The Canadian Entomologist 132: 925 -937 (2000) We tested six behavioral chemicals, pityol, conophthorin, 4-allylanisole, verbenone, 2-hexenol, and a-pinene, in a series of field trials directed at six combinations of Conophthorus Hopkins -Pinus L. spp. (Pinaceae) Ait. trans-Verbenol was tested only on C . resinosae on P. resinosa. Traps baited with pityol caught more beetles than unbaited traps in nearly all of the assays, and conophthorin consistently inhibited male beetle response to pityol for all species tested. Behavioral responses of species of Conophthorus to a-pinene appeared to parallel host phylogeny, inasmuch as beetles using Haploxylon pines as hosts utilized a-pinene as a synergist for the beetle-produced pityol, whereas beetles using Diploxylon pines as hosts did not. a-Pinene was a synergist for pityol in C . ponderosae on P. monticola and C. coniperda on P. strobus, but not for species of Conophthorus on any other pines tested. Conophthorus ponderosae on P. ponderosa was the only beetle-host combination tested where verbenone was a synergist for pityol, but this effect was not consistent in all years of testing. It was also the only beetle-host combination in which 4-allylanisole was a repellent. For all otherAuthor to whom all correspondence should be addressed (E-mail: nrappaport@fs.fed.us). THE CANADIAN ENTOMOLOGISTNovemberPecember 2000 beetle-host combinations, verbenone was neutral to slightly repellent and 4-allylanisole was either synergistic or neutral in pityol-baited traps. Promising synergists and intermptants/repellents were identified for implementation in pestmanagement regimes, including conophthorin as an interruptant for all species of Conophthorus tested, 4-allylanisole as an interruptant for C. ponderosae on P . ponderosa, a-pinene as a synergist for pityol in all species tested on Haploxylon pines, and 4-allylanisole as a synergist for pityol in C. conicolens and C. coniperda. ResumeNous avons test6 six substances chimiques affectant le comportement, le pityol, la conophthorine, le 4-allylanisole, la verbhone, le 2-hexenol, et l'a-pinkne, au cours d'une sCrie de tests en nature sur six combinaisons de Conophthorus Hopkins -Pinus spp. (Pinaceae) en plusieurs endroits rkpartis dans toute 1'AmCrique du Nord. Les combinaisons colCoptkre -arbre-h8te ont Ct C les suivantes: Conophthorus ponderosae Hopkins sur Pinus ponderosa Laws., C. ponderosae sur Pinus monticola Dougl., Conophthorus conicolens Wood sur Pinus pseudostrobus Lindl., Conophthorus teocotum Wood sur Pinus teocote Schl. et Cham., Conophthorus coniperda (Schwarz) sur Pinus strobus L. et Conophthorus resinosae Hopkins sur Pinus resinosa Alt. Le trans-verbCnol a Ct C test6 seulement sur C. resinosae sur P. resinosa. Les pikges garnis de pityol ont capturC plus d'insectes que les pikges non garnis dans presque tous les tests et la conophthorine inhibait systkmatiquement la rCponse des miiles au pityol chez toutes les espkces testkes. La rCponse de toutes les espkces de Conophthorus a l'a-pinkne semble fonction d...