Red spider mite

What you see

Almost invisible at 0.5 mm - use a hand lens or tap a leaf over white paper and watch for moving dots. Straw-coloured to red with two dark spots. Fine silk webbing between leaf and stem in bad cases.

Damage

Fine pale stippling all over the leaf surface, giving a dusty bronzed look. Leaves turn grey-bronze and drop. Webbing on shoot tips when severe.

Lifecycle on this coast

Egg to adult in under a week at 30 C - explosive in hot dry weather. Overwinters as orange females in bark crevices and greenhouse frames.

When to act

Act at first stippling; by the time you see webbing, the population is enormous and the leaf damage is permanent.

Months: May, June, July, August, September

Plants it bothers

Tomato, Cucumber, Aubergine, Citrus, Strawberry, Grape, Rose, Bay laurel

Natural enemies

Predatory mite (Phytoseiulus), Lacewing, Minute pirate bug, Ladybird

Remedies

Insecticidal soap spray, Horticultural oil (white oil), Wettable sulphur, Water jet and finger squash

The thing people get wrong

Spider mite is a symptom of hot, dry, dusty air as much as an infestation. It explodes on plants against a sun-baked wall and on anything under drought stress. Raising humidity - a daily misting of the undersides, mulch, a plant moved out of reflected heat - does more than most sprays, and dry dusty leaves are practically an invitation.