26 NEW YORK STATE MUSEUM 



a few conspicuous yellowish setae, the antennae short, yellowish 

 at the base, the basal segment yellowish, the second segment pro- 

 longed, reddish yellow, narrowly yellowish at the extremities and 

 with a few coarse setae apically; mandibles reddish brown, fuscous 

 apically, irregularly bidentate; labial palpi three jointed, mostly 

 pale yellowish, spinneret pale yellowish. True legs a variable yel- 

 lowish and reddish brown, the distal segments somewhat darker, 

 the first pair of prolegs dark brown basally, yellowish brown 

 apically, the anal prolegs . mostly yellowish brown, venter nearly 

 the same color as the dorsum, except that portion between the 

 prolegs, which is a variable yellowish green and yellowish brown. 



Pupa. The pupae are found among the leaves, being sheltered 

 by a very light, thin, yellowish brown cocoon. The pupa is about 

 I inch long, the general color being a yellowish brown, irregularly 

 spotted with dull black. Antennae, leg and wing sheaths closely 

 fused and extending to the tip of the fourth abdominal segment, 

 the terminal segment pale yellowish or yellowish straw ; cremaster 

 composed of an irregular group of four stout, dark brown, re- 

 curved hooks, two distal, two subapical and then two pair of more- 

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



The adult [pi. i, fig. i] is a rather slender bodied, usually snow- 

 white insect having a wing spread of about i finches, the female 

 being a little larger. This moth, according to Professor Packard, 

 may be at once known by its snow-white body and wings, the 

 angulated forewings and notched hind wings. 



Life history. The eggs of this species are deposited usually 

 on the underside of the branches and remain unhatched till the 

 following spring. The young measuring worms appear with the 

 unfolding foliage and, when abundant, trees may be defoliated 

 within two weeks. The caterpillars attain full growth in five or 

 six weeks. The investigations of the outbreak in Ulster county 

 were made July 26, at which time mosj; of the caterpillars were 

 full grown and some had even entered the pupal stage. The final 

 transformations are usually undergone within a shelter of leaves 

 drawn and fastened together with silken strands. Adults were 

 bred from the specimens taken in the Catskills July 31 and August 

 I. The eggs are deposited shortly thereafter, and in the North 

 at least, remain unhatched till the following spring. Professor 

 Comstock states that many eggs in the Georgia outbreak were 

 deposited on leaves, and this led him to conclude that in the South 

 there was probably more than one generation annually. 



