ABSTRACT
In a specific transfer, throughout the life cycle, insects "cultivate" microscopic pathogens on the vegetable substrate that serves as their nutrient source. Therefore, insect phytophages are potential vectors in transfer of disease agents. The vectors of diseases are fungi, virus, bacteria, and mycoplasma. When comparing the frequencies and spreading of different diseases, fungal diseases are most common and diverse: 80% of all plant diseases fall into this category. The bacterial diseases transmitted by insects are also numerous. One can identify the special group of bacterioses that are propagated most exclusively by insects. Mycoplasma diseases were first diagnosed in 1967 by Japanese virologists. More than 300 diseases, formerly considered to be viral infections, are known to be phytoplasma diseases. The most dangerous phytoplasma disease of the trees in North America is the elm phloem necrosis. Yet another example of phytoplasma disease is the ash yellows.
