The attractant aggregation pheromone of the northern spruce engraver, Ips perturbatus (Eichhoff), consists of ipsenol, ipsdienol, and cis-verbenol.  These pheromone components were identified by GC-FID and GC-MS from Porapak Q and abdominal tissue extracts, elicited responses in GC-EAD assays, and were attractive in the field in Lindgren funnel trap assays (Holsten et al. 2000).  In two field behavioral assays of these and other semiochemicals, over 59, 000 I. perturbatus were trapped at one site in south-central Alaska (Kenai Peninsula) and nearly 62,000 I. perturbatus were trapped at a second site in interior Alaska (near Tok).  At both sites the highest response was to the three-component attractant  (mean=203/week, Granite Creek; mean=363/week, Tok), and the response to attractant was interrupted in descending order by enantiomerically pure (+)-verbenone, conophthorin, enantiomerically pure (–)-verbenone, and commercially available [84% (–)]-verbenone. When commercially available verbenone was combined with conophthorin, the flight response of I. perturbatus was reduced by 27X (Granite Creek) and by 37X (Tok) (means=7.5/week and 9.75/week, respectively).  Dissection of genitalia revealed that during the first week of flight (May 26-30, 2001), the I. perturbatus that responded at Granite Creek were approximately 50% male, and there was no apparent treatment effect on the percentage of males responding.  Two species of Scolytidae and one species of Colydiidae also responded in large numbers to the treatments.  At Granite Creek, over 4,200 specimens of the twig beetles, Pityophthorus nitidulus Mannerheim and P. recens Bright were attracted primarily to conophthorin-baited traps. These species have been collected in this area under the bark of branches of Lutz spruce, Picea  xlutzii, infested with I. perturbatus.  At Tok, nearly 1,300 specimens of the cylindrical bark beetle, Lasconotus borealis Horn also responded primarily to treatments containing conophthorin.