Pest profile

Western Poplar Clearwing

Paranthrene robiniae · Lepidoptera: Sesiidae[2]

Western poplar clearwing larvae bore into birch, poplar and willow, especially stressed trees, in warm low-elevation areas of the West.[1]

Western poplar clearwing, a wasp-like moth with orange-brown forewings and a yellow and black banded abdomen
Western poplar clearwing, a wasp-like moth with orange-brown forewings and a yellow and black banded abdomen. (c) Daniel S., some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults have orange to brownish forewings, clear hind wings, a black thorax with a yellow border and a yellow abdomen with three black bands.[1]
  • The moth resembles a yellowjacket but has a thick waist and feathery antennae.[1]
  • Pale, dark-headed larvae have two hornlike spines on the back.[1]

Look-alikes

Look-alikeHow to tell them apart
YellowjacketsYellowjackets have a narrow waist and threadlike antennae; the moth has a thick waist and feathery antennae.[1]
Sycamore borerA related clearwing found mainly in sycamore.[1]

Where it lives

It's found throughout warm, low-elevation areas of the West, and is a pest in Southern California and the Central Valley.[1]

US map: public records from 11 states since 1990 (GBIF).

Biology and life cycle

Adults are active mainly May through July, and in Southern California also in November and February through May.[1]

Females lay eggs in bark cracks and wounds; larvae bore into bark, cambium or heartwood.[1]

Damage and signs

  • Poplar varieties vary widely in susceptibility, and willows tolerate infestation without apparent serious harm.[1]

Health risk

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

Control

Prevention

Check bark weekly for fresh pupal cases and use pheromone traps to time any action.[1]

Biological control

Commercial insect-killing nematodes injected into tunnels work against its larvae, and Apanteles wasps parasitize it.[1]

Pesticides

On high-value trees, bark sprays timed 10 to 14 days after first moth catch can reduce future infestations.[1]

Common questions

Is that a wasp or a moth on my poplar?
A thick waist and feathery antennae mean it's a clearwing moth, not a yellowjacket.[1]
Are willows hurt by western poplar clearwing?
UC IPM says willows tolerate infestation, apparently without serious harm.[1]

Sources

  1. University of California Statewide IPM Program, “Clearwing Moths (Pest Notes).” ipm.ucanr.edu/home-and-landscape/clearwing-moths/ (accessed 2026-10-06)
  2. iNaturalist, “Paranthrene robiniae taxon page (order and family).” www.inaturalist.org/taxa/354116 (accessed 2026-10-06)

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