Watt. — Leaf-mining Insects of yew Zealand. 



465 



transverse line of white near apex ; a small white apical spot ; a broad 

 outwardly-oblique line of white on dorsum at ^, and a small white spot 

 at I ; cilia grey-black. Hindwings dark grey ; ciha grey-black. 



Distribution. 



This appears to be a rather rare moth. It was found first at Aberfeldy, 

 in the Wanganui district, in 1917. The larvae are to be found in December, 

 the pupae in January, and the imagos emerge in February. Old mines 

 were found in Dunedin in May and July. 



Food-jplant. 



Found mining in the long tough leaves of the young lancewood, Pseud-o- 

 panax crassifolium (horoeka), but more commonly in the young succulent 

 leaves of the mature tree. 



Egg-lmjing. 



The egg is laid singly on the upper surface of the leaf, generally close 

 to the midrib. 



The Mine. 



The mine throughout is a simple gallery, more or less straight in its 

 direction. It is made entirely in the upper surface of the leaf, and there 

 is no trace of it to be seen below. The mine starts in a more or less 

 oblique direction till it reaches the midrib or margin of the leaf ; this it 

 follows till it reaches the end of the leaf, and it then either turns back 

 alongside its former track or continues back along the barrier on the other 

 half of the leaf. It never crosses the midrib except in its upper part. 

 On the margin of the leaf the mine closely follows all the irregulari- 

 ties of outline, and extends into the bases of the serrations of the leaf. 

 Portions of the earlier mine may be enveloped by the later broader 



Fig. 30.— Mine of P. panacivagans in the lancewood -leaf. (Tvi^o-thirds natural size.) 



gallery. The average length may be about 10 in. ; commencing with a 

 width of 0'5 mm., the terminal part of the gallery measures about 4 mm. 

 across. Colour light green in fresh mines. There is no tendency to branch. 

 Margins of the mine fairly regular and white. Mines are not very con- 

 spicuous at a short distance. Frass is almost fluid in nature, and occupies 

 a fairly broad brown band in the centre of the early gallery, but in the 

 wider part is dark green or black, and often forms an unbroken line on one 

 side of the gallery ; it is sometimes deposited in short curved transverse 

 lines with the concavity directed forwards. It appears to be deposited 

 chiefly on the upper cuticle of the leaf. 



The Larva. 



Flattened, moniliform ; colour yellowish with broad green dorsal stripe. 

 About 6 mm. in length. A detailed description is kept for a future paper 

 on the Parectopa larvae. 



