Nature Notes

Volume III No. 3 - September, 1930

The California Tortoise Shell Butterfly
By H. A. Scullen, Ranger Naturalist

Many visitors to Crater Lake National Park during the past month have had their attention brought to the large number of butterflies flying in and through the park, and often becoming troublesome on the radiators of automobiles.

The California tortoise shell (Vanessa californica Behr.) is the name applied to the species which is most commonly seen. They may be seen in great numbers from the Transitional Zone to the highest points in the Hudsonian Zone where they are most common about moist places, but are often seen flying by the thousand in one direction, apparently heading for a definite place. The following day, or even later in the same day, they are found moving in the opposite direction. The larvae of this species feed on several of the wild shrubs of the mountains, and often do considerable damage in this way.

Bugs -- Part III
By Earl U. Homuth

In 1929 a sum of approximately $17,500 was expended in the work of control. This included a deficiency appropriation. An item of great expense was that of transportation. It was necessary to transfer all supplies from trucks to caterpillar tractors some twenty to thirty from the actual scene of work. This was greatly reduced in 1930, since snow plows had been acquired and the roads were kept clear, and supplies brought directly to the work on trucks.

In 1929 twenty-three thousand five hundred forty-four trees were treated. These covered an area of six thousand fifty-five acres, or an average of approximately four trees per acre. The work for that year covered the period from May 10 to July 8. This in itself indicates the intensity with which the work must be advanced. Beetles may by that date be observed in the forest, and since the object of the process is to destroy them before they have matured in the trees, any further work is useless.

In 1930 the appropriation was $7,500. As mentioned, less was expended for the formidable item of transportation. This year 9850 trees were cut over an area of four thousand three hundred acres. This gives an average of 2.28 trees per acre. The period of work was May 13 to July 9 when again mature beetles were found, and the operations of necessity suspended.

An interesting fact developed when the final figures were studied. Due to various factors, including lack of time and funds, an area (denoted as area "N") was not treated in 1929. In 1930 the percentage of infected trees in all areas excluding area "N" was 26%, and these were scattered. In area "N" the percentage of infected trees was found to be 65%. This accidental check on conditions gives a rather encouraging indication that the work is succeeding.

The average number of trees cut by a Falling crew per working day is 43. A competition developed between several crews this year and individual days cuts mounted until an almost unbelievable high record was established by one crew, of 137 trees cut in one day. This might well be included in "Believe it or Not" by Ripley.

National Park areas are preserved in as far as possible in their natural conditions. An infestation of any kind might be considered as a natural condition to be allowed to run its course. A forest fire due to lightening is also a natural condition, yet the argument would hardly be presented, that a forest fire due to any cause should be allowed to destroy our forests. A tree attacked by the mountain pine beetle in 90% of instances, is a dead tree in time. Therefore if by destroying that tree all others may be preserved, the effort and sums expended are justified. If by destroying thousands of trees, all trees in this and other states are preserved, with their scenic and commercial value considered, then the sacrifice is unquestionably justified and the success of the method developed in Crater Lake National Park is of importance far beyond the possibility of calculation.

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