Previous researchers, have speculated or concluded thatCoeloides brunneri Viereck females detect their bark beetle hosts by perception of the vibrations or sound made by boring larvae. However, when placed on logs containing various actively mining stages ofDendroctonus pseudotsugae Hopkins,C. brunneri females actively searched for the host only on logs infested with young or maturing brood larvae, and oviposited only in logs with maturing brood larvae. Moreover, when offered larvae in logs that had been frozen at approximately − 50°C, and then allowed to thaw at room temperature for 2 days, they found the motionless, dead larvae, and oviposited through the bark on to them. Therefore,C. brunneri is able to find ist host by perception of some stimulus (or stimuli) other than sound or vibration.