What are the main causes of pests and diseases?

Diseases and pests: Diseases and pests are also called. Diseases refer to abnormal pathological phenomena in the external form, such as withering, rot, spots, mildew powder, flowers and leaves, etc., in which plants are infected by harmful organisms or affected by adverse environmental conditions and their normal metabolism is disturbed. There are many kinds of animals that harm medicinal plants, among which insects are the main ones, as well as mites, snails and rats. Although many insects belong to pests, there are also beneficial insects, which should be protected, propagated and utilized. Pest control methods include agricultural control, biological control, physical control, mechanical control and chemical control.