You might have heard about dust mites that causes allergy in human beings. Certain type of mites' species damage plants also.
Mites are tiny organism that resembles spiders. These mites feed on the foliages of ornamental plants, vegetables, trees etc. Mites live in colonies, underside of new leaves and feed leaf tissue by piercing and sucking up the plant fluids. Feeding marks show up as light dots on the leaves afterwards leaves will show yellowing and curling (In chili downward curling of the leaves is caused by mites.). The plants show stunted growth as the new leaves are also infested by the mites and growth will cease. The development of flowers and fruit is affected.
Mites are common in hot, dry conditions. Mites develop fast during this condition, so if not noticed during the initial stage, will damage the crop. Severely infested leaves and branches need to be pruned and destroyed to avoid the spread of mites. Lady bird beetles are natural enemies of mites which feed on them.