Vectors of Dutch Elm Disease in Northern Europe

Potential Dutch elm disease vector beetle species were caught with pheromone bottle traps and handpicked in 2019: in total, seven species and 261 specimens were collected. The most common was Scolytus triarmatus, but by percent, the incidence of Ophiostoma novo-ulmi was highest in Scolytus scolytus, followed by Xyleborinus saxesenii and S. triarmatus. We analysed the beetles’ DNA using PacBio sequencing to determine vector beetles of Ophiostoma novo-ulmi. Ophiostoma novo-ulmi was found on six out of seven analysed beetle species: Scolytus scolytus, S. triarmatus, S. multistriatus, S. laevis, Xyleborinus saxesenii and Xyleborus dispar. The last two beetles were detected as vectors for Ophiostoma novo-ulmi for the first time. Previous knowledge on the spread of beetles is discussed.

Protection of intensive apple orhards from phytophages complex in steppe zone of Ukraine

According to long-term surveys of apple plantations in Ukraine, they are da maged by an unpaired western bark beetle (Xyleborus dispar F.). The share of this pest colonizing perennial plantations in Ukraine is about 30%, and there is also a tendency of spreading colonization of this type of production tracts over fruit plantations. The prevalence of bark beetle in production areas of orchards has increased significantly in recent years. Unpaired pest, unlike many other species of bark beetles, completely destroys healthy trees. The increase in the number and harmfulness of odd western bark beetle is associated with climate change, the use of various protection systems, etc. Nowadays measures to reduce the number of this species consisted only of a mechanical technique (cutting and burning dam-aged trees) and spraying of garden plantings in the phase of “swelling of the buds ‒ beginning of budding” with old insecticides of second generation (metaphos, chlorophos, carbophos, etc). Pruning and burning damaged trees are an ineffective measures to reduce the number of pests in orchards. The expediency of testing a number of modern insecticides is urgent and effective against a complex of phytophages in the “green cone” phase ‒ “ Rose bud” (beetle, goose, budworm, apple blossom beetle, aphids, leafworms) ‒ “end of flowering” (leafworms, aphids) and can be effective against the western unpaired bark beetle. The basis was the du-ration of action and the peculiarities of the mechanism of action of these insecticides (contact intestinal action ‒ Aktara 240 SC, HP, Mospilan, P. P., Calypso 480 SC , etc. and contact, par-tially systemic action with fumigation effect ‒ Bi‑58 new, etc., Pirinex Super, etc., Danadim stable, etc., Danadim Mix, etc., Fufanon 570, etc.). The use of the drugs mentioned above (for double treatment of plantings) demonstrated high technical efficiency against openly living phytophages (for the first treatment of plantations ‒ against aphids, leafworms, garden wee-vils and tube worms, for the second treatment ‒ against aphids, leafworms), which amounted to 91,3‒99,2%. The western unpaired bark beetle (Xyleborus dispar F.) is a permanent species in the industrial areas of the apple tree. And therefore, protecting trees from it in industrial plantings should be an integral part of modern technology for obtaining fruit products. Un-doubtedly, the application of the complex of insecticides Bi‑58 new, к.е. (2,0 l/ha), Pirinex Super, к.е. (1,25 l/ha), Danadim stable, etc. (2,0 l/ha), Danadim Mix, etc. (2,0 l/ha), Fufanon 570, E.C. (2,0 l/ha) is a highly effective method for reducing the harmfulness of the western unpaired bark beetle in industrial plantations of apple trees, an economically beneficial meth-od in the modern intensive protection technologies.

КОМАХИ-КСИЛОФАГИ ЛИСТЯНИХ ПОРІД У НАЦІОНАЛЬНОМУ ПРИРОДНОМУ ПАРКУ «ГОМІЛЬШАНСЬКІ ЛІСИ»

