Spider mites (Tetranychus spp; cotton red mite Oligonychus gossypii)
Spider mites feed on the lower surface of leaves. Adults are about 0.6 mm long. As a result the leaf surface appears tan or yellow and the upper surface has a speckle or mottled appearance. A close inspection of the lower leaf surface shows the mites as tiny moving greenish or reddish speckles. Heavily infested leaves turn yellow, curl up, dry and are shed. Mites produce a large amount of webbing. In heavy infestations a fine web may cover the leaves. Plants may die when infestation is severe, particularly in hot dry conditions.
- Provide good plant growing conditions, in particular enough water; water stressed plants are prone to mite damage.
- Avoid the use of broad-spectrum pesticides, which kill natural enemies and may result in mite outbreaks.
- Avoid planting next to infested fields.
- Sulphur preparations control mites. However, it should be noted that sulphur also kills predatory mites.