Two-Spotted Spider Mite
Scientific group or name: Tetranychus urticae
Overview
Two-spotted spider mite is a major warm-weather pest that feeds on the undersides of leaves. It can reproduce rapidly under hot, dry conditions.
Host plants
A very wide range of vegetables, soft fruit, ornamentals and protected crops.
Identification
Adults are tiny, usually pale green to yellowish, with two darker patches visible through the body. Overwintering females can be orange-red. Fine webbing appears as populations increase.
Damage and symptoms
Feeding causes pale stippling, bronzing, reduced photosynthesis, leaf drying and premature leaf loss. Severe colonies cover foliage with webbing.
Lifecycle and favourable conditions
Hot, dry, sheltered conditions strongly favour population growth. Water-stressed plants are particularly vulnerable.
Monitoring
Inspect lower leaves with a hand lens, focusing on warm edges, dry areas and previously affected plants. Record both mites and eggs.
Management
Remove heavily infested leaves where safe, reduce dust and plant stress, avoid unnecessary broad-spectrum pesticides and prevent movement on clothing and tools.
Biological control and natural enemies
Phytoseiulus persimilis is widely used against active colonies. Neoseiulus californicus and other predatory mites may provide greater persistence where conditions or prey levels fluctuate.
Biological control should be selected only after the pest has been identified and the crop, temperature, growing environment and pest pressure have been considered.
Related BioWiki pages
Spider Mites · Phytoseiulus persimilis
This page provides general integrated pest-management information. Identification and control decisions should be confirmed for the crop and local situation.