Bug FAQOystershell Scale
Lepidosaphes ulmi · Order: Hemiptera · Family: Diaspididae
Also called: Mediterranean fig scale, apple oystershell scale, fig oystershell scale, fig scale
Oystershell scale is an invasive scale insect that attacks trunks, branches, and leaves of trees and woody plants, and heavy infestations can kill branches or whole trees. Females lay about one hundred white eggs under their bodies before dying, and the tiny crawlers hatch in spring and settle permanently on thin bark.
Source: Wikipedia
How to recognize it
The upper side of the scale is a brown, waxy, banded covering, while the underside is cream coloured. The protective scale is formed from the larval skins and secretions after the crawler molts twice.
Source: Wikipedia
Size
Adult females can grow up to four millimetres long.
Source: Wikipedia
How to get rid of it
- Crawlers are vulnerable to several pesticides, but adult scales are protected by their waxy coating.
- In gardens, scrub trunks and branches, prune heavily infested wood, and remove it to reduce populations.
Source: Wikipedia
Where it lives
These insects attach themselves to bark and can be found on trunks, branches, and leaves of host plants.
Source: Wikipedia
Life cycle
After hatching, crawlers disperse on the host, locate thin bark, insert their stylet into vascular tissue, and remain there for life.
Source: Wikipedia
When you see it
Crawlers hatch in spring, roughly when the host plant’s buds are breaking.
Source: Wikipedia
Where it comes from
Lepidosaphes ulmi is a widely invasive scale insect found in many regions.
Source: Wikipedia
Where it is found in the US
Recorded in 22 of 51 states and DC. Most records: New York, Oregon, California, Arizona, Washington, Illinois, Minnesota, Utah.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: introduced in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
How can I get rid of oystershell scale?
Use pesticides that target crawlers and prune out heavily infested wood, removing it from the garden.
Source: Wikipedia
Same family (Diaspididae)
Elongate hemlock scaleFiorinia externaDamages trees, gardens or crops
Pine leaf scaleChionaspis pinifoliaeDamages trees, gardens or crops
False oleander scalePseudaulacaspis cockerelli
Oleander ScaleAspidiotus neriiDamages trees, gardens or crops
Pernicious ScaleDiaspidiotus perniciosusDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Lepidosaphes_ulmi
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-27 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-27.