Dynamics of the ratio of phytophagans and changes in the taxonomic structure of entomoacarocomplex of apple agrocenoses of the Crimea

Abstract

The objective of the research is to study the species composition of the phytophagans’ complex of apple agrocenoses of the Crimea and to determine the factors that cause changes in the taxonomic structure. The research methods are common for entomology and plant protection techniques to identify and record the number of phytophagans in the fruit orchards: route examination, visual account under a binocular microscope, pheromone traps, hunting belts, shaking-off, mowing entomological nets. As a result of researches the relative instability of phytosanitary condition of apple orchards of the Crimea expressing in periodic outbreaks of mass reproduction of particular species occurring under the influence of biotic and abiotic factors is specified. Acari and Lepidoptera were determined as the most changeable orders. The composition of the dominant species within these orders changed almost completely from 1974 to 2018. The representatives of the orders Coleoptera and Homoptera have shown the greater stability. During the thirty-year period, the group of dominants included the same species. It has been found that the formation of the species composition of entomoacarocomplex of pests occurs under the influence of abiotic and anthropic factors. Biotic factors in industrial apple orchards do not have a significant impact on the number of phytophagans. Conclusion . It has been established that, as a whole, changes in weather conditions, range of pesticides used and growing technology led to a violation of the existing trophic links in the garden agrocenosis, caused qualitative and quantitative changes in the species composition of the entomoacarifauna and it is contributed to the formation of a certain group of dominants under the general depletion of species composition.