
17 
June, the whole of July, and the first half of August could be remedied 
only in another season. 
Elaborate observations were made upon this August brood in 1895, 
the individuals of which were present in extraordinary numbers. Cer- 
tain of the larve under observation, which hatched on August 2, com- 
menced to spin upon September 3, and on September 14 the first male 
moths made their appearance, the first females issuing September 19. 
During the latter part of September the bulk of the moths issued, and 
the conspicuous white egg masses were very abundant by the 1st of 
October. Many of these egg masses were kept under observation from 
that time on. In the cold room of the insectary (temperature the same 
as outdoors) a few eggs hatched about the close of the second week in 
October, and on October 23 two newly hatched larve were observed 
upon an egg mass collected out of doors. This late fall hatching, how- 
ever, is probably exceptional, but in a late, warm autumn it is likely 
to be rather general. It is hardly to be supposed that any individuals 
hatching after the lst of October will successfully transform. The 
cocoons of this late fall generation are almost invariably spun upon 
the trunk of the tree and in the crotches of the main limbs, but occa- 
sionally, in the case of large trees, upon the larger limbs themselves. 
The tendency of all the larve of this generation is to crawl toward the 
ground before transforming. Cocoons ‘are occasionally spun upon 
fences or other objects near the trees upon which the larvee have been 
reared, but the vast majority are found upon the trunks. 
There are, then, certainly two, and probably three, annual genera- 
tions at Washington.' In New York and Brooklyn there are two 
well-marked generations. At Boston, as is learned from Mr. Samuel 
Henshaw, there are two generations. Farther north, however, although 
the statement is based upon no exact observation, it is not at all likely 
that there are more than one, and, as stated in the introduction, the 
comparative harmlessness of the species in such regions is probably 
due to the nondevelopment of the second generation. 
Remedies.—There are two classes of remedies as well as an excellent 
preventive that may be used to advantage against this insect. These 
are the collection or destruction of the eggs in the winter, spraying 
the trees against the larvee, and banding unattacked trees to prevent 
the ascent of the caterpillars and the subsequent development of 
moths and the laying of eggs. 
The collection and destruction, or the destruction without collecting, 
of the eggs must be thorough in order to have any practical efficacy. 
The great majority of the hibernating egg masses are deposited low 
down on the trunk of the tree or upon the main limbs, so that they can 

1 Certainly occasionally, and probably always; three, as indicated in the footnote 
on the preceding page. 
21604—Bull, 99-——2 
