Genus 1.--ARGYROPHENGA.
Eyes glabrous. Club of antennæ somewhat abrupt. Fore-wings with lower
margin of cell greatly dilated towards base; veins 8, 9, 10, and 11 out
of 7; vein 12 greatly dilated towards base.
Of this genus there is one species in New Zealand.
ARGYROPHENGA ANTIPODUM, Doubleday.
(_Argyrophenga antipodum_, Doubleday, Ann. and Mag. Nat. Hist. xvi. p.
307 (1845); Gen. Diurn. Lepid. pl. 63, fig. 6 (1851); Butler, Erebus and
Terror Lep., pl. 8, figs. 4, 7 (1874).)
(Plate XI., fig. 4 [M], 5 [F], 3 variety, 6 under side of [M], 7 under side
of variety; Plate III., fig. 4 larva, fig. 29 pupa.)
This species occurs commonly on the tussock lands from Christchurch to
Invercargill. In the provinces of Nelson and Marlborough it is, I believe,
confined to situations having elevations of from 2,000 to 4,000 feet above
the sea-level. It has never been captured in the North Island.
The expansion of the wings varies from 1-3/8 to 1¾ inches. _Above, all
the wings are dull brownish-black, paler near the body; the outer portion
of each is covered with a large patch of bright orange-brown (northern
form), or fawn colour (southern form); on the fore-wings this patch
contains a large oval black spot, with two white dots in the middle; on
the hind-wings there are two, three, or four black spots, with one white
dot in the centre of each_; beneath, the markings on the fore-wings
resemble those of the upper surface, except that there are often several
short silvery stripes near the apex; the hind-wings are dull yellow, with
silver streaks between the veins, and one broader streak in the centre of
the wing. The female is much paler than the male, with the borders of the
wings whitish.
This insect is extremely variable. The colouring appears to be much
influenced by local conditions. On the Dun Mountain, Nelson district, at an
elevation of about 2,700 feet, a very small light form occurs in which the
sexes are almost exactly alike. There are only two perfect spots on the
upper surface of the hind-wings; the other spot is {111}rudimentary, and
has no white central dot. On the under side there are no silver stripes
near the apex of the fore-wings, and only five or six silver stripes on the
marginal portions of the hind-wings (see Plate XI., figs. 3 and 7). At
Kekerangu, on the "Chalk Range," at an elevation of from 3,000 to 4,000
feet, a similar but slightly larger form occurs. On the Tableland of Mount
Arthur, Nelson district, 3,600 to 4,600 feet above the sea-level, the
females are paler than in either of the preceding forms, and the males
darker, so that the sexes are well marked; but there are no silvery stripes
on the under side of the apex of the fore-wings, and usually only five
stripes on the marginal portions of the hind-wings. Finally, in the
Canterbury, Otago and Southland butterflies (southern form), we have the
large, very dark reddish-brown coloured male insect with large ocelli, and
the extremely pale yellow female with small ocelli, the two sexes here
exhibiting the greatest differentiation. On the under side, the male has
several small silver stripes near the apex of the fore-wings, and seven
stripes on the marginal portions of the hind-wings. (See Plate XI., figs.
4, 5, and 6.) In elevated situations in Canterbury, however, I have taken a
somewhat similar variety to that found on the Mount Arthur Tableland. I
have also taken similar forms on Mount Robert near Lake Rotoiti, Nelson
district, these having, in addition, numerous white hairs on the wings near
the body.
Besides these extreme variations, which appear to be largely dependent on
local conditions, great variability exists with respect to the number and
size of the ocelli or white-centred spots. In some specimens there are no
ocelli on the hind-wings; in others, two, three, or four very minute ones,
whilst others have all four very large. Occasionally specimens have a
minute ocellus below the large one on the fore-wings. Were it not for the
intermediate varieties, there would probably be little hesitation in
separating the extreme forms of this insect into several distinct species;
but as they are connected by a host of intermediate forms, it is quite
impossible even to divide them into varieties.
In a paper communicated to the 'Entomologist' in February, 1889,[52] by Mr.
W. W. Smith, the author makes some interesting remarks on the variation of
this butterfly, as observed by him in Canterbury and Otago. After pointing
out the great diversity exhibited by different specimens in the depth of
colouring, and in the number and size of the ocelli, he states that in his
opinion the greatest variation occurs during the summers that succeed wet
winters. In the year 1888 I had the opportunity of inspecting a most
interesting series of this insect, presented by Mr. Smith to the Wellington
Museum. They embraced specimens of very varied colouring, and included,
amongst other remarkable forms, a male, which was entirely destitute of all
ocelli, both on the fore- and on the hind-wings. Amongst these specimens,
however, I did not see any resembling those I have described from Nelson
and Marlborough. This collection has, I regret to say, since been disposed
of by the Museum authorities, and cannot therefore be utilised by New
Zealand students.
