Juno, tlie 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 larva? 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 Iarva3 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 1st 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 larva? 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 Iarva3 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. 1 In New- York and Brooklyn there ^ire two 

 well-marked generations. At Boston, as is learned from Mr. Samuel 

 Heushaw, 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 Iarva3, 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 



Certainly occasionally, and probably always, three, as indicated in the footnote 

 on the preceding page. 



21604 Bull. 99 2 



