THE CANADIAN ENTOMOLOGIST. 147 



the head is neaily transparent, any colour which it nfiay appear to have 

 being due to the internal organs behind it. 



Larva at Birth. — Pale yelljvv, with four series of long, recurved 

 colourless hairs, two laterodorsal and two substigmatal ; a series of short, 

 straight, dusky, backward-directed bristles accompanying the laterodorsal 

 series. Spiracles brownish. Head dusky-yellow above, labrum and 

 mandibles rich brown, ocellar fields black. Length, 1.24 mm. Breadth 

 head, .19 mm. 



During the first instar the general appearance of the caterpillar alters 

 but little. Being usually distended with food, the body appears to be 

 nearly cylindrical, the segments smooth and rounded except for the sub- 

 stigmatal fold. As the first moult approaches the colour becomes tinged 

 with green. 



Second Stage. — Body onisciform, at first greenish-yellow, with a dusky 

 dorsal stripe from the second thoracic to the eighth abdominal segment 

 (in reality the dorsal blood vessel showing through the transparent skin) 

 threaded by a light mediodorsal line extending to the seventh abdominal 

 segment ; a lighter cloud on the top of the laterodorsal ridge and a similar 

 though less pronounced one on the side of the substigmatal fold, on each 

 segment excepting the first thoracic and last two abdominal. Covered 

 with short red-brown pile. Thoracic shield and spiracles brownish, the 

 posterior edge of the former darker. Head (.54 mm. broad — from exuviae) 

 much as before. 



During this stage the body becomes gradually greener until it is about 

 the colour of young lettuce — a rather bright yellow-green quite unlike the 

 watery pea-green of iriis larvae. The lighter parts of the laterodorsal ridge 

 and the substigmatal fold do not stand out sharply, but blend with the 

 ground colour, and form vague longitudinal stripes. Similarly coloured 

 spots appear faintly on the sides just above the spiracle line. 



Ultimate Stage. — Not differing from preceding stage at first. Later 

 the colour deepens and becomes a vivid, intense green, with the following 

 markings of a green-yellow : the slender mediodorsal line, broader latero- 

 dorsal and substigmatal lines — interrupted by the incisures — much as 

 before. In addition, a series of short oblique lateral dashes, one to a 

 segment except the first thoracic and last abdominal, fainter and usually 

 much reduced on the second and third thoracic and on the seventh, eighth 

 and ninth abdominal segments, elsewhere meeting the laterodorsal marks 

 anteriorly, thus forming acute angles directed forwards ; a faint cloud 



