Mealybugs

Definition

Soft-bodied, unarmored scale insects in the family Pseudococcidae (order Hemiptera), characterized by a white, powdery or filamentous waxy secretion that covers the body. They feed by piercing plant tissues and sucking phloem sap, excreting honeydew that supports sooty mold growth and attracts tending ants. Many species are economically significant pests of greenhouse crops, ornamentals, and subtropical agriculture; some transmit plant viruses.

Etymology

From the meal-like, powdery wax coating that gives these insects a flour-dusted appearance.

Example

The citrus mealybug (Planococcus citri) is a major pest of greenhouse poinsettias and can vector the Grapevine leafroll-associated virus; ant-tended mealybug colonies on coffee plants often require targeted ant management for effective biological control.

Synonyms

• pseudococcids

Related Terms

• scale insects
• honeydew
• Coccoidea
• Soft scales
• ant-plant mutualism
• phloem feeders
• Sooty mold

Usage Notes

Technically refers to members of family Pseudococcidae, not all waxy scale insects; contrast with armored scales (Diaspididae) which have a hard, separable test. The common name is sometimes applied loosely to other waxy Sternorrhyncha, but specialists reserve it for Pseudococcidae. Sexual dimorphism is extreme: females are sessile, oval, and wingless; males are tiny, winged, and non-feeding.