Photos from the WFIWC Archives:
Control Methods

During 1956-1963, I conducted varied research on the Douglas-fir beetle on the South Fork of the Salmon R., Idaho. During 1959-1960, LeRoy Kline was my summer assistant. His MS thesis involved the temporal and spatial distribution of the beetle's natural enemies in infested trees. Another study that he assisted with was testing a 2% DDT spray for preventing infestation of downed trees by the DFB. In the NW USA, outbreaks occur when the beetle population is released in storm-damaged trees.(Furniss 1962)

A. LeRoy applying spray to a freshly felled stem section.

B. Bark sample showing "point attacks" on the inner phloem of a treated log. Attacking females died before constructing a gallery.

C. Normal galleries and larval mines in an untreated stem. The effectiveness of DDT was astounding but its adverse environmental effects on other life were coming to attention and use of this insecticide in the U.S. was banned in 1972.

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