The data are from two field experiments, one in New Brunswick, Canada and the other in Ås, Norway, assessing the response of heterospecific bark beetles and associated predators to the pheromone blends of two exotic species (Ips typographus in Canada, Dendroctonus rufipennis in Norway). Data are counts of relevant beetle taxa that responded to a variety of semiochemical treatments placed in multi-funnel traps using a randomized block design. Other taxa not included in the dataset were captured but were filtered out if they were present only in very small numbers (median counts of zero across all treatments) or were not ecologically relevant. The 'Block' column specifies the block number The 'Treatment' column species the treatment designation. It will be one of: Control: no semiochemical treatment Host: α-pinene and ethanol Ipslure: commercially available Ips typographus lure (Ipslure®; methylbutenol, cis-verbenol, and ipsdienol) plus α-pinene and ethanol DRlure: commercially available Atlantic Dendroctonus rufipennis lure (Synergy Semiochemicals Corp., Burnaby, BC, Canada; frontalin and seudenol) plus MCOL, α-pinene and ethanol The remaining columns are counts of all selected taxa across every combination of block and treatment group, with the column header being the taxa name (genus or species).