The larva of this insect feeds on the tussock grass (_Poa australis_). Its
length, when full grown, is about 1 inch. The top of the head is furnished
with a very large process, which projects forwards. The body is much
attenuated towards the tail, which is bifid. The general colour is dull
green, with a crimson line on each side and numerous alternate lines of
yellow and white. The legs and prolegs are very small. There are four
wrinkles on the posterior edges of each segment.
{112}When feeding, this caterpillar rests on a blade of the tussock, where
it is very inconspicuous. It appears to prefer the dead or drier portions
of the grass, and feeds and grows very slowly. It is strictly diurnal in
its habits, relapsing into a death-like repose at night.
The pupa is suspended by the tail to an upright blade of the tussock. In
the specimen I reared, I was fortunate enough to witness the actual
transformation, and during the process, observed it seizing hold of the
larval skin with its posterior segments, its manoeuvres whilst thus engaged
exactly resembling those of the pupa of _Anosia erippus_, described above
by Professor Riley.
The length of the pupa is about ½ inch. Its colour is bright green, with a
reddish line along the edge of each wing-case, and several white lines on
the sides and back.
The perfect insect appears from December till the end of March. It is
usually very abundant where found, the males being more numerous than the
females in the proportion of about five to one. It flies amongst the
tussock grass in a weak and aimless manner. When rapidly pursued it has a
habit of plunging into a tussock and closing its wings, where it remains
quite invisible until the danger is past.
The silver stripes on the under side of the hind-wings are very protective
to the insect when at rest on its food-plant, the striped coloration of the
larva and pupa no doubt serving similar protective purposes.
Genus 2.--DODONIDIA, Butl.
Characters as in _Argyrophenga_, except that vein 11 of the fore-wings
rises from upper margin of cell, shortly before transverse vein.
We have one species in New Zealand.
DODONIDIA HELMSI, Fereday.
(_Dodonidia helmsi_, Fereday, Trans. N. Z. Inst. xv. 193.)
(Plate XI., fig. 14, fig. 15 under side; Plate III., fig. 5 larva, fig. 28
pupa.)
A single specimen of this interesting butterfly was discovered by Mr. R.
Helms, in 1881, on the Paparoa Range, near Greymouth, at an elevation of
about 1,500 feet above the sea-level. Until within the last three years
only three other specimens had been captured, viz., one near Wainui-o-mata,
in Mr. A. P. Buller's collection; one on the Dun Mountain, Nelson, at an
elevation of about 2,500 feet, which is in my collection; and one on the
Tableland of Mount Arthur, at about 3,300 feet, which was kindly given to
me by Mr. C. W. Palmer. In the summer of 1894-95 several specimens were
captured by Mr. P. Marshall near Wanganui,[53] and during the same season
Messrs. Smithers and Hawthorne discovered the insect in considerable
abundance at a locality near Silverstream, in the Wellington district.
During the two following summers additional specimens were obtained near
Silverstream, and I was fortunate enough to discover there a number of
specimens of the larva, which furnished the material for the illustration
and description of the preparatory stages of the insect given in this work.
The expansion of the wings is about 2 inches. _On the upper side all the
wings are dark brown. The fore-wings have two broad bands of
yellowish-orange, the outer one containing a {113}small patch of dark
brown near the costa, which touches a white-centred black ocellus. The
hind-wings have one large patch of yellowish-orange containing two
ocelli; a large ocellus, surrounded by a broad ring of reddish-orange, is
situated on the tornus_; the tornus is produced into two very broad but
short tails, which are bordered with white cilia. On the under side the
fore-wings are light ochreous-yellow; there is a shaded brown patch at
the base; the termen is broadly bordered with brown, the border
containing a silver streak; two broad brown patches are situated on the
costa, the outer one terminated by a small ocellus, and enclosing a
silvery patch near the apex of the wing. _The hind-wings are silvery,
narrowly bordered with deep reddish-brown, with five deep reddish-brown
stripes running from the costa towards the tornus_; the fourth stripe
from the base of the wing contains three ocelli surrounded by yellow
rings; a conspicuous ocellus is situated at the tornus, surrounded by a
broad orange-red ring.
