Phytophagous energy plantings of willow

Abstract

Purpose. Investigation of the species composition and the number of plant feeders in energy willow plantations.
 Method. Field, accounting, statistical, analytical.
 Results. Today, growing plants for the production of biofuels is a promising source of energy that have a high potential for energy recovery. Biomass of energy crops such as willow is a renewable energy source with zero balance of carbon dioxide and methane. Fast-growing trees such as willow are perennials that are able to produce biomass over a long period. However, like any plant, willow is a host tree for many living organisms, including insects. According to the results of our observations and records, among the latter, this crop is damaged by both soil and land plant feeders. Of the soil pests, the most dangerous for willow are the larvae of several species of May beetles, which feed on the roots causing significant inhibition of growth and development of plants or even their death. The number of these insects per square meter in different zones ranges from 0.6–0.8 to 1.6–1.9. In the focuses, the population density of the larvae per square meter reaches 8.8. In addition to beetle larvae, the root system of willow is damaged by the larvae of click beetles, Elatericlae, Blaps and Anisoplia austriaca larvae. The number of these larvae per square meter ranges between 0.8 and 2.3 and between 0.5 and 2.7, respectively. Of land pests, willow is damaged by Chrysomela saliceti (0.7–7.2, in focuses 3.2–22.0 pests/plant), willow aphid (population score 1.1–1.8, in focuses 1.7–2.3), Hyponomeuta malinellus (population ratio 1.1–1.2, in focuses 1.8–2.1), Leucoma salicis (0.2–0.3, in focuses 1.9–6.1 larvae/plant), Chionaspis salicis (0.7–1.0, in focuses 2.3–10.0 individuals), Tetranychus urticae (population score 1.0–1.3, in focuses 1.4–2.3) and Philaenus spumarius, (0.1–0.8 in focuses 1.0–3.4 pests/plant). The control of the number of these plant feeders is carried out by soaking of cuttings before planting in insecticide solutions, as well as spraying the plants with chemicals against land pests.
 Conclusions. Energy willow plants are damaged by many species of soil and land plant feeders, the number of which depends on the area of growing. Controlling of their number is carried out by soaking cuttings before planting in insecticide solutions and spraying plants.