Dose-Dependent Pheromone Responses of Ips pini, Orthotomicus latidens (Coleoptera: Scolytidae), and Associates in Stands of Lodgepole Pine

We conducted four behavioral choice tests in stands of mature lodgepole pine in British Columbia, from 1988 to 1991, to determine the dose-dependent responses of Orthotortzicw 1atid;ns (1,eConte) and Ips pini (Say) to their respective pheromones. Dose-dependent responses were exhibited by I. pini to (5)-ipsdienol and lanierone, with trap catches directly proportional to pheromone release rates. We found differences in sex ratio of I. pini in their responses to ipstlienol but not lanierone. There was no close-dependent response exhibited by 0 . latidcns to its pheromone, ( i) -ipsenol, with or without the presence of the host kairornone, ( ) -/3-phellanctrene. The bark beetle predator, Er~ock.rus k(<contei (Wolcott), showed a close-dependent response to lanierone. T~uzr~asimz~s inrlntuh~s (Say) was attracted to ipsertol in a dose-dependent fishion orlly when traps were also baited with p-phellandrene. Neither T. undntu1r1.s nor E. . ~ ) I ~ ~ c I L s (F.) exhibited dosedependent responses to ipstlienol.