This insect appears to vary a little in the extent of the yellowish-orange
colouring of the upper side. It also varies in size, specimens from the
North Island being slightly larger than those from the South Island.
The larva feeds on a species of sedge (_Galinia setifolia_), which always
grows abundantly in the birch forests, where the butterflies are found.
When full grown the length of this caterpillar is about 1¼ inches. Its body
is much attenuated at each end and rather stout in the middle; the head and
tail are bifid; there are numerous straight, shallow, transverse wrinkles
on each segment, especially towards the head. The colour is green, with a
number of fine, paler and darker green, dorsal and lateral lines; the head
and thirteenth segment are yellowish. The legs are very minute, and the
prolegs of moderate size. It is extremely susceptible to the attacks of a
Dipterous parasite. In fact, out of thirty larvæ kept by Mr. Hawthorne and
myself, no less than 75 per cent. were thus destroyed. This larva feeds on
the leaves of the sedge, eating out long notches parallel to the veins of
the leaf. These notches are the best guides to follow in searching for the
larva, as the colouring of the caterpillar renders its discovery amongst
the food-plant extremely difficult. The larvæ should be looked for during
the end of December or the beginning of January.
The pupa is rather stout, light green, with the edge of the wing-case and
the prominences formed by the back and palpi, edged with crimson and white.
It is suspended by the tail to any firm object in the neighbourhood of the
sedge.
The perfect insect appears in February. It frequents sunny glades in the
birch forest, usually at considerable elevations above the sea-level. Mr.
Helms informs me that he has seen specimens near Greymouth in October, and
hence concludes that there are two broods in the year. The butterfly is
very difficult to capture, as it has a most provoking habit of resting on
the foliage of the birch-trees, just out of the collector's reach. I am
unable to explain the object of the remarkable colouring of the under side
of this insect, but it is probably protective, although in what way has yet
to be discovered.
Genus 3.--EREBIA, Dalm.
"Eyes glabrous. Club of antennæ abrupt." (Plate I., figs. 25, 26, and 27
neuration of _Erebia pluto_.)
"An extensive and essentially Alpine genus inhabiting the mountains of
Europe, Asia, North America, and South Africa. Pupa unattached amongst stem
bases of grass."--(Meyrick.)
We have two species in New Zealand.
{114}EREBIA PLUTO, Fereday.
(_Erebia pluto_, Fereday. _Erebia merula_, Hewitson, Ent. Mo. Mag. xii.
10 (1874). _Oreina othello_, Fereday, Trans. N. Z. Inst. viii. 302, 304,
pl. ix. (1876). _Percnodaimon pluto_, Butl., Ent. Mo. Mag. xii. 153
(1876); Catalogue of N. Z. Butterflies, 10.)
(Plate XI., fig. 8 [M], 9 [F], 10 under side.)
This fine butterfly has occurred plentifully on many mountain-tops in the
South Island, from Nelson to Lake Wakatipu. It has never been observed in
the North Island.
The expansion of the wings of the male is 1¾ inches, of the female 2
inches. _On the upper side all the wings are a very rich bronzy-black.
The fore-wings have a paler patch near the apex, containing two small,
and three large black ocelli with white centres_; these ocelli are
usually joined together. On the under side all the wings are considerably
paler and greyer. The hind-wings have a series of pale spots near the
termen, and a paler shade across the middle.
The insect varies chiefly in the number of ocelli. On the upper side of the
fore-wings there are sometimes only four, the minute ocellus on the costa
being absent, whilst occasionally a small extra ocellus appears below the
normal series. On the under side this last-mentioned ocellus is very
frequently, but not invariably, present. In some female specimens an
extremely minute ocellus may be detected on the upper surface of the
hind-wings near the termen. On the under side of the hind-wings in both
sexes the series of pale terminal spots are often absent, and the general
depth of the colouring varies considerably.
Mr. Fereday has described and figured a very interesting variation
occurring in the structure of the costal veins of this species,[54] vein 11
of the fore-wings sometimes running into 12 (see Plate I., fig. 26), and
sometimes being entirely absent (fig. 25). After reading Mr. Fereday's
article I examined the specimens in my own collection, and found that all
those taken on Mount Arthur and on Mount Peel, in the Nelson district, had
veins 11 and 12 joined, whilst the two specimens I took on Mount Enys,
Castle Hill, West Coast Road, had vein 11 absent. As, however, Mr. Fereday
has specimens exhibiting both forms of neuration, from Castle Hill and from
Mount Hutt, I do not think it likely that the peculiarity is confined to
butterflies from any particular locality. Like Mr. Fereday, I have observed
that the specimens having veins 11 and 12 joined, are smaller than those
having vein 11 absent.
