10(5 CANKER-WORM. 



ber of eggs laid by each individual varies accordingly. I have found 

 in the smallest moths only fifteen or tvs^enty eggs, whilst the largest 

 contain from one hundred and forty to one hundred and fifty. 



As the season for laying the eggs is now past, I have made a num- 

 ber of examinations with the view of determining definitely where 

 the eggs are deposited. Whilst the moth of the Tent-caterpillar 

 covers her eggs with a water proof varnish and deposits them on the 

 exposed twigs, the Canker worm moth does not so protect her eggs, 

 and only secretes enough of a glutinous fluid to stick the eggs to 

 the bark. She therefore always seeks some other protection, and 

 this is furnished almost exclusively by the loose scales of bark. In ac- 

 cordance with this statement no eggs are found on the twigs or the 

 small smooth branches. Dr. Harris states that the eggs are deposited 

 *' in the forks of the small branches, or close to the young twigs and 

 buds." But I must conclude that Dr. Harris did not make this state- 

 ment from his own observation. I have recorded above that in cold or 

 stormy weather the female moth, after she has ascended the tree, and 

 passed out upon the branches, often seeks the slight and only available 

 shelter aflforded by the forks of the twigs, and it was natural to expect 

 that she would deposit her eggs there. But if she ever so deposits 

 them, it must be very rarely and exception ably. After a diligent 

 search with the aid of a lens on several different occasions, upon 

 heavily infested trees, I have never succeeded in finding any of the 

 eggs in this situation, nor elsewhere than under the scales of bark, with 

 the solitary exception, above referred to, of the protection afforded by 

 the crumpled leaves and cones of the Phycita nehulo.^ 



A corroboration of this view is furnished by a remark of my corres- 

 pondent, Mr. J. Tinker of Wisconsin, who, speaking of these insects, 

 which have been very destructive upon his place, incidentally remarks, 

 " They do not bother small, smooth barked trees, either in the nursery 

 or orchard." I may here add that, in a subsequent letter, Mr. Tinker 

 stated that he had found the eggs of this insect in the dried apples 

 which had adhered to the tree through the winter. 



* An interesting instance of this habit of the Caaker-worm moth was communicated to me 

 by Mr. Elmer Baldwin. He stated that at one time his orchard became infested by these in- 

 sects, and that at the same time the Leaf-crumplers were very numerous and troublesome, and 

 that the moths availed themselves of the shelter thus afforded for the deposition of their eggs, 

 to such an extent, that he regarded it as one of his most efiScient modes of getting rid of the 

 Canker-worms, to gather and destroy the crumpled nests of the Pluycitce — thus destroying two 

 noxious insects by the same operation. 



