64 N. S. ENTOMOLOGICAL SOCIETY 



The larvae pass through a series of seven moults, the final 

 one being cast after the cocoon is spun and can readily be seen 

 attached to the caudal extremity. It is characteristic of the 

 larvae in all stages when about to moult, to spin a quantity of 

 silken threads over the surface of the leaves whereon they in- 

 tend to moult, the preparation and process of moulting often 

 lasting from one to one and a half days. After the fourth 

 moult has been cast, the larvae feed only for a short time, then 

 wander about in search of a suitable hiding place, such as under 

 loose bark or dried leaves, there to hibernate during the winter 

 months. With the warm days of spring they reappear and 

 start feeding on the tender unfolding leaves, becoming fully 

 grown usually in the early part of Julv, though there is consid- 

 erable variation in this regard. Some larvae do not reach full 

 size until August and four specimens reared in the laboratory 

 actually hibernated through a second winter. 



Description of Instars. 



First Instar. Five distinct rows of warts can readily be dis- 

 tinguished. The first or dorsal row (1), is situated just laterad 

 of the median dorsal line and immediately dorsad of the second 

 or subdorsal row (II) on the meso — and methathorax and cep- 

 halo-dorsad on the abdominal segments. Laterad of the sub- 

 dorsal row (II) is the supraspiracular row (III), while just be- 

 low this is the subspiracular row (IV), row (V) being situated 

 near the margin between the lateral and ventral surfaces. Row 

 (I) is smaller than the others and remains very minute through- 

 out the succeeding instars, except in the first four and the eighth 

 segments, where it later is merged in the dorsal tufts. On the 

 prothorax, the two warts of row II are situated on the shield, 

 where they are contiguous; those of row III are larger and more 

 prominent than the others and thus foreshadow the develop- 

 ment of the hair pencils which later develop from them. The 

 body is at first greenish, later greyish in color, mottled with 

 darker markings, the hairs clothing the warts, being of a sim- 

 ilar color. Length of newly hatched larva, 2.4 m. m.-2.7 m. m. 

 head, .5 m. m.-.52 m. m. wide. 



Second Instar. Warts clothed with tufts of black and 

 white hairs intermingled, the former predominating. The 

 hairs are of unequal length, those on the thoracic segments 

 being longest. This instar differs from the preceding in the 

 greater development of the hair pencils on the first thoracic 

 and, to a lesser extent, on the last abdominal segment, which 



