64 NEW YORK STATE MUSEUM 



as the dorsum, except that part between the prolegs which is variable 

 yellowish green and yellowish brown. 



The pupae occur among the leaves, being sheltered in very light, 

 thin, yellowish brown cocoons. The pupa is about one inch long, 

 the general color being a yellowish brown irregularly spotted with 

 black. The antennae, legs and wing sheaths are closely fused and 

 extend to the tip of the fourth abdominal segment; the terminal 

 segment is pale yellowish or yellowish straw; the cremaster is com- 

 posed of an irregular group of four stout, dark brown, recurved 

 hooks, two distal, two subapical and then two pair of more slender 

 ones, the more distal being lateral and the others dorsal. 



Control measures. This species, as stated before, is not an 

 important shade tree pest, since the English sparrow can usually be 

 relied upon to keep it within bounds. The control of this insect 

 in woodlands is a much more serious problem and must depend in 

 large measure upon natural enemies, such as parasites and especially 

 our native insectivorous birds. These latter should be protected in 

 every feasible manner. 



Birch leaf skeletonizer (Bucculatrix canaden- 

 sis ell a Chamb.). This small leaf feeder was generally 

 abundant, though not exceptionally numerous, upon the white 

 birches at Kinderhook. This occurrence is probably the western 

 border of a severe outbreak in New England, recently recorded by 

 William R. Thompson^ and comprising areas in Connecticut, Massa- 

 chusetts, New Hampshire and Maine, at least. Nine years ago this 

 species was exceedingly numerous in the vicinity of Albany, skele- 

 tonizing practically all of the foliage of our ordinary white or gray 

 birch, Betula poplulifolia. The full-grown caterpillar is 

 only about one-fourth of an inch long, light green or yellowish green 

 and most easily recognized in association with the peculiar, oval or 

 circular, whitish, moulting cocoons about one-twelfth of an inch in 

 diameter. The larvae may be found upon the trees in August or early 

 September, feeding upon the soft parenchyma of the leaf and, when 

 numerous, skeletonizing the foliage. The winter is passed in a nar- 

 row, brownish yellow, ribbed cocoon about one-fifth of an inch long. 

 The parent moth is a delicate, bright brown insect with a wing 

 expanse of three-eighths of an inch. The wings have two subtri- 

 angular blotches on the inner margin which, when these organs are 

 closed, -form two white dorsal saddles, while, in addition, there are 

 three silvery white bars which run from the outer edge about half 



1 1910 Journ. Econ. Ent. 3 :436. 



