Purple scale

Pronunciation
/PUR-puhl SKAYL/
Category
Taxonomy
Singular
purple scale
Plural
purple scales

Definition

A for Lepidosaphes beckii (: ), a diaspidid insect and economically important pest of citrus and related Rutaceae. The female secretes a distinctive elongated, comma-shaped or mussel-like test (covering) that appears purple-brown to dark gray, under which she feeds on phloem sap, causing leaf yellowing, fruit blemishing, twig dieback, and reduced tree vigor. Heavy can lead to defoliation and secondary . The is parthenogenetic in many and has a distribution in tropical and subtropical citrus-growing regions.

Etymology

From the purple-brown coloration of the female's protective test; also called mussel for its resemblance to a small bivalve shell.

Example

Purple on grapefruit are often concentrated on the fruit surface and upper leaf surfaces, where the dark comma-shaped tests are visible to the naked and can downgrade fruit for fresh market.

Synonyms

  • mussel scale
  • citrus mussel scale
  • orange scale
  • comma scale
  • mussel purple scale
  • Lepidosaphes beckii

Related Terms

Usage Notes

The 'purple ' is applied specifically to Lepidosaphes beckii and should not be confused with other pigmented scale insects such as the red scale (). In field diagnostics, the comma-shaped test distinguishes purple scale from the circular tests of most other diaspidids. The name 'mussel scale' is preferred in some regions and agricultural extension literature. When used as a mass noun ('purple scale damage'), the term refers to the pest condition rather than individual insects.