■^^.jirp. — Contributions to Entomology of New Zealand. 407 



Art. XL. — Contributions to the Entomology of Neiv Zealand : No. 8^ 

 Parectopa citharoda Meyr. {Order Lepidoptera). 



By Morris N. Watt, F.E.S. 

 [Read before the Wanganui Philosophical Society, 1st November, 1915.] 



Parectopa citharoda Meyr. 

 ParectojM citharoda Meyr., Trans. N.Z. Inst., vol. 48, p. 418. 



^, Ovum. 



Class.— Flat. 



Shape. — Oval, wafer-like ; base flat ; upper portion rounded. The 

 shell appears to extend beyond tlie egg proper, forming a wide flat trans- 

 parent rim. 



Dimensions. — Total width, 0-40 -0-50 mm. ; width, excluding rim, 

 0-28 - 0-35 mm ; total length, 0-59 -0-75 mm. ; length, excluding rim, 

 0-41 - 0-47 mm. ; height, about 0-10 mm. 



Sculpture. — Devoid of sculpturing, except for very minute white spots 

 (elevations) scattered over the surface of the shell in regular hexagonal 

 formation. 



Micropyle. — Not distinguished. 



Shell. — Transparent, thin and flexible, but fairly strong ; shiny, almost 

 glossy ; covered with minute wrinkles. 



Colour. — White ; the growth of the embryo can be clearly followed. 



Note. — The ovae are well cemented to the leaf-surface ; are large for the 

 size of the moth. Period of incubation, about fourteen days. (Described 

 14th February, 1915.) 



Egg-laying. 



The eggs are laid indiscriminately on either side of the leaf of the food 

 plant ; this follows from the fact that the leaves naturally grow in a vertical 

 position, and there is little, if any, difference between the two surfaces. 

 The eggs are also laid with practically no fixed position between the margin 

 of the leaf and the midrib. There is a distinction, however, in that thev 

 are laid invariably on young tender leaves, towards the upper (as opposed 

 to the basal) end. The young seed-pods are also favoured by the parent 

 moth for the deposition of her ovae. 



Mine. 



The mine is not difficult to detect, being most conspicuous. It has 

 no definitely fixed position, but often follows the midrib or the margin 

 of the leaf for some distance. It is to be found on either side of the leaf, 

 for the same reason as the deposition of .the ovum ; for the same reason, 

 also, the larva, when full grown, leaves the leaf from whichever side is 

 most convenient to it. The gallery is long and narrow, in many cases 

 first starting from the site of the egg in a small semicircle and then con- 

 tinues more or less straight till some obstruction is reached, as, for instance, 

 the hard midrib or the margin of the leaf. The obstruction may be 

 followed for some distance, and in this way the mine may become much 

 twisted and contorted. As the larva grows, the mine naturally becomes 

 gradually wider till the last three or four days of the larval existence in 

 the leaf ; during this latter period the gallery is much widened, and be- 

 comes a large irregular blotch or chamber. The total length of a mine 



