INSECT ENEMIES OF WESTERN FORESTS 85 
There are a large number of other budmoths and leaf rollers that 
infest the buds and young, tender leaves of various broadleaved 
trees and shrubs. This damage is often of a serious nature in 
orchards but seldom is of any importance in the forest. No attempt 
can be made to discuss these interesting but relatively unimportant 
species. 
NEEDLE MINERS 
Some leaf-eating insects have 
the habit of feeding internally 
on coniferous needles and thus 
protecting themselves within a 
thin, leafy covering. ‘These are 
called needle miners. <A great 
many of them cause only an in- 
significant amount of damage, 
but a few, such as the lodge- 
pole needle miner, may defoli- 
ate extensive areas and con- 
tribute to the destruction of 
the timber cover on entire wa- 
tersheds, as has happened in 
parts of the Yosemite National 
Park. The needle miners be- 
long mostly to one small genus 
of moths. 
Outbreaks of needle miners 
are eventually brought under 
control by the action of native 
parasites and the influence of 
climatic conditions. ,Direct con- 
trol through the use of the ordi- 
nary sprays or dusts offers 
httle hope of being effective 
since the insects work within 
their protective covering and 
would not be reached by these 
poisons. Recent experiments 
indicate that light, penetrating 
oul sprays to which nicotine has 
becteaddedmoticrepromiseof ©" “—Gymcric hives) © oon” 
being effective. 
The lodgepole needle miner (Recurvaria millert Busck) (66) 
(fig. 42) is the best representative of this group in the West. As its 
name implies, it mines the needles of lodgepole pine and is found 
through the lodgepole pine forests of the Sierra Nevada in California. 
It has defoliated extensive areas of lodgepole pine in the Yosemite 
National Park and so weakened the trees that they readily succumbed 
to the attacks of the mountain pine beetle. The adults are very small 
white or grayish moths only about one-half inch long. The cater- 
pillars are very small greenish worms with black heads. In the 
Yosemite National Park this species has a 2-year life cycle, the moths 
flying in alternate years, 
