Spider Mite

Two-spotted spider mite is not an insect but a mite, related to spiders and ticks. Adults are barely visible to the naked eye, around 0.5mm long, oval-shaped, and pale yellow-green to greenish with two darker patches on either side of the body (hence the name). In cooler months some mites turn orange-red. Eggs are tiny, round and translucent to straw-coloured, laid on the underside of leaves. Nymphs look like smaller, paler versions of the adults and pass through several moults before maturing. All life stages are usually found clustered on the undersides of leaves, often along the midrib and veins, where fine silk webbing may be spun over heavily infested foliage.

This pest attacks an enormous range of plants across Australian gardens, including vegetables, ornamentals, fruit trees, berries and indoor plants. It is one of the most common mite pests in home gardens nationwide.

Populations build fastest during hot, dry conditions, typically from late spring through summer and into early autumn. Life cycles can be completed in as little as a week when it's warm, so numbers can explode quickly once established. Dusty, drought-stressed plants are particularly prone to outbreaks, and mites often move in from weeds or nearby plants before spreading through a garden bed or greenhouse.

Management relies on regular monitoring, especially in warm weather, since early detection makes control much easier. Keeping plants well watered and reducing dust and drought stress helps limit outbreaks. Encouraging predatory mites and other beneficial insects, removing badly affected leaves, and avoiding broad-spectrum sprays that kill natural predators are all useful non-chemical strategies. Isolating new or affected plants can help stop mites spreading to unaffected areas.