Pest profile

Maskell Scale

Lepidosaphes pallida (NC State lists it as L. maskelli) · Hemiptera: Diaspididae[3]

Maskell scale is a tiny brown armored scale shaped like an oyster shell that settles on the needles of junipers, Japanese cedar (Cryptomeria) and other conifers and can cause browning and twig dieback.[1][2]

Single Maskell scale, a tiny brown oystershell-shaped armored scale, on a conifer needle
Single Maskell scale, a tiny brown oystershell-shaped armored scale, on a conifer needle. (c) Angus Campbell, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Female armor is brown, up to 1/16 inch long and oystershell-shaped; male armor is smaller and slender.[1][2]
  • Young scales' armor is pale brown and almost translucent; crawlers are flat and yellow.[1]
  • In established populations many scales are dead, because the armor stays on the plant long after the insect dies.[1]

Where it lives

UMass reports it in New Jersey, New York, Delaware, Pennsylvania and at least seven more states, and probably more widely; NC State covers it in North Carolina.[1][2]

Biology and life cycle

Eggs laid under the female's armor hatch in one to three weeks, and crawlers settle on needles and build pale armor.[1]

About two months later, females begin laying eggs for a new generation.[1]

Winged males find females to mate and soon die; they lack mouthparts.[1]

Damage and signs

  • Junipers are the most frequently reported hosts; it also attacks arborvitae, Chamaecyparis, Cryptomeria, cypress, deodar cedar, umbrella pine, yew and others, more than 21 plant genera in all.[1][2]
  • On Cryptomeria it can cause browning and twig dieback, and it can become a serious pest of junipers.[1][2]

Health risk

None to people or pets.[1][2]

Control

Prevention

Scout in early spring for crawler activity.[1]

Biological control

Tiny parasitic wasps often heavily parasitize it, though populations occasionally escape them.[1]

Pesticides

Treat infested plants with horticultural oil, at the maximum label rate in cold weather and the growing-season rate in summer.[1]

Common questions

What are the tiny brown specks on my juniper needles?
Possibly Maskell scale, a 1/16-inch oystershell-shaped armored scale.[1][2]
Are the scales alive?
Not necessarily; armor stays on the plant long after the scale dies, so check for live insects before treating.[1]
How do I treat Maskell scale?
Horticultural oil at the label's dormant rate in cold weather or growing-season rate in summer.[1]

Sources

  1. NC State Extension, “Maskell Scale (PDIC Factsheet).” content.ces.ncsu.edu/maskell-scale (accessed 2026-10-15)
  2. UMass Extension Landscape, Nursery and Urban Forestry Program (Landscape Insect & Mite Guide), “Lepidosaphes pallida (Maskell Scale).” www.umass.edu/agriculture-food-environment/landscape/publications-resources/insect-mite-guide/lepidosaphes-pallida (accessed 2026-10-15)
  3. iNaturalist, “Lepidosaphes pallida taxon page (order and family).” www.inaturalist.org/taxa/391463 (accessed 2026-10-06)

Updated 2026-10-15. Built from sourced records. Spot an error? Tell us.