Spider mites have needle-like sucking mouthparts. They feed by penetrating the plant tissue with their mouthparts. Large populations may cover entire plants with webbing. These webs are also used to move themselves. Because spider mites are so small they can move through ventilators.
Each female two-spotted spider mite lays 10-20 eggs per day, 80-120 altogether during its life cycle of up to 4 weeks. These are mostly attached to the silk webbing. The six-legged larvae hatch after 3-15 days. Newly hatched larvae are almost colourless and have bright red eyes. They moult three times within 4-5 days, towards protonymph, then deutonymph and at last adult. Both adults and nymphs have 8 legs.
The first visible symptoms are small yellowish or whitish specks, mainly around the midrib and larger veins. If these spots grow bigger and merge, the empty cells give some areas of the leaf a whitish or silverytransparent appearance.
To minimize the risk and rapid spread of spider mite infestations, try to keep the temperature lower (<25 °C) and the humidity higher (>60 %), since this will slow the rate of reproduction. However, higher humidity is needed for the predators of spider mite. Keep your growing areas clean, remove leaf litter. Adequate irrigation is important, because water-stressed plants are more likely to be damaged.
When you see spider mites (recognizable by silk webs on top of the leaves), remove the affected leaves. Flush the plant thoroughly with a mixture of alcohol and soap. Repeat this treatment several times a week.
You can also use natural enemies: predatory mites, ladybirds, predatory bugs and lacewings.