A preliminary study made by the U.S. Bureau of Entomology in 1924 indicated that infestation had wrought havoc throughout an area of some thirty square miles of lodgepole pine north of Crater Lake. The destruction had begun ten years before in the stands surrounding Diamond Lake and had subsequently spread southward toward Crater Lake. Thus, thousands of dead trees marred the forest vista and constituted a grave fire hazard in the northern and northeastern sections of the park. Since the infestation was spreading, immediate control measures were recommended both in the park and the surrounding forest reserves. [16]
An insect-control program, known as the Crater Lake Park. Control Project, was initiated under the direction of J. E. Patterson, Assistant Entomologist of the U.S. Bureau of Entomology, during 1925-27 under a special congressional appropriation. Two species of bark. beetles were targeted by the project–the mountain pine beetle attacking lodgepole pine and the western pine beetle attacking yellow pine, with the major operations being directed against the former.
Prior to the project it was determined that some 22,000 acres of the park lodgepole pine forests north of Crater Lake had been infested. Control work was not conducted on that area, however, because a high percentage of the trees had already been killed. Rather the control work. was concentrated on the 8,000-acre infested area of lodgepole pine south of Crater Lake in Pinnacles, Kerr, and Munson valleys, and Anna Spring vicinity. A total of 9,696 lodgepole pine and 43 yellow pine were treated. The solar heat method of control (felling infested trees, lopping off limbs and exposing bark to direct sunlight, thus killing the larvae and beetles in the bark.) was used to treat the lodgepole pines, while the yellow pines were treated by burning the infested bark in pits in the ground. The project resulted in checking the infestation south of Crater Lake and saving approximately 12,000 lodgepole pine trees. [17]
The insect control program resumed in 1929 because infestation epidemics outside the park boundaries were spreading into the park. Funds were transferred to Crater Lake from appropriations for Mesa Verde, Rocky Mountain, and Yellowstone national parks to undertake the work. In 1928 it was estimated that there were in the park 33,920 acres of dead lodgepole pine forest, 7,100 acres of active and epidemic infestation, and 15,360 acres uninfested. During the period May-July 1929 some 23,239 trees were treated for mountain pine beetle infestation in the Pinnacles Valley, Munson Valley, Anna Spring, Castle Creek, and Anna Creek. (Middle and East Forks) areas of the park.[18]
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