Biological features and phenology of the odd bark beetle development (Xyleborus dispar F.) on the territory of Transcarpathia

Abstract

On the basis of literature analysis and primary research biological features of such pest as an odd bark beetle Xyleborus dispar F are described and the phenology of its development is established. This polyphag is known to harm both forest plantations and fruit cultures. The main species damaged by bark beetles include both coniferous and deciduous and fruit trees (apple, pear, plum, bird cherry, rowan). Significant damage is caused by apple orchards of intensive type which due to planting density and softness of wood are vulnerable to damage by phytophagous. The main difficulty in the fight against bark beetle is associated with a hidden way of life and the passage of almost all stages of development inside the tree. One of the main signs of bark beetle development in Transcarpathia is early flight. Already in early April, there are signs of penetration of bark into the tree - the appearance of smut on the bark and wood chips in the trunk strip. Another danger is the high level of fertility of bark beetles, which threatens the rapid spread of the adult pest, which in turn leads to significant economic losses for intensive orchards and causes irreparable damage to apple orchards. Since the odd-numbered western bark beetle is a relatively new pest for apple orchards in Transcarpathia, the preparation and calculation of the appearance and passage of the main phases of development is a thorough step in the fight against this polyphagous. Intensive apple orchards which are particularly vulnerable to phytophagous damage due to planting density and soft wood significantly suffer from the pest. Based on a three-year monitoring process a phenogram of bark beetle development in the lowland part of Transcarpathia was developed, and the approximate values of effective temperatures required for the passage through different phases of the pest were calculated. It was established that during the growing season in the study area the odd western bark beetle develops in one generation. However, the summer generation of adults which develop in trunks of apple trees emerges in mid-July and repopulates new trees for final wintering. This creates an additional need for measures to protect apple trees from pests. The results of the research allow gardeners to adjust the integrated system of orchard protection, as well as to include additional pest detection measures in the program of effective apple growing.