May 2,1921 
Life History of Recurvaria milleri 
141 
possibilities of control 
It is evident that the insects and other natural enemies of the moth 
have not been sufficient to maintain control on the greater part of the 
area involved in the epidemic. Artificial measures are at once suggested 
by the information now available relating to the various stages of the 
insect’s life history. 
The use of sprays, which is usually resorted to for the control of infesta¬ 
tion of this character, does not appear practicable for application through¬ 
out extensive forest areas where every tree is infested, because this 
method to be successful requires very thorough and frequent applications. 
Because of the peculiar life history of the species, however, contact sprays 
would be more valuable than stomach poisons since, during the egg and 
initial larval stage and before the young larvae have entered the tips of 
the needles, both eggs and larvae are exposed and contact sprays would 
reach them. Stomach poisons would be effective only when the larvae 
are eating their way into the needles. 
The infestation could also be attacked by felling the infested trees. 
During the feeding periods of the larvae the felling of the trees would 
cause the death of the needles and the larvae thus deprived of their food 
supply would soon succumb. This method, however, would call for the 
felling of every infested tree in the entire stands involved in the epidemics. 
For this reason the method is impracticable and can not be con¬ 
sidered except in the case of a few trees which might threaten a non- 
infested stand. Such situations, however, have not been observed in 
this epidemic. 
On the whole, it is doubtful if costs of applying any method of control 
against the moth would be warranted by the present value of the lodge- 
pole pine stands in the Yosemite National Park. This species has little 
commercial value, and even for park purposes it is not nearly so desirable 
as other species. 
These silvicultural features should be considered in any scheme of 
forest protection for the Yosemite National Park. In many sites where 
the mature lodgepole pine has been killed out by barkbeetle epidemics 
following in the wake of the needle-miner invasions, mountain hemlock 
and fir are reproducing to a most encouraging extent. These latter 
species are more desirable for park purposes in many ways and are not 
subject to the insect epidemics which are killing the lodgepole pine. It 
is the opinion of the writer that the great amount of funds which would 
be required for the protection of the lodgepole pine could be spent to 
better advantage to encourage the reproduction of more desirable species. 
