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How to identify it
- The female's cover is circular, about 0.06 inch (1.5 mm) across, and light gray with a brown peak slightly off center.[1][3]
- Under the cover, UC IPM describes the female's body as reddish purple; the Diaspididae of the World account says living females are light pink to orange-yellow and turn dark red-brown with age.[1][3]
- Male covers are elongate, white or light gray, with a yellow cast skin at one end.[3]
- The scales sit directly on twigs, branches and trunks, under moss and lichens. UC IPM says they cannot survive without this shelter.[1][3]
- Telling it apart from other armored scales with certainty requires examining slide-mounted adult females under a microscope.[3]
Where it lives
Probably native to Europe, it has spread widely and occurs in California. It is not established in the United Kingdom and has not been recorded from Australia or the Pacific islands.[3][1]
Biology and life cycle
It has been recorded on plants in eight families, especially the rose family. It prefers walnut, stone fruit and pome fruit trees and is common on Heteromeles in California.[3]
Other hosts include horse chestnut, barberry, dogwood, hawthorn, quince, honeylocust, apple, medlar, olive, photinia, Prunus, pear and Ribes.[3]
It spends the winter mostly as mature, fertilized females. In California and Central Europe it has one generation per year.[1][3]
Crawlers often settle near the parent females, so scale covers can pile up in several layers. Females in the former USSR laid 20 to 90 eggs each.[3]
Damage and signs
- It does not feed on fruit. It feeds directly on the wood, which lowers tree vigor and reduces fruit size.[1]
- Plant tissue stops growing where the scales feed, so twigs and branches become pitted and deformed and break easily. Heavy infestations distort and kill branches, especially on pear and plum.[3]
- In California it is not particularly injurious except on walnut trees with heavy lichen growth, where large populations weaken the trees and reduce nut size and yield.[3]
- Apple trees can tolerate fairly high populations without apparent damage.[2]
Health risk
The sources describe it only as a pest of trees; none mentions any risk to people or pets.[1][3]
Control
Prevention
Look closely at twigs for circular whitish to gray scale covers with a yellow or brown center, especially where bark is covered with moss and lichens.[3][1]
Sanitation
Where limbs are heavily covered with moss and lichens, remove the moss and lichen so the scale loses its shelter.[1]
Biological control
No efficient parasitoids of this scale are known, although Aphytis and Encarsia wasps and Chilocorus lady beetles have been recorded attacking it in Europe.[3]
Pesticides
Dormant sprays applied for other scales generally keep Italian pear scale under control. On mossy, lichen-covered limbs, UC IPM suggests adding Bordeaux mixture to the dormant spray; Bordeaux mixtures are acceptable for organic growers if all ingredients are certified.[1]
Common questions
- Why do I find this scale under lichens on my pear tree?
- Italian pear scale lives under moss and lichens on the wood, and UC IPM says it cannot survive without that shelter.[1]
- Does Italian pear scale damage the fruit?
- It does not feed on fruit, but feeding on the wood can weaken the tree and reduce fruit size.[1]
- Do I need a special spray for it?
- Usually not. Dormant sprays applied for other scales generally keep it under control unless limbs are heavily covered with moss and lichens.[1][2]
Sources
- University of California Statewide IPM Program, “Italian Pear Scale, UC IPM Pest Management Guidelines: Pear.” ipm.ucanr.edu/agriculture/pear/italian-pear-scale/ (accessed 2026-11-09)
- University of California Statewide IPM Program, “Italian Pear Scale, UC IPM Pest Management Guidelines: Apple.” ipm.ucanr.edu/agriculture/apple/italian-pear-scale (accessed 2026-11-09)
- Diaspididae of the World (Naturalis Biodiversity Center, Linnaeus NG), “Epidiaspis leperii, Diaspididae of the World 2.0 (species account).” diaspididae.linnaeus.naturalis.nl/linnaeus_ng/app/views/species/taxon.php?id=113075 (accessed 2026-11-09)
- iNaturalist, “Epidiaspis leperii taxon page (order and family).” www.inaturalist.org/taxa/917300 (accessed 2026-11-09)