CRATER LAKE Report: Battle Against Bark Beetles

The letters between Craighead and Keen were numerous during spring 1932. Keen was sending weekly reports on the progress of the work to a worried Craighead. The letters commented on difficulties of doing the treatment in deep snow and burning some trees with oil rather than using the solar method. [37] Keen was continually optimistic, however, that they were on the verge of making a thorough cleanup of the park infestation that year. A last-minute push by Park Service and Forest Service crews cleaned up the infestation around Mount Scott, but the virulent outbreak in the Sun Pass basin continued and no control work was being carried out there in 1932. Craighead closed the June correspondence [38] by saying,

I was somewhat surprised at your remarks concerning the Sun Pass infestation. I did not realize that it was so virulent. I too feel that conditions reported within the Park control areas are clearly due to the effects of control. If there was some way to estimate bugs rather than trees the effect of the work already done would be much more pronounced than it is on a tree basis when partially infested trees have to be treated.

On November 12, 1932, Keen sent Craighead a copy of his report on the 1932 activities. In the transmittal letter Keen said, "There was nothing much to report about this situation this year except the good news that the beetles have finally been brought under control, and nothing more is needed except a small yearly maintenance program until stable conditions have been definitely restored." [39]

Keen reported 20,311 trees treated at a cost of $17,357. On the old control units, the reduction in infested trees from 1931 to 1932 was 74 percent. [40] In the report Keen stated, "The goal of the mountain pine beetle control campaign in Crater Lake National Park has finally been reached with the completion of the work of this year. All of the aggressive infestation in and adjacent to the southern half of the Park has been disposed of, and the fall cruises show that there are no longer any active centers in this entire area." He warned that beetles might still invade the park from the Sun Pass area, but his final recommendation was for the Park Service to treat about 5,000 trees in the old control units and the Forest Service to treat 22,000 trees in the Sun Pass area. He called the Park Service work "maintenance control" and thought it would be necessary for only a few seasons (see footnote 40). A report by Frank Solinsky, in charge of control work for the Park Service, referred to the deep snow pack that persisted well into June, thereby slowing Control work. He also noted a week or more of cold snowy weather in mid-July that slowed the work further. And he commented favorably on the new development of oil burning infested trees in shady areas where the solar method was not effective. He stated that over 100 men were employed in the bug camps that year by the Park Service. [41]

Craighead closed the year with these comments in a November 29, 1932, letter to Keen: [42]

Your report of the present status of the Crater Lake control project transmitted with your letter of November 12 is most encouraging. It finally looks as though we have got the upper hand of this job. Indications are that nothing further will be necessary for the next few years except some maintenance work, provided the Sun Pass infestation on the National Forest does not get out of hand. Obviously it is a toss-up whether or not this will spread into the Park. I am afraid that when the infestation reaches a certain degree of intensity it is going to serve as a source of reinfestation of the park land. This danger will necessitate annual surveys of the Park timber for the next few years and some action will have to be recommended if there is an obvious reinfestation of the cleaned area.

I believe that the work in the past two years on this project shows quite definitely that this beetle can be controlled when funds are available for thorough work and where flight from the outside is not a factor. I can not help but feel from the experience of the past few years that thorough initial work is the key to the success of many of these beetle control projects and in different work, although not intentionally so. is the explanation for some of the poorer results which have been so disconcerting.

Figure 19—Another type of treatment used in shady areas was to peel the bark from the tree with a spud thus exposing the bark beetle brood and killing it, 1947, Crater Lake National Park.

The "maintenance" control work in 1933 marked the first use of Civilian Conservation Corps (CCC) crews in insect control in the park. The men arrived from the east just as control work was to begin, and eventually 200 young men were treating trees. Even though they lacked experience using tools and working in the woods, they were given high praise by Frank Solinsky for their eagerness to learn and willingness to work hard to prove themselves. [43] The Park Service treated 7,026 trees that season in the old units. Most of the trees were killed by mountain pine beetle, but over 100 trees were mountain hemlock (Tsuga mertensiana (Bong.) Carr.) and white fir (Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.) killed by other insects (see footnote 43). Solinsky also noted that the Sun Pass infestation was not treated for the second year in a row because of a lack of funds. He also noted that very cold temperatures during the winter 1932-33 caused mountain pine beetle brood mortality in the park and at Sun Pass. Temperatures recorded at the park were -14°F in December and -16°F in February—enough to kill at least some insects under the thin-barked lodge pole pine. Solinsky thought that only 1,000 trees would need treating in 1934 (see footnote 43).

Correspondence for 1933 indicates that neither Keen nor Buckhorn participated in the control work that spring. They were evidently busy moving their office and laboratory in Portland, OR, and doing research on western pine beetle in other areas. Patterson also rejoined the Bureau of Entomology that summer and was put in charge of CCC insect control for the Stanislaus National Forest in California. He promptly got Frank Solinsky a job at the Stanislaus for the remainder of that season as a bug spotter. [44] The end of the season found Keen and Craighead visiting the park and finding very few infested trees. They noted that perhaps the CCC crews could treat the Sun Pass area and finally end that threat to the Park. [45]

By 1934, only 21 lodgepole pine infested with mountain pine beetle were treated. The battle was finally over. A survey of the old control areas in the park by Buckhorn in October 1934 found less than 500 infested trees, and over half of these did not have enough brood to justify treatment. He recommended that no control be under taken in 1935 against mountain pine beetle except in recreation centers. [46] Buckhorn did report that the Sun Pass infestation, though reduced by winter kill of beetle broods in 1932-33, had rebounded in 1934. That spring the Forest Service treated nearly 6,000 trees by using CCC crews. Buckhorn recommended that the estimated 2,000 trees infested in fall 1934 be treated in 1935 to stamp out this infestation (see footnote 46).