Spider mites

Definition

A large group of plant-feeding mites in the family Tetranychidae (subclass Acari), characterized by silk web-spinning behavior and piercing-sucking mouthparts used to extract contents from leaf cells. Most species are minute (0.4–0.8 mm), often brightly colored, and among the most economically significant agricultural pests due to rapid population growth and host-plant damage.

Etymology

Common name reflects the silk webbing spun on infested plants, analogous to spider silk; "mite" from Old English mīte, a small arachnid.

Example

The two-spotted spider mite (Tetranychus urticae) spins dense webbing on bean leaves and can complete a generation in five days at 30°C, making it a severe greenhouse pest.

Synonyms

• tetranychid mites

Related Terms

• Acari
• Tetranychidae
• gall mites
• phytophagous mites
• Integrated Pest Management
• web spinning
• stylet
• Parthenogenesis

Usage Notes

In agricultural contexts, "spider mite" is often used loosely for any visible web-spinning plant mite, though specialists reserve it for Tetranychidae. Distinguished from predatory mites (Phytoseiidae) and gall mites (Eriophyidae) by webbing habit and feeding damage pattern. Population outbreaks typically correlate with hot, dry conditions and pesticide-induced predator removal.