San Jose Scale
Comstockaspis perniciosa
Basic Details
Description
Taxonomy
Features
Translations
Basic Details
NameSan Jose Scale
DescriptionSan Jose scale appears as tiny grey bumps that create distinct red halos on fruit and bark. Identify these 'bullseye' marks to prevent branch dieback and tree death.
TypeInsect
FamilyDiaspididae
GenusComstockaspis
TribeAspidiotini
Taxonomy & Features
PhylumArthropoda
SubphylumHexapoda
ClassInsecta
OrderHemiptera
SubfamilyAspidiotinae
Features
- One of the most destructive scale insects globally. Attacks over 700 species of trees and shrubs, particularly apples, pears, peaches, and plums
- Adults are tiny (2 mm), circular, greyish-white 'armored' insects that look like a miniature volcano with a central yellow or grey nipple
- They suck sap from the bark, leaves, and fruit. A characteristic symptom is a bright red-to-purple 'halo' or bullseye appearing around each scale on green fruit
- Heavy infestations can completely encrust branches, giving them a grey, scurfy, or ash-like appearance. Underlying sapwood may show red staining
- Infestation leads to reduced tree vigor, leaf yellowing, and significant branch dieback. Left untreated, it can kill mature trees within 2-3 years
- The 'crawlers' (the only mobile stage) are bright yellow, microscopic, and active in late spring. They move to new parts of the tree or are carried by wind/birds
- Overwinters as immature 'black cap' scales on the bark of twigs and branches. They resume feeding in spring as sap flow begins
- Different from 'soft' scales because they do not produce honeydew or attract sooty mold. They remain permanently attached once they begin feeding
- Control by applying 2% horticultural oil or lime-sulfur during the dormant season to suffocate the overwintering scales
- Monitor for yellow crawlers using double-sided sticky tape on branches in late spring. Treat with insecticidal soap or neem oil during the crawler phase
Names in Different Languages
Latin / ScientificComstockaspis perniciosa
English (Alternate)Armored scale
Hindiसैन जोस स्केल (San jose scale)
Tamilசான் ஜோஸ் செதில் பூச்சி (San jose sethil puchi)
Teluguసాన్ జోస్ స్కేల్ (San jose scale)
Malayalamസാൻ ജോസ് സ്കെയിൽ (Sān jōs skeyil)
Kannadaಸ್ಯಾನ್ ಜೋಸ್ ಸ್ಕೇಲ್ (Syān jōs skēl)
Sanskritशकल-कीट (Śakala-kīṭa)
Bengaliসান হোসে স্কেল (San jose scale)
Frenchpou de San José
Russianкалифорнийская щитовка (kaliforniyskaya shchitovka)
Spanishpiojo de San José
GermanSan-José-Schildlaus
