New Yoek Agkicultueal Experiment Station. 391 



shield, anal plate and legs dark; body pale, but under magnification 

 and with transmitted light it is dirty yellow in color and tuberculose; 

 spiracles brownish, and those commencing with the fourth abdominal 

 segment have above them a pigmented spot, bearing a spine; hairs 

 on dorsum of thorax and abdomen fine and few in number. This 

 description is based on caterpillars in the hibernating stage as taken 

 from the egg mass. 



Mature larva. — The general characters of the larva are as follows : 

 Head, thoracic shield and anal plate, black; anterior and posterior 

 extremities much more narrow than remainder of body; head con- 

 spicuously notched behind; body pale, light yellow, dirty grey or 

 greenish, sometimes appearing brownish on dorsum; four dark 

 setigerous tubercles on dorsum of segments IV to XI inclusive; 

 sides of segments with two rows of similar tubercles more widely 

 separated; segments II to XI with two large dark, kidney-shaped 

 pigmented areas subdorsally; average length 15 mm. Plate XL. 



The following is a detailed description of the full-grown larva, or 

 last instar: Length, 15 mm. average; greatest width 2 mm.; body 

 cylindrical, attenuated at both extremities, especially on posterior 

 part. The segments are outlined by constrictions, and are more 

 or less distinctly divided into three annulets. Pile is very fine 

 and visible only when magnified, otherwise the body appears naked 

 except for a few fine, slender setsG that project from minute, 

 almost obscure, tul^ercles; feet black and equal; prolegs rather short, 

 with a semi-circular brown band on outer face of each foot; crochets 

 three rows deep in a circle; anal plate black and of small size; anal- 

 leg plate brown on dorsal and median portion and black on ventral 

 side. Spiracles are small, slightly elliptical, that of segment XII 

 being the largest. 



Head black, smooth, inclined to oblate in shape, conspicuously 

 incised on posterior margin, sparsely covered with light-colored 

 hairs; antennae small; antennse, epistoma and labrum brown; tips 

 of mandibles dark or blackish brown; clypeus of medium height, 

 acutely triangular, its lateral margins sinuate, and near its base 

 four setae arranged in an inverted arch; paraclypeal pieces long, 

 narrowing toward bases, with two spines one above the other near 

 apex of clypeus; ocelli six in number, with or without pigmentation, 

 the group being protected by setae. 



Cervical shield black, divided on median or deeply incised on 

 posterior margin, with six fine, dark setae arranged in rows of three 

 on each lateral one-half of shield, — one row parallel to anterior 

 margin and one row parallel to posterior margin; laterad of the 

 shield, cephalad of spiracle, a small black pigmented area with three 

 setae of which the central one is longest; directly laterad two setae 

 from a small black pigmented area; spiracle oval and brownish. 



