LONGTERM FORECAST OF BIOLOGICAL DEVELOPMENT OF PHYTOPHAGES ON BLACK CURRANT

Abstract

The article presents the results of scientific research on the  biological  development of  the  large currant aphid, the red currant head aphid and the  gooseberry  shoot  aphid  in  the  currant agrocenosis. Based on  the  analysis  of  the  multi-year  dynamics  of  the  development of  phytophages, a phenological calendar was built, which clearly shows the period of manifestation of the greatest harmfulness of these pests, which is indicated in the third decade of April, while according to the phenological phase of development, this is the VI stage of the biological development of currants. Aphids overwinter in the egg stage at the base of the currant bud. The embryonic development of the egg ends at the beginning of the plant's sap flow. The metamorphosis of this species refers to an incomplete transformation, and therefore parthenogenesis was observed during the experiment. At the 4th stage of organogenesis, we observed the emergence of larvae of the founders, light green in color and spiky sucking mouthparts, which after 2-3 days begin active feeding, which was evidenced by damaged leaves that changed their color over time. The color of leaves damaged by redcurrant aphid has a clear transition from light yellow to red with a halo-shaped bulge. In this species, the salivary enzyme enhances the growth and development of cells, while in the gooseberry shoot aphid, on the contrary, cells die and at the same time cause cell death. According to our observations, it has been proven that the development of these phytophages falls on the stage of organogenesis of currant blossoms, and it is strictly forbidden to carry out any plant protection measures during this period. And therefore, we conducted a long-term study of both black currant and sucking phytophages. Such a significant plant-phytophagous combination makes it possible to carry out preventive actions early in the spring on the biological development of sucking phytophages, where in recent years their harmfulness occupies one of the main places, while parthenogenetic females cause significant damage, reducing the yield and quality of berries due to disruption of the normal flow physiological processes of photosynthesis. As a result of nutrition of a parthenogenetic individual, the shoots lag behind in growth, have clearly expressed curvatures of various shapes. It is possible to reduce the colonization of black currant by sucking phytophages by implementing phenological forecasting.