. Cooperative economic insect report. Beneficial insects; Insect pests. - 1005 PACIFIC NORTHWEST Highlights 1. The trend of spruce budworm infes- tation continued downward on all areas except the Fremont National Forest in southern Oregon. No aerial spraying will be done in I960. 2. The Douglas-fir beetle outbreak in southern Oregon declined, and should sub- side further in I960. In southwestern Wash- ington, this beetle attacked windthrown timber extensively and will probably spread to green timber in the spring. 3. Tree-killing by the we stern pine beetle varied. The Yakima Indian Reservatio
. Cooperative economic insect report. Beneficial insects; Insect pests. - 1005 PACIFIC NORTHWEST Highlights 1. The trend of spruce budworm infes- tation continued downward on all areas except the Fremont National Forest in southern Oregon. No aerial spraying will be done in I960. 2. The Douglas-fir beetle outbreak in southern Oregon declined, and should sub- side further in I960. In southwestern Wash- ington, this beetle attacked windthrown timber extensively and will probably spread to green timber in the spring. 3. Tree-killing by the we stern pine beetle varied. The Yakima Indian Reservation and adjoining areas contained the only serious infestations. 4. Outbreaks of the mountain pine beetle flared up in young stands of ponderosa pine in various parts of the region. 5. Tree-killing by the balsam woolly aphid decreased in Oregon but the aphid populations increased, indicating a recur- rence of heavy kills in the future. 6. The European pine shoot moth was discovered for the first time in the Pacific Coast States. Ornamental pines in the vicinity of Seattle, Washington, were in- fested. Trend of Douglas-Fir Beetle Down in Ore- gon and Up In Washington The widespread outbreak of the Douglas- fir beetle, Dendroctonus pseudotsugae Hopk., on and near the Siskiyou, Rogue River, Umpqua, and Siuslaw National Forests in southern Oregon declined from the peak reached in 1958. Tree-killing is significant on ap- proximately 325,000 acres but inspections in June showed light attacks and poor brood development, indicating a continuing downtrend in population. In southwestern Washington, broods are developing in timber that was windthrown over a wide area in 1958 (fig. 2) and many green trees will probably be killed in I960. While many of the broken and uprooted trees on the Snoqualmie National Forest and adjacent private lands have been salvaged, efforts by public and private agencies must be continued to prevent increased tree-kills in other areas. Smaller outbreaks centered o
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