180 THE ENTOMOLOGIST. 



The ova were deposited on June 29th, singly, on upper and 

 lower sides of leaves of birch. 



The following day the ova were pale green, opalescent, and 

 •seinitransparent, the veins of the leaf showing through the 

 ovum. The length was "9 mm. by *7 mm. As the larva develops 

 in the ovum it shows conspicuously, especially the dark head. 

 The surface is of the usual tortrix pattern, divided into a 

 number of spaces by ridges, irregularly shaped, but with the 

 sides of the spaces consisting of straight lines ; the polar axis of 

 the ovum is, of course, horizontal. The larvae commenced to 

 emerge on July 13th, and the following observations were made 

 on one that hatched on that date. 



The newly-emerged larva is about 1*25 mm. long, head 

 brown, lobes prominent, it has a black dot in front of each lobe, 

 the jaws are honey brown ; the prothoracic plate is greenish 

 white, the legs and feet black ; the segments behind prothorax 

 and claspers are greenish white ; there is no sign of anal plate. 

 This larva was put between two birch leaves and kept in an air- 

 tight tin box. On July 15th it was eating the lower cuticle of 

 the upper leaf, making small sinkings in it. 



On July 23rd the larva had changed into second instar, and 

 was now 2 mm. long; the head was jet black and glabrous, with 

 the lobes not so prominent as in the last instar ; the prothoracic 

 plate was dark greenish grey with a wide division between it and 

 the head, in colour light grey ; the remaining segments, prolegs 

 and claspers were light greenish grey ; the larva was very trans- 

 parent, the contents of the alimentary canal showing as a 

 reddish-brown line ; the tubercles were rather noticeable, and 

 lighter than the surrounding areas ; the larva was spiny, the 

 anal plate was not noticeable. 



On July 30th the larva had changed into the third instar ; 

 it was then 3"5 mm. long ; head dark brown and glabrous, lobes 

 prominent ; prothoracic plate lighter brown ; division between 

 head and prothorax light grey. The prolegs were tipped with 

 black, otherwise the larva was in all respects as in last instar. 

 In this instar the larva fed on the inner cuticle of both leaves. 



On August 3rd the larva was in the fourth instar, and measured 

 6 mm. in length ; the head was intensely black and glabrous, 

 the lobes were prominent ; the prothoracic plate was light 

 greyish green clouded with darker markings near the rear 

 margin ; included in these was a black blotch on each side in the 

 subdorsal area. The larva tapered very much to anal extremity. 

 It was with the above exceptions similar to the last instar in all 

 respects. 



On August 10th the larva had changed into fifth and last 

 instar and was then 10 mm. long. 



The changed appearance in this instar was very noticeable ; 

 the head was light greyish green without any darker markings, 