The perfect insect appears in January, February and March. It frequents
shingle slopes on mountains, at elevations ranging from 4,000 to 6,000 feet
above the sea-level. Sometimes the butterflies occur in considerable
numbers, flying in a lazy, aimless manner in the scorching sunshine, but
instantly retreating into crevices between the stones when the sun is
obscured. I have observed that this species is most abundant in the
neighbourhood of the carpet grass, on which I fully anticipate its larva
feeds. It seldom, however, settles on this grass, preferring to alight on
the shingle, which, owing to the rarefied air existing at such high
elevations, soon becomes intensely heated by the sun's rays.
When disturbed this insect flies with considerable rapidity and thus often
eludes the net, so that the capture of a good series of specimens on a
rugged mountain-top is usually very exciting, if not actually dangerous
work. As with many other {115}insects, mountain ranges are more prolific in
this butterfly than isolated peaks. Mount Peel, situated to the west of
Mount Arthur, is the best locality I know of for this and many other Alpine
species. Its gentle slopes enable the collector to work with perfect ease
and safety, whilst the patches of rich soil occurring nearly to the top of
the mountain support an unusually varied Alpine flora of great interest.
EREBIA BUTLERI, Fereday.
(_Erebiola butleri_, Fereday, Trans. N. Z. Inst. xii. 264; Catalogue of N.
Z. Butterflies, 19.)
(Plate XI., fig. 11 [M], 12 [F], 13 under side.)
This interesting butterfly was described from three dilapidated specimens
captured by Mr. J. D. Enys at Whitcombe's Pass, Canterbury, on March 8,
1879, at about 4,000 feet above the sea-level. From that time I believe no
other specimens had been found until January, 1894, when I took quite a
large number on the Humboldt Range, at the head of Lake Wakatipu, at
elevations ranging from 4,000 to 5,000 feet above the sea-level.
The expansion of the wings of the male is 1-5/8 inches, of the female 1½
inches. _On the upper side all the wings of the male are smoky-brown; the
fore-wings have a large black ocellus near the apex, enclosing two white
dots, followed by a smaller ocellus towards the dorsum; the hind-wings
have three black spots near the termen, sometimes enclosing white dots._
Occasionally these ocelli are surrounded by a patch of deep
reddish-brown. The female is much paler, with large patches of
yellowish-brown surrounding the ocelli. On the under side the fore-wings
of the male are smoky-brown, with an irregular blotch of reddish-brown
near the apex, surrounding a small white-centred black ocellus. _The
hind-wings are dark reddish-brown, with several conspicuous black-edged
silvery markings, and four yellowish-red spots near the termen._ The
under side of the female is very much paler.
This butterfly varies considerably on the upper side in the number and size
of the ocelli, and in the extent of the reddish-brown markings which
surround them; on the under side the silvery spots on the hind-wings are
also variable.
The perfect insect has been taken in January and March. It evidently
frequents mountains in the South Island, at elevations of about 4,000 feet,
but does not appear to be generally distributed in such localities. It
seldom settles on the shingle, mostly resting on the snow grass, on which
its larva probably feeds. It is a smaller insect than _E. pluto_, and flies
much more feebly. These characteristics will at once enable the collector
to distinguish it from _E. pluto_ when on the wing.
Immediately a cloud obscures the sun these butterflies retreat into the
tufts of the snow grass, remaining closely hidden there until the sun
shines out again. This circumstance makes the capture of the insect, even
in a favourable locality, a matter of considerable uncertainty, as bright
sunshine is more often the exception than the rule on the summits of high
mountains.
Family 3.--LYCÆNIDÆ.
"Anterior legs developed, but tarsi of [M] more or less abbreviated, or
with one or both claws absent; posterior tibiæ without middle spurs.
Fore-wings with vein 7 absent, 8 and 9 stalked or coincident. Hind-wings
without præcostal spur." (Plate I., figs. 15, 16, neuration of
_Chrysophanus salustius_.)
"The family is large and very generally distributed. The species are of
moderate size or more often rather small, usually blue, dark brown, or
coppery-orange in colouring, often with series of small black pale-ringed
spots on lower surface.
{116}"Ovum flattened--spherical or subcylindrical, reticulated and
sometimes ribbed, seldom smooth. Larva stout, with few hairs. Pupa attached
by tail and a central belt of silk, or sometimes unattached or
subterranean."--(Meyrick.)