Efficacy of different lures for Phloeosinus aubei and other native and exotic bark and ambrosia beetles

Abstract

Phloeosinus aubei is invasive in Central Europe, spreading northward from the Mediterranean region because of climate change. P. aubei has the potential to become a pest of mature, naturally occurring juniper trees (Juniperus communis) in protected areas, as well as junipers, thujas and cypresses in nurseries and urban environments. In 2020 and 2021, we conducted two experiments to compare various lures for trapping P. aubei. In the first experiment, we compared four lures: α‐pinene; turpentine; a mixture of cade oil, juniper berry oil and ethanol; and a juniper branch (8–10 cm long, 3–5 cm wide) deployed with ethanol. In the second experiment, we compared Hostowit® with a juniper branch (8–10 cm long, 3–5 cm wide) deployed with ethanol. In both experiments, juniper branches deployed with ethanol attracted a greater number of P. aubei beetles compared to the other lures. In total, we captured 1056 individuals belonging to 36 species of Scolytinae. Among the most abundant species, Xyleborinus saxesenii, Xyleborus monographus and Anisandrus dispar were lured by ethanol in combination with other substances or deployed with juniper branches. Xyleborus dryographus showed a positive association with turpentine. Ips typographus was positively associated with α‐pinene, while Orthotomicus laricis, Hylastes attenuatus and Gnathotrichus materiarius were positively associated with Hostowit® lure.

A monitoring network for the detection of invasive ambrosia and bark beetles in the Czech Republic: principles and proposed design

“…Factoryproduced pheromones were suitable for trapping ambrosia and bark beetles of the genus Trypodendron; we found one specimen of X. germanus (Fiala and Holuša, 2020). Among volatile substances, we found the best combination of ethanol and juniper twigs suitable for trapping bark beetles P. aubei (Fiala et al, 2023). We found ethanol to be the most suitable for G. materiarius (Fiala et al, 2023).…”

“…A total of three species of BB, Cyclorhipidion bodoanum, Gnathotrichus materiarius, and X. germanus, were captured (Inward, 2020). (Knížek, 1988;Procházka et al, 2018;Fiala and Holuša, 2019;Fiala et al, 2020Fiala et al, , 2021Fiala et al, , 2023. Furthermore, several introduced species that could not form a stable population due to an unfavorable climate or absence of host plants were found in the territory of the Czech Republic: Coccotrypes dactyliperda Fabricius, 1801, Hypothenemus areccae Hornung, 1842, Hypothenemus hampei Ferrari, 1867, Hypothenemus setosus Eichhoff, 1868, Xyleborus affinis Eichhoff, 1868, Xyleborus volvulus Fabricius, 1794, and Xylosandrus morigerus Blandford, 1894 (Reitter, 1913;Fleischer, 1927Fleischer, -1930Pfeffer and Knížek, 1989).…”

“…Since 2020, efforts have been underway to determine the possible entry gates and directions of expansions of BB in the Czech Republic (Figure 1; Fiala and Holuša, 2019;Fiala et al, 2020Fiala et al, , 2021Fiala et al, , 2023. Potential types of volatile substances that could be used for monitoring were compared to find the simplest monitoring method (Fiala and Holuša, 2020;Fiala et al, 2023).…”

“…This is logical because most of the BB in Europe have been detected near seaports in western and southern Europe. The main entry points were clearly identified as river valleys and border crossings (Fiala et al, 2020(Fiala et al, , 2023.…”

“…Therefore, it is necessary to create a stable network of traps for monitoring invasive species of ambrosia and bark beetles. To determine the methodology, several experiments were carried out in the Czech Republic, providing basic knowledge about the spread of BB and their bionomics in the Czech Republic Holuša, 2019, 2020;Fiala et al, 2020;Holuša et al, 2021;Fiala et al, 2023).…”