The larva when full grown is about 3¾ inches in length, elongate,
slightly thicker in the middle, and with the skin smooth. It is
ash-colour, speckled with minute points of black and red; two minute
carmine spots are situated close together on its back; and, when in
motion, two large triangular black splashes are also visible. The under
side of the larva is dull white, with several dull olive spots
corresponding to its ventral prolegs. Its head is small, and pale Indian
yellow in colour; its anal and ventral prolegs are large; on being
touched the caterpillar coils itself up very rapidly and closely.
The specimen from which Mr. Colenso's description was taken, was found at
rest on the trunk of a large acacia-tree, which is probably the food-plant
of the larva.
The pupa is enclosed in a cocoon formed of leaves fastened together with
silk. The insect appears to remain in this condition for about two months.
The pupa-case (after emergence) is nearly cylindrical, very obtuse at the
head, and tapering regularly downwards from the end of the wing-cases, with
the tail conical; the abdominal segments are very strongly marked. Its
colour is dark red, with a bluish or violet bloom, but smooth and shining
on its prominent parts.[23]
The perfect insect appears in January, February, and March, but it is
rather a scarce species. It is attracted by light, and thus occasionally
enters houses, where specimens are generally captured. Mr. Meyrick states
that this insect occurs commonly in Eastern Australia.[24]
Genus 4.--RHAPSA.
"Eyes naked. Palpi very long, obliquely ascending, loosely rough-scaled
throughout, second joint with dense long projecting tuft above towards
apex, terminal joint moderate, Antennæ in male moderately bipectinated,
apex simple. Thorax and abdomen not crested. Fore-wings in male beneath
with large broad costal fold on anterior half."--(Meyrick.) (Plate II.,
figs. 16 and 17 neuration of [M] _Rhapsa scotosialis_; fig. 18 head of
ditto.)
We have two species.
RHAPSA SCOTOSIALIS, Walk.
(_Rhapsa scotosialis_, Walk., Suppl. 1150. _Herminia lilacina_, Butl.,
Proc. Zool. Soc. Lond. 1877, pl. xlii. 11. _Rhapsa scotosialis_, Meyr.,
Trans. N. Z. Inst. xix. 38.)
(Plate VI., fig. 5 [M], 6 [F].)
This remarkable species is extremely abundant and generally distributed
throughout the country.
The expansion of the wings is 1-3/8 inches. _The fore-wings have the
costa considerably arched towards the apex, and the termen is bowed
outwards in the middle_; the colour is pale brown in the male and dark
brown in the female; there are several obscure black marks near the base;
_the orbicular is very small, orange or pale grey outlined in black, the
claviform is absent, the reniform is conspicuous, the outer edge is much
indented, the inner edge is outlined with dull orange-red_, there is a
black blotch between the orbicular and the reniform; beyond the reniform
there is a curved transverse line enveloping a series of minute black
dots, then a very conspicuous wavy transverse line shaded towards the
base of the wing; _there is a pale triangular area at the apex_, and a
series of small crescentic dark brown markings on the termen; the cilia
are dark brown. The hind-wings are greyish-ochreous; there is a rather
faint line across the middle, followed by a broad shade; a series of
{37}small crescentic marks is situated on the termen; the cilia are dark
greyish-ochreous. _The antennæ of the male are strongly bipectinated. The
female is considerably darker, the markings are less distinct and
numerous, and there is no black blotch between the orbicular and the
reniform._
Some male specimens are much paler in colour than others, but with this
exception there does not appear to be any important variation.
The eggs are round, flattened above, bright green, becoming dull purplish
about two days after being laid.
The young larva when first emerged is about 1/8 inch in length; the head
is brown; the body dull white, with a series of black tubercles round
each segment, each tubercle emitting a tuft of bristles. The larva has
sixteen legs, but the two anterior pairs of ventral claspers are not
employed in walking, the caterpillar's mode of progression, consequently,
resembling that of a larva with twelve legs only. The food-plant is
_Piper excelsum_.
The perfect insect appears from September till April, and is very common
amongst undergrowth in the forest. It is seldom found in the daytime, but
at night it is extremely abundant in densely wooded situations. It flies in
a very stealthy manner, and may soon be recognised on the wing by this
feature alone. When disturbed it always secretes itself amongst dead fern
fronds or other vegetable refuse, where its sombre colour effectually
conceals it.
The costal fold on the under side of the fore-wing of the male contains a
very large tuft of extremely long hairs. It probably emits a scent
agreeable to the female.
RHAPSA OCTIAS. Meyr.
(_Hyperaucha octias_, Meyr., Trans. Ent. Soc. Lond., 1897, 383.)
(Plate VI., fig. 7.)
This interesting little species has recently occurred in some numbers in
the neighbourhood of Wellington. I have no record at present of its capture
in any other New Zealand locality.
The expansion of the wings is about 1 inch. The fore-wings have the costa
straight, and the termen with a large projection slightly above the
middle; the colour is pale brown; _there is a broad dark brown patch on
the costa at the base_, a jagged transverse line at about one-fourth, _a
very broad, oblique, blackish-brown, oblong patch on the costa at about
one-third; beyond this patch is situated the reniform which is very
large, indented towards the termen where it is outlined in dark brown_;
there is a very fine jagged transverse line from beneath the reniform to
the dorsum; _a large irregular patch of dark brownish-black just before
the apex_, and an obscure transverse line; there is a series of minute,
dark brown, crescentic marks on the termen. The hind-wings are dull
whitish-grey; there is a faint blackish dot in the middle, a wavy line a
little below the middle, and a terminal series of small dark marks. The
antennæ are filiform in both sexes.
The perfect insect appears in October, November and December. It frequents
dense forest ravines, and is generally disturbed from amongst dead leaves
or old fern fronds. It is usually a very scarce species, but appears to be
much commoner in some years than in others. According to Mr. Meyrick, it is
also found in Australia.
This species is placed by Mr. Meyrick in the genus _Rhapsa_. The simple
antennæ and absence of the broad costal fold in the males would appear,
however, to remove it from that genus, as restricted by him in the
'Transactions' of the New Zealand Institute, xix. 38. In all other respects
it appears to conform to the genus.[25]
{38}II.--THE NOTODONTINA.