454 



Transactions. 



direction for one almost at right angles to the earlier one, now crossing 

 the leaf in curved sweeps from edge to midrib, this latter forming a certain 

 obstacle to trespass on the other half of the leaf. The spot where the 

 general change of direction takes place no doubt marks the situation where 

 the larva underwent its first moult. On reaching the upper region of the 

 leaf the mine becomes less vermiform in character and becomes rather tor- 

 tuous in its direction, crossing the midrib in its upper and thinner part, and 

 continuing down the other half of the leaf in more or less close proximity to 

 the midrib or outer margin. This latter portion of the mine is often deeper 

 in the leaf than the earlier vermiform part, and consequently is more difficult 

 to detect. In this final part the width of the gallery is about /^ in. The 

 entire mine is in the upper surface of the leaf, and no trace of it can be seen 

 beneath. Colour of mine a paler green than other portions of the leaf, 

 but even so the mine is not a very conspicuous object ^t a little distance. 

 The terminal portion of the gallery may be slightly enlarged, and within 

 it the cocoon is constructed, a small area of the upper cuticle of the leaf 

 at the extreme end of the mine being first prepared to a transparent 

 thinness for the exit of the pupa later. The frass is finely granular, pale 

 in colour, not very abundant, and occupies a rather broad band in the 

 central third of the gallery. 



The South Island type differs from the above. In the earlier part the 

 mine is a simple vermiform gallery very similar to that of P. -panax- 

 vermiformella both in size and character ; later, however, instead of 

 ending in a somewhat tortuous and widened gallery, it expands into a 



Figs. 14, 15. — INIines of P. panacivermiforma (South Island) in leaves of 

 Nothopanax simplex. (Natural size.) 



relatively large blotch, which^may occupy the entire leaf in small ones, 

 or all or the greater part of one half of the leaf in larger ones. The entire 

 mine is on the upper surface of the leaf, and is pale green in coloiu, and 

 not very conspicuous at a distance The final blotch may occupy about 