The aim of the research was to determine the ecological features and to evaluate the harmfulness of the most common xylophagous insects at the territory of the National Nature Park «Gomilshansky Forests». In deciduous forests of the National Nature Park «Gomilshansky Forests», 22 species of xylophagous insects from 16 genera of three families have been found, i.e. longhorn beetles (Cerambycidae), jewel beetles (Buprestidae) and bark beetles (Curculionidae: Scolytinae). The vast majority of species are polyphages. Five species (Xylotrechus antilope, Agrilus biguttatus, A. hastulifer, A. laticornis and A. sulcicollis) were found only in the English oak, Dicerca (Dicerca) aenea was found only in the elm, and other xylophagous insects were found in different deciduous trees. The jewel beetle Agrilus biguttatus, the bark beetles Scolytus intricatus, Xyleborus dispar, Xyleborus monographus and Xyleborinus saxeseni colonized the most vital trees. The longhorn beetle Anisorus quercus colonized drying up trees, and the longhorn beetles Poecilium alni and Prionus coriarius colonized only dead trees. Potential injuriousness of each species was evaluated considering both physioogical injuriousness and technical injuriousness. Four species (18.2 %) – A. biguttatus, S. intricatus, Xyleborus dispar and Xyleborinus saxeseni – are potentially the most harmful with the frequency of occurrence 7 %, 5 %, 1 %, and 1 % respectively. Among 9 moderately harmful species (40.9 %), the most spread are Plagionotus arcuatus, P. detritus and Saperda scalaris (11 % each). Slightly harmful are 5 species, or 22.7 %, harmless are 6 species, or 18.2 %. The data obtained are the basis for further comparing the species composition and harmfulness of xylophagous insects in the zones with different management regimes of the national nature park.

Sudden Occurrence and Harmfulness of Xyleborus dispar (Fabricius) on Pear

Summary Decline of pear trees in the region of Čačak (Serbia) is becoming a significant problem and a limiting factor in the production of this fruit species. This phenomenon may be due to the damages caused by xilophagous insects, representatives of the family Scolytidae. Economically the most important species of this family is a pear blight beetle (Xyleborus dispar), which causes symptoms of decline and/or wilting of pear trees. Such damages have not been documented so far in the region of Čačak. The aim of this study was to determine the cause of sudden appearance of pear trees decline in an orchard in this region (locality of Miokovci). The orchard has 180 trees (Stark Delicious, Santa Maria and Williams) in the sixth year of vegetation. Inspections were carried out every 30 days (20 April - 21 August 2016). Visual inspection identified X. dispar activity on 165 trees (about 92% of the trees in the orchard). Holes were registered on the trees up to a height of 160 cm and in all primary branches. The average number of entry openings on a random sample of 20 trees was 27 for the height from the soil surface to the first branch (70 cm), while it was 61 for the height up to 160 cm. The recommended treatment is eradication of pests with mandatory incineration (burning) of the collected plant material by the end of February of the following growing season. This is the first report of X. dispar as pear pests in the vicinity of Čačak.

Investigation of European shot-hole borer, Xyleborus dispar (Coleoptera, Scolytidae), in apple orchards of Latvia

European shot-hole borer is known to occur on a wide range of deciduous trees and frequently found on fruit trees in most of the Holarctic. During the last years increased activity of this beetle<em> </em>contributed necessity for investigation of it in apple orchards of Latvia. Because of the latent behavior it is difficult to control distribution of <em>Xyleborus dispar</em>. Often insecticides are not effective, especially if not used in an appropriate time and methods of integrated or biological plant protection are needed. In the current study, results of two year monitoring of <em>X. dispar</em> flying activity and effectiveness of two types of sticky traps, Rebell Rosso and Csalomon Palx, bitted with 50% alcohol are presented. Four traps of each type were placed in each orchard at the beginning of May in 2013 and at the middle of April in 2014. Differences among respective orchards were recorded: the highest number of beetles was found in the largest orchard surrounded by wide deciduous forests; the lowest number was recorded in the orchard surrounded by the agricultural lands. The first emerging <em>X. dispar</em> female was caught at the middle of April. During the vegetation season the highest flying activity of beetles was at the end of April - beginning of May (17^th – 18^th week). Afterwards number and flying activity of beetles decreased and at the middle of June (25^th – 26^th week) reached zero. In orchard with the highest number of European shot-hole borer, significantly higher number of beetles was recorded on Rebell Rosso traps; for the rest two orchards higher number of <em>X. dispar</em> was recorded on Csalomon Palx traps.