Pests of energy willow and practices to control their number

Abstract

Purpose. To determine the pest species composition in bioenergy willow plantations and develop practices to control their number.Methods. Field, accounting, statistical and analytical.Results. The main pests species composition of bioenergy willow plantation in different zones have been determined, namely in the zone of sufficient moisture at the Uladivka-Liulyntsi Research Breeding Station (ULRBS), in the zone of insufficient moisture at Veselyi Podil Research Breeding Station (VPRBS) and in the zone of unstable moisture at the Bila Tserkva Research Breeding Station (BTsRBS). Of the soil pests, the most harmful for sugar beet species were found May bug, June bug and marble bug, the number of which in different areas ranged from 0.1 to 0.4 (VPRBS) to 2.0 to 4.0 (ULRBS) per 1 m2. In addition to these harmful species, there were larvae of grasshoppers and Tenebrionidae, the number of which was 0.9 to 4.0 per 1 m2, as well as larvae of cereal chafer and caterpillars of winter owl moth. The density of the soil pests population somewhat exceeded the economic thresholds of harmfulness, which should be taken into account when establishing willow plantations and during the growing season. With regard to terrestrial species, the most dangerous for willow is brown willow beetle, willow aphid and apple black miner, the number of which was also not the same everywhere. Thus, the highest population density of the brown willow beetle (beetle/10 plants) was recorded in BTsRBS (3.0 to 36.0), in ULRBS (0.5 to 3.0) and VPRBS (0.2 to 3.6). The willow aphid was found in all zones at the settlement score of 1.0 to 1.5, while apple black miner was recorded only in spring in ULRBS and BTsRBS at the settlement score of 1.0. The control of the number of phytophages in willow plantation was carried out with the aid of insecticides through pre-planting soaking cuttings and spraying planted cuttings. Soaking of cuttings in solutions of systemic action insecticides contributes to a 12.9 ̶ 22.9% increase in the plant survival compared to soaking them in water. The use of insecticides for spraying cuttings during vegetation season provides a high efficiency (76.7–100.0%) of pest control.Conclusions. Energy willow is damaged by a number of soil and terrestrial pests, namely larvae of May bug, grasshopper, Tenebrionidas, cereal chafer, Carabidae (soil pests), and brown willow beetle, willow aphid and apple bark miner (terrestrial pests). The control of the number of these phytophages is carried out mainly with the aid of insecticides through pre-planting soaking cuttings or spraying planted cuttings.