Climate change has a significant impact on the bioecology of the flower beetle weevil Anthonomus pomorum (Linnaeus, 1758) (Coleoptera: Curculionidae), one of the main pests of pome fruit crops - apple and pear. Survival and the degree of harmfulness of it is closely related to the specific phase of development of the host plant. A. pomorum lays eggs only in tight buds that have not yet opened. Therefore, the phenological synchronization of the development of the plant and the flower weevil is of decisive importance for the pest, which strongly depends on weather conditions, to a greater extent on air temperature. Different crops, their varieties, as well as phytophages react differently to changing weather conditions. This makes it difficult to accurately signal the release of the weevil from winter dormancy and the time of mass settlement of plantations. The sum of effective temperatures (SET) above 0˚С used for this purpose in the mild climatic conditions of Western Europe, calculated from January 1 or February, does not justify itself in the more continental conditions of the Non-Chernozem zone of Russia, it has a large fluctuation amplitude. For the specified zone, the calculation of the SET from March 1 is suitable. More accurate signaling can only be achieved by combining different methods – SET for a landmark, visual observation, the use of traps, shaking plants. Placing on the same area varieties of different flowering periods, as well as apple and pear trees, increases the reproductive potential and the degree of harmfulness of A. pomorum. Damage to apple trees in some years can reach an average of 72.5%, pears – 9.8%.