Harmfulness of the viburnum leaf beetle (Pyrrhalta viburni Payk.) on plants of the Viburnum L. genus and elements of its control technology for strategies in breeding work in the system of fruit and decorative gardening

Abstract

The studies were conducted in various ecological points of Ukraine (western and northern part of the Forest-Steppe, Southern Polissia) to examine the bioecological features of Pyrrhalta viburni Paykull and develop measures to reduce its harmfulness in the system of fruit and decorative gardening. The purpose of the study was to examine the bioecological features of the viburnum leaf beetle on plants of the Viburnum L. genus and elements of its control technology (selection of species, varietal composition, seasonal pruning, mechanised trunk, or inter-bush loosening of the soil, application of mineral fertilisers, use of paraffin oil and Actofit biological product) for strategies in breeding work. The study was based on the use of the method of conducting a qualification examination, visual methods (route and detailed), the method of accounting and describing pests, determining the degree and score of infestation, and the percentage of damaged plants. As a result, species of the Viburnum L. genus are differentiated by susceptibility to viburnum leaf beetle into: susceptible – V. opulus, V. sargentii, moderately or poorly receptive – V. lantana, and immune or resistant – V. sieboldii, and in the garden conditions on moderately or poorly susceptible – V. opulusand V. sargentii and resistant – V. sieboldii and V. lantana. The most effective measure of mechanical control of the viburnum leaf eater, in particular, in the collection, hybrid, breeding, and queen nurseries, is pruning individual branches with pest eggs laid on them during November-March. It is identified that the appropriate measure is the formation of biological barriers in the breeding nurseries of Viburnum, represented by other viburnum species (Siebold’s viburnum, Viburnum lantana), which are less susceptible to the viburnum leaf beetle than the plants of Viburnum opulus or Viburnum sargentii, which will allow preserving valuable genotypes of the above-mentioned viburnum species from damage by the pest at an early stage and prevent the use of environmentally dangerous chemical pesticides. The results of the study expand information about the Pyrrhalta viburni Payk. species and can be used in the ecology of insect pests, the developed measures will allow controlling the populations of viburnum leaf beetle in the system of fruit and decorative gardening at an early stage