Aonidiella aurantii

Definition

A species of armored scale insect (family Diaspididae, order Hemiptera) commonly known as the California red scale or red scale. Females secrete a circular, reddish-brown protective test (cover) and feed on the phloem of citrus and other woody plants, causing direct damage and transmitting plant pathogens. Native to South Asia, it is a major invasive pest of citrus orchards worldwide and a classic subject of biological control research.

Etymology

Latin aurantium (orange), referring to its primary host and the color of its protective covering.

Example

Aonidiella aurantii infestations on grapefruit trees are monitored by counting the number of live females per fruit to determine if pesticide or parasitoid wasp (Aphytis melinus) release thresholds have been exceeded.

Synonyms

• California red scale
• red scale

Related Terms

• Diaspididae
• armored scale
• test
• Aphytis
• Integrated Pest Management
• phloem feeder
• Maskell 1879

Usage Notes

The spelling Aonidiella auranti (single 'i') is a common error; the valid name established by Maskell in 1879 is Aonidiella aurantii. The species is frequently confused with the yellow scale (Aonidiella citrina), which has a paler, more flexible test and prefers lemon over orange. In biological control literature, 'red scale' without qualification usually refers to this species.