Volatiles from hosts, non-hosts, interspecifics and conspecifics of the Asian larch bark beetle, Ips subelongatus Motsch., were analyzed using both gas chromatographic-electroantennographic detection (GC-EAD) and GC-MS techniques, and field trapping bioassays in Inner Mongolia, China. GC-EAD experiments indicated that I. subelongatus antennae (both sexes) strongly responded not only to the major male-produced conspecific components, ipsenol and ipsdienol, but also to other bark beetle compounds (cis-verbenol and verbenone), host monoterpenes (á-pinene, â-pinene and para-cymene) from Larix sp. logs, and non-host leaf (green leaf volatiles and geranyl acetone) and bark (C8-alcohols and trans-conophthorin) volatiles. Repeatable EAD responses were also found to two compounds from hindgut extracts that are undetectable by GC. One of these minor compounds was identified as amitinol, while the other remains unknown. Field trapping experiments showed that the EAD-active, major male-hindgut component, racemic ipsenol, is the only individual compound that significantly attracted both sexes of I. subelongatus, while all other compounds, including previously reported pheromone components of European I. cembrae: ipsdienol and 3-methyl-3-buten-1-ol, were unattractive. Ipsdienol, 3-methyl-3-buten-1-ol or their binary blend had no synergistic or antagonistic effects on I. subelongatus attraction when combined with ipsenol, while cis-verbenol (the interspecific synomone) and verbenone (the antiaggregation pheromone) significantly inhibited its attraction to the ipsenol-containing attractive blend. A mixture of three EAD-active host monoterpenes, á-pinene, â-pinene and para-cymene, was unattractive, but interrupted the pheromone response of I. subelongatus. Geranyl acetone, one of the strong EAD-active non-host volatiles also significantly reduced the number of I. subelongatus captured in traps baited with ipsenol-containing attractive blend. Our results add new support to the recent phylogenetic finding that European and Asian larch bark beetles are two distinct species: I. cembrae infecting larch in Europe and I. subelongatus infesting larch in Asia.