LIFE HISTORY OF RECURVARIA MILLERI, THE LODGE- 
POLE PINE NEEDLE-MINER, IN THE YOSEMITE 
NATIONAL PARK, CALIFORNIA 
By J. E. Patterson 
Entomological Ranger , Forest Insect Investigations , Bureau of Entomology , United 
States Department of Agriculture 
INTRODUCTION 
The lodgepole pine needle-miner (Recurvaria milleri Busck) infests the 
needles of the host tree, Pinus murrayana Oreg. Com., causing them to fade 
and later fall from the trees. The result is defoliation in the infested areas. 
Stands of timber affected by the needle-miner can not be distinguished 
superficially by the untrained woodsman from those infested by bark- 
beetles of the genus Dendroctonus. To prevent needless waste of timber 
and money, therefore, it is very desirable that control operations against 
barkbeetles, namely, the felling of the trees, should not be undertaken 
where only the less serious, and usually not fatal, needle-miner infesta¬ 
tion occurs. 
The only serious epidemics of the needle-miner which have been re¬ 
corded occur in the lodgepole pine stands of the Yosemite National Park 
of California. The studies presented in this paper were made in these 
epidemic areas during the summer seasons of 1917, 1918, and 1919. 
The investigations were confined exclusively to the Yosemite National 
Park, and the studies presented apply specifically to the insect in this 
locality only. 
HISTORICAL REVIEW 
In 1903 it was reported to the Bureau of Entomology through the 
Secretary of the Interior that large areas of lodgepole pine in the Yo¬ 
semite Park were affected by a leaf-mining moth. In May, 1904, Dr. 
A. D. Hopkins visited the Yosemite Park, planning to investigate the 
conditions which had been reported, but was unable to reach the lodge¬ 
pole pine areas, as all trails leading into the region were still closed by 
heavy snows. In 1906 Mr. H. E. Burke spent the month of July in the 
Tenaya Basin and Tuolumne Meadows, but found no evidence of the 
needle-miner in that vicinity, although a considerable amount of timber 
was being killed by the mountain-pine beetle (Dendroctonus monticolae 
Hopkins). Later, in 1907, Prof. J. H. Comstock reported its presence 
in the park to Dr. L. O. Howard, stating that he saw large areas of 
tamarack pine (as lodgepole pine is called locally) infested by the moths. 
Journal of Agricultural Research, Vol. XXI, No. 3 
Washington, D. C. May 2 ,1921 
xm Key No. K-94 
(127) 
