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

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.