Warr.—Leaf-mining Insects of New Zealand. 487 
men 
surface, pushing at first directly backwards and later laterally, in this way 
generally are subjected to a thorough cleansing ; all extraneous matter 
is removed. The egg-laying capacity of any individual probably reaches 
about 200 ova. The time taken in probing a cavity and depositing the 
egg rarely exceeds a minute. During the proceedings the back legs are 
at times violently stamped upon the leaf. Occasionally leaves are found 
crowded with these pockets, but in such cases only a few of them will 
contain eggs. 
Under normal conditions lava hatches on sixth day after laying of egg, 
and commences burrowing against upper cuticle of leaf. It passes through 
three stadia: the first occupies about three days, moult taking place about 
1 cm. along mine; second stadium occupies about three days, moult occur- 
ring about 4 ст. along mine; third and final stadium occupies about four 
days, and lava pupates within mine. кышы 
Full-grown lava a minute cylindrical grub; cephalic extremity slightly 
broader than caudal end; colour white, inclining to pale green on account 
of assimilated food and transparency of skin; head is largely retractile ; 
posterior respiratory processes minute and black, anterior pair white and 
longer. Average length of full-grown larva, 3mm.; average diameter, 
'9 mm 
The Mine. (Plate 39, fig. 1.) 
Mine a long narrow gallery, frequently forming an intricate pattern on 
leaf owing to tortuous course, it and other mines on same leaf crossing each 
Other in grand confusion. Longer or shorter blind branches are frequent. 
Margins of gallery even and almost parallel. The greater length of mine, 
às a rule, lies close against upper cuticle, and there is little trace of it on 
under-surface. In cases where egg has been laid on under-surface the mine 
will lie close against this for a short distance at first, but sooner or later 
