


106 
The larva, which feeds on ‘‘Ribbon Wood’’ (Plagian- 
thus betulinus and Gaya Lyallii) is slightly over 4 inch 
in length, rather stout, green, paler underneath, with the 
skin slightly wrinkled; the head is ochreous; there is a 
broad dull crimson dorsal line containing a central black 
bar on each segment; two or three rows of conspicuous 
black warts emitting short’ black bristles, and a very indis- 
tinet greyish lateral line. 
The larva is active in its habits, feeding freely on the 
leaves of its foodplant, during the spring and early 
summer. 
The pupa is enclosed in a slight silken cocoon amongst 
dead leaves. 
The perfect insect appears from November till Feb- 
ruary, and is often very abundant amongst lace-bark trees. 
The large pale-coloured form is extremely common on 
Arthur’s Pass and in the Routeburn Valley, at the head 
of Lake Wakatipu. 
VENUSIA XANTHASPIS. 
(Hermione xanthaspis, Meyr., Trans. N.Z. Inst. xvi., 61. Awlopola 
wanthaspis, Meyr., ib. xviii., 184.) 
(Plate XIII, fig. 5 @.) 
This handsome insect has occurred in the North Island 
on Mount Ruapehu, the Tararua Ranges, near Wellington, 
and in the South Island at Mount Arthur, Lake Guyon, 
Otira and the Routeburn Valley beyond the head of Lake 
Wakatipu. 
The expansion of the wings is from 1 to 14 inches. The fore- 
wings are bright yellow; there is a broad pale reddish-brown 
band on the costa; a conspicuous oval dark brown spot above the 
middle, often touching the costal band, and a triple series of 
minute brown subterminal dots. The hind-wings are pale yellow, 
with a triple series of minute brown dots parallel to the termen. 
The perfect insect appears from December till March. 
It is apparently a rare species, and frequents sub-alpine 
forests, at elevations ranging from about 2,000 to 4,000 
feet above the sea-level. 
Genus 11—ORTHOCLYDON Warr. 
Face smooth slightly rounded. Palpus rather short, very 
shortly rough-scaled beneath. Antennal pectinations of male 
very long, with about 10 apical joints non-pectinate. Thorax 
and abdomen not crested. Fore-wings with apex acute, or even 
subfaleate, scaling smooth, pattern typically consisting of lines; 
areole double, vein 6 well stalked, cell more or less strongly 
inbent in middle, vein 5 arising from slightly before its middle, 
3 considerably proximal to end of cell. Hind-wings continuing 
the colour scheme of fore-wings; cell oblique, vein 5 arising well 
before its middle, vein 3 as in the fore-wings. 
We have three 
Xanthorhoe. 
species, formerly included under 

X.—THE GEOMETRIDAE 
ORTHOCLYDON PRAEFECTATA. 
(Acidalia praefectata, Walk., Cat. xxiii., 781. Acidalia subten- 
‘taria, Walk., Cat. xxvi., 1610. Acidalia absconditaria, 
Walk., ib. 1611; Butl., Cat. N.Z. Lep. pl. iii., 21. Larentia 
praefectata, Meyr., Trans. N.Z. Inst. xvi., 78; Orthoclydon 
pruefectata, Warren, Nov. Zool. i., 393, 1894.) 
(Plate XIV., fig. 21 @, 22 9; Plate II., fig. 16 young larva; fig. 
17 adult ditto.) 
This beautiful insect is generally distributed through- 
out New Zealand wherever flax is abundant. In the North 
Island it is common in the lowland flax areas in the 
Wairarapa and Manawatu districts, but in other 
localities it occurs most plentifully amongst flax growing 
at elevations between 2,000 and 3,000 feet. In the South 
Island it seems to be principally confined to the higher 
elevations, being comparatively rarely met with in the low- 
lands. 
The expansion of the wings is from 14 to 13 inches. In the 
male all the wings are very pale greyish-white tinged with 
brownish and very glossy; there is a number of extremely faint 
wavy grey transverse lines on the outer half of both wings, the 
lines on the fore-wings converging towards the apex; a blackish 
discal dot and sometimes, an oblique row of brownish dots on 
the veins. The female has all the wings snow-white with very 
pale grey markings simiiar to those in the male. 
The egg is about one-thirty-second of an inch in length, slightly 
oval, concave above, covered with numerous hexagonal depres- 
sions; pale yellow with an elongate dappled patch of pale red. 
The young larva (Plate II., fig. 16), when first excluded from 
the egg, is about one-twelfth of an inch in length, rather stout with 
the head very large and flat, pale ochreous; the eyes are black 
and the trophi brown; the body is pale greenish-white with 
numerous black warts surmounted with long black bristles; the 
skin is much wrinkled and there is a yellowish-brown lateral 
line. Before the last moult the larva is about # inch in length, 
moderately stout, of even thickness with its surface very smooth 
and glossy; the head is orange-brown with two red stripes; the 
back yellowish and undersurface and sides pale dull green; there 
is a very broad dull red dorsal stripe; two fine dark red sub-dorsal 
lines; a fine yellowish brown lateral line, and the legs and pro- 
legs are yellowish-brown. It feeds on the underside of the flax 
leaves, excavating long channels in the green substance of the leaf 
about as broad asthe larva. Itis very sluggish and always rests on 
the leaf stretched at fulllength. The full-grown larva (Plate I1., 
fig. 17) isabout linch in length, of even thickness and much flat- 
tened; the head is bright brownish-ochreous with two pinkish- 
brown stripes; the body reddish-ochreous; there is avery broad, 
rich reddish-brown dorsal line; a moderately broad lateral line, 
becoming pinkish towards each extremity; the ventral surface is 
slightly tinged with dull green; there is a row of black tubercles 
on the second, third and fourth segments, and a double row on 
the other segments, except the last; these tubercles emit short 
brownish-black bristles. 
The flattened shape of this larva enables it to secrete 
itself and travel rapidly between the leaf blades of the 
flax (Phornium tenax), near the roots of the plant, and 
the absence or rarity of this insect in lowland flax swamps, 
which are flooded in winter, may, I think, be fairly attri- 
buted to the cireumstanee that the larvae would be 
drowned whilst hybernating at the bases of the leaves. 
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