Pest profile

Euonymus Scale

Unaspis euonymi · Hemiptera: Diaspididae[2]

Euonymus scale is a key pest of euonymus, pachysandra and bittersweet; vine-type euonymus are extremely susceptible.[1]

Euonymus leaf with many narrow white male euonymus scales and a few brown females
Euonymus leaf with many narrow white male euonymus scales and a few brown females. (c) Jon Mortin, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Male covers are white, narrow and waxy, about 0.8 mm long; females are grayish-brown, flat and pear-shaped, about 2 mm.[1]
  • Crawlers are tiny and yellowish-orange.[1]
  • Feeding causes yellowish stippling or spotting on leaves.[1]

Look-alikes

Look-alikeHow to tell them apart
Other scale insectsEuonymus scale is an armored scale native to Japan and China, now established in the U.S. and Canada.[1]

Where it lives

Native to Japan and China, it's established in the United States and Canada.[1]

US map: public records from 24 states since 1990 (GBIF).

Biology and life cycle

Fertilized females overwinter and lay eggs under their covers in late April and May; eggs hatch over two to three weeks.[1]

Development takes four to six weeks, and a second generation of crawlers appears from late July through August.[1]

Damage and signs

  • Heavy infestations on twigs or leaves can defoliate plants, kill twigs or kill the whole plant.[1]

Health risk

It feeds on plants only; Penn State mentions no risk to people.[1]

Control

Traps and physical control

Prune and destroy heavily infested branches.[1]

Biological control

The lady beetle Chilocorus kuwanae was introduced in the eastern U.S. to help control it.[1]

Pesticides

Treat first-generation crawlers in late May through June and second-generation crawlers in late July through August, following the label.[1]

Common questions

What are the white specks covering my euonymus?
Probably the white male covers of euonymus scale.[1]
When should I spray?
When crawlers are active: late May through June, and again late July through August.[1]

Sources

  1. Penn State Extension, “Euonymus Scale.” extension.psu.edu/euonymus-scale (accessed 2026-10-06)
  2. iNaturalist, “Unaspis euonymi taxon page (order and family).” www.inaturalist.org/taxa/512010 (accessed 2026-10-06)

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