Watt. — Contributions to Entomology of New Zealand. 409 



seldom falls short of 7 in. or 8 in. The deposition of tlie frass in the mine 

 is an important point for identification. In this case it at first occupies 

 the central portion of the mine, forming a narrow slightly waved line of 

 more or less detached granules, leaving a pale space on either side of it. 

 In some cases this line of frass is continuous without indication of a granular 

 consistency, and looks as if it had been deposited in a soft condition and 

 had run together into a homogeneous thread ; at times it is vermiform 

 in character, according to the manner in which the larva was feeding 

 while advancing. This arrangement is suddenly stopped by a break or 

 clear space in the mine, after which the frass granules become more prolific. 

 This continues for some distance, when there is another change— the mine 

 goes deeper into the leaf and becomes choked throughout its whole length 

 with the frass granules. These changes in the character of the frass denote 

 the larval moults. At first the mine is white and in marked contrast to 

 the rest of the leaf, but as moisture gets imder the cuticle it becomes much 

 less conspicuous ; however, the leaf soon becomes brown along the track 

 of the mine, and so it becomes even more conspicuous than before. The 

 latter portion of the mine is first dark green, but as the frass dries and 

 the cuticle of the leaf withers it becomes dark brown. 



The Larva. 



1st Stadium. — The prothorax is greatly enlarged ; the remaining seg- 

 ments are well rounded, and rapidly diminish in size towards the anus, 

 giving the grub a very attenuated appearance. Colour light green, head 

 light brown. There appear to be none of the primary setae present ; to 

 discover these a ^ in. objective was used without effect. The head is 

 triangular equilateral, flattened, somewhat retractile. 



2nd Stadium. — Head large ; the cheeks are margined ^dth black ; the 

 clypeus has also the black margin, is broad against the labrum, and slightly 

 widens till about two-thirds of its length, when it narrows considerably 

 till it meets the angle formed by the cheeks on the top of the head ; 

 mandibles prominent ; the cheeks are pale green, with a darker area 

 extending their whole length against the clypeus ; labrum dark brown. 

 Prothorax very large, meso- and meta-thorax smaller than the prothorax, 

 the latter smaUer than the former, all three flattened dorsally and ventrally. 

 Abdominal segments well rounded, of almost equal size, slightly diminishing 

 towards the anal end, somewhat flattened dorsally and ventrally. Colour 

 light green, darker in centre. Primary setae still absent. 



3rd Stadium. — Colour greenish-yellow, a faint white spiracular line. 

 Length just before emerging from leaf (fully extended), about 6-20 mm. ; 

 breadth, about 0-90 mm. Body covered with a fine pile. Spiracles 

 circular, minute, very inconspicuous. Prolegs on abdominal segments 3, 4, 

 and 5 ; armed with single row of 7 brown, well- formed hooks. Primary 

 tubercles bearing short, simple, and in most cases single transparent setae. 

 Tubercle i is minute, above ii in the thoracic segments, but some way 

 in front of and below ii in the abdominal segments. • ii is well de- 

 veloped, iii is coalesced with two setae on the prothorax, where it is 

 prespiracular ; in the meso- and meta-thorax is beneath but in front of i, 

 and has a minute secondary seta above and in front of it, is post-spiracular 

 in the abdominal segments, iv in the prothorax is prespiracular, and is 

 coalesced with a second seta (probably v), is beneath and in front of iii in 

 meso- and meta-thorax, is post-spiracular and behind iii, almost directly 

 beneath ii, in the abdominal segments, v is absent in the meso-, meta- 

 thorax. and abdominal segments, vi appears to be present in the prothorax 



