EN
Since the eighties a distinct decrease in outlays for, and a number of specialists in taxonomy in the world, including the USA and Great Britain, were observed. During last decade, however, this had a serious bearing in modern plant protection. If effective, all the methods of plant protection but particularly quarantine, plant resistance and biological methods have to be initiated on proper species determination of arthropods. Besides morphological, several new methods are now in use in the taxonomy, particularly the molecular taxonomy. Erroneous identifications are often very expensive. This review refers to own and other authors, experiences.