The flight of bark beetles covers a short but important period of their life cycle, during which they are exposed to conditions not encountered during the major portion of their life under the bark. The time of flight and the factors which affect it are important, not only to the dispersal and survival of the insect, but also in the interpretation of experimental data dependent upon the beetle's flight activity.Chapman (1954), Rudinsky and Vité (1956), and Atkins (1959, 1960, 1961) studied the flight of the Douglas-fir beetle under laboratory conditions, but there is scant reference to field studies on the flight of this insect. Chapman and Kinghorn (1958) recorded the number caught in window flight traps near Cowichan Lake, B.C., and unpublished reports describe emergence records obtained from cage studies conducted near Lumby, B.C.