plants are stunted, may redden early and yield poorly; feeding wounds let root diseases in.[1]

Health risk

It feeds on plants; the PNW Insect Management Handbook mentions no risk to people.[1]

Control

Prevention

Don't put new plantings next to infested ones.[1]

Sanitation

Remove and destroy stunted, early-reddening infested plants, which tend to occur in clumps, and replant the gaps.[1]

Traps and physical control

In home gardens, cutting all the old leaves off June-bearers removes eggs and pushes fresh growth.[1]

Pesticides

Chemical control hasn't proven effective and isn't recommended.[1]

Common questions

Why do my strawberry plants come out of the ground so easily?
Strawberry crown moth larvae feed in the crown, so damaged tops separate easily from the roots.[1]
Is the yellowjacket-like insect on my strawberries a wasp?
It may be a strawberry crown moth, a moth that strongly resembles a yellowjacket.[1]

Sources

  1. Pacific Northwest Pest Management Handbooks (OSU, WSU, University of Idaho), “Strawberry: Strawberry crown moth (Insect Management Handbook).” pnwhandbooks.org/insect/small-fruit/strawberry/strawberry-strawberry-crown-moth (accessed 2026-10-06)
  2. iNaturalist, “Synanthedon bibionipennis taxon page (order and family).” www.inaturalist.org/taxa/319098 (accessed 2026-10-06)

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