Field Bug Crew. L-R: Walter J. Buckhorn, D. Lynch, F.P. Keen, J. Kapitke, and T. Parr.

Photo by: Unknown Date: 1932

Credit: USDA Forest Service, Pacific Northwest Region, State and Private Forestry, Forest Health Protection. Collection: Bureau of Entomology, Portland Station Collection; La Grande, Oregon. Image: PS-6003

To learn more about this photo collection see: Wickman, B.E., Torgersen, T.R. and Furniss, M.M. 2002. Photographic images and history of forest insect investigations on the Pacific Slope, 1903-1953. Part 2. Oregon and Washington. American Entomologist, 48(3), p. 178-185.

Note: From the September 1932 Forest Worker: "Pine Beetles Killed by New Method By F. P. Keen, Bureau of Entomology, and Frank Solinsky, National Park Service, in charge of insect control, Crater Lake National Park.

More effective and cheaper methods of killing pine beetles are constantly being sought by entomologists and foresters who have to deal with these destructive timber pests. The use of oil by the United States Forest Service in national forest Regions 1 and 4 in burning the bark of standing or felled lodgepole pines infested with the mountain pine beetle led to the adaptation of this method in treating infestations in the Crater Lake National Park. After many trials with different oils, equipment, and modes of application, the following practice was adopted.

In the Crater Lake Park most lodgepole pines are too tall for the infested length to be burned without felling. The trees were felled in such a position as to raise them off the ground and clear of brush and green timber. They were then limbed, and the top cut off at the end of the infestation. A small fire was started on the base of the log, a spray stream of oil directed against it, and the fire carried up one side of the bole and down the other. The log was then given a quarter turn, and the unburned sides treated in the same way. One man with a shovel followed the burner and extinguished any fire that dropped to the ground. By never allowing any ground fire to start, the escape of fire and scorching of near-by trees was almost entirely avoided. As in the similar work on the national forests, it was considered that the log had been adequately burned when the bark scales showed white ash margins. Within 5 or 10 minutes the fire was completely out, only the bark was scorched, and the beetles were killed.

The burning equipment used in the project consisted of a 5-gallon back-pack pump, similar to the standard pump required for fire protection, fitted with a 3-foot extension and a nozzle designed to vary the character of the oil stream. Several S-gallon cans were necessary for transportation of oil to replenish the pump. Ordinary fuel oil with a gravity of 27 and a flash point of 225° F. was found to be the most satisfactory both from the standpoint of slowness of burning and cost.

It was found that five men made the most economical size of burning crew — two fallers and three burners. The burners interchanged positions, alternately burning, extinguishing fires, and packing oil in order to equalize the burden of the various jobs. The cost of the project varied from 68 cents to $1 per tree, depending upon the thickness of the ground cover, the extra fire precautions which had to be taken, the distance from the oil supply, and the ability of the crew to adapt the method to each particular situation. At about 5 cents per gallon, the cost of the oil used per tree was almost negligible, one-half to three-fourths of a gallon being sufficient.

In places where the stand is open and the trees are relatively short and have thin bark, the burning-standing method of beetle control can be used. It can probably be used in Crater Lake Park to good advantage in the treatment of short, thick, and knotty whitebark pines which are very difficult to fell and peel.

The oil-burning method was also tried by national park officers in the treatment of ponderosa pine infested with the western pine beetle. When the amount of oil used on the stems of felled trees was increased the bark and cambium layer became so hot as to burn one's hands when touched, and all of the beetles in and under the bark were killed. The results were so successful and the cost so greatly reduced in comparison with the old hand-peeling and burning that the method may find an important place in the control of the western pine beetle in ponderosa pine as well as in combating the mountain pine beetle in lodgepole pine stands." <a href="https://archive.org/stream/CAT11088243_049/CAT11088243_049_djvu.txt" rel="nofollow">archive.org/stream/CAT11088243_049/CAT11088243_049_djvu.txt</a>

For additional historical forest entomology photos, stories, and resources see the Western Forest Insect Work Conference site: <a href="http://wfiwc.org/content/history-and-resources" rel="nofollow">wfiwc.org/content/history-and-resources</a>