Pest profile

Oak Skeletonizer

Bucculatrix albertiella · Lepidoptera: Bucculatricidae[2]

The oak skeletonizer, also called the oak ribbed casemaker, is a tiny moth whose larvae mine and skeletonize oak leaves until they're nearly transparent.[1]

Ribbed white cocoon of the oak skeletonizer on a damaged oak leaf
Ribbed white cocoon of the oak skeletonizer on a damaged oak leaf. (c) Henrik Kibak, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults are mottled white, brown and black moths with a wingspread of about 1/3 inch.[1]
  • Mature larvae are pale yellow to green and about 1/4 inch long.[1]
  • Mature larvae spin oblong white cocoons with distinct lengthwise ribs on leaves, twigs and objects below.[1]

Where it lives

It's reported on California valley oak and coast live oak, and the PNW Insect Management Handbook covers it as an oak pest.[1]

US map: public records from 2 states since 1990 (GBIF).

Biology and life cycle

Young larvae mine inside leaves; older larvae feed on the undersides, leaving only the upper surface and veins.[1]

It appears to overwinter inside its cocoon; young larvae make flat, white, round cocoons to hibernate.[1]

Moths appear in spring and lay eggs under leaves, and there are two generations a year.[1]

Damage and signs

  • Skeletonized leaves turn brown, and badly damaged ones can be almost transparent.[1]

Health risk

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

Control

Prevention

Cocoons are easily carried from place to place on infested plant material.[1]

Sanitation

Rake up fallen leaves to remove cocoons, and destroy them by deep composting.[1]

Biological control

Natural enemies probably help keep it in check; avoid broad-spectrum insecticides that kill them.[1]

Common questions

What are the tiny ribbed white cocoons on my oak leaves?
Likely oak skeletonizer (oak ribbed casemaker) cocoons, which are oblong and white with lengthwise ribs.[1]
Why are my oak leaves turning see-through?
Older oak skeletonizer larvae eat the leaf undersides, leaving only the upper surface and veins.[1]

Sources

  1. Pacific Northwest Pest Management Handbooks (OSU, WSU, University of Idaho), “Oak (Quercus): Oak skeletonizer (Insect Management Handbook).” pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/oak-quercus-oak-skeletonizer (accessed 2026-10-06)
  2. iNaturalist, “Bucculatrix albertiella taxon page (order and family).” www.inaturalist.org/taxa/469759 (accessed 2026-10-06)

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