Pests discouraging farming
Abundancy of farm pests
Among vertebrate animals, many crop pests are mammals, especially in the order of rodents, and birds. Among invertebrates, certain species of gastropods and a large number of roundworms from the class of nematodes harm crops. The most varied and numerous species of crop pests are arthropods-insects, arachnids (mites), and some species of millipedes and crustaceans (wood lice). Diseases vary from viral, bacterial, and nutritional to fungal, environmental and non-specific.
The FAO has estimated that annual worldwide losses done by plant pests and diseases amount to approximately 20-25% of the potential worldwide yield of food crops.