Art. X.—On the Wetas, a Group of Orthopterous Insects inhabiting New Zealand; with Descriptions of Two New Species.
[Read before the Wellington Philosophical Society, 19th September, 1894.]
In Gray's “Zoological Miscellany,” 1842, p. 78, there first appeared a description of the great forest Weta of New Zealand, under the name of Deinacrida heteracantha, White. A further account of this remarkable insect was given in the List of the Fauna appended to Dieffenbach's “Travels in New Zealand,” from which I extract the following; “The length of the specimen brought by Dr. Dieffenbach, measuring from the forehead to the end of the abdomen, exclusive of appendages, is 2in.; from the end of the tarsus of hind leg to end of antenna stretched out, this specimen measures at least 12 ½ in. The specimen may be in the larva state. The praesternum, as in Anostostoma, with two spines approximating in the middle; meso- and meta-sternum deeply grooved behind, with a strong tooth on the sides behind. Dr. Andrew Sinclair, since my short description was published in the second part of Mr. Gray's Miscellany, has brought from New Zealand a specimen of this species which, with its hind legs and antennae stretched out, is at least 14in. long; its head and body, exclusive of appendages, being 2 ½ in. The specimen is a female; its ovipositor is rather more than 1in. long is slightly bent upwards and compressed through the greater part of its length, the two cultelli forming its principal part being somewhat angular at the base. Nearly the whole insect is of an ochry-yellow colour, the end of the ovipositor and the extreme tip of the spines on the legs being brown; the margins of the abdominal segments are of a lighter colour; the transversely – ridged and rough – surfaced femora have many light-coloured streaks. The greater portion of the dorsal part of the thorax is somewhat ferruginous. This specimen was found by itself on the marsh-pine in Waiheke, in the Firth of the Thames. Five other specimens of smaller size Dr. Sinclair found congregated under the bark of trees.”*
The last-mentioned specimens belonged, no doubt, to the species afterwards described as Deinacrida (Hemideina) thoracica, White (Voy. Ereb. and Terr., Ins., 1846).
[Footnote] * Op. cit., vol. ii., p. 280.
In 1867 I published in the “Zoologist,” page 850, the description of a new species, Hemideina megacephala, Buller, distinguished by its enormous head.
In 1869 ten more names were added to the group, namely: Hemideina producta (afterwards referred by Professor Hutton to H. thoracica),* H. capitolina, H. figurata, H. abbreviata, H. tibialis, Ceuthophilus (?) lanceolatus, Macropathus filifer, M. fascifer, and M. altus (White, Cat. Locustidae); also Hadenoecus edwardsii (Scudder, Proc. Boston Soc. of Nat. Hist., xii., p. 408).
In 1870 I communicated a paper to this Society (Trans. N.Z. Inst., vol. iii., pp. 34–37) in which I republished my account of Hemideina megacephala, and described a new species under the name of Deinacrida rugosa, Buller (with figures of both).
In 1880 Mr. Colenso described (Trans. N.Z. Inst., vol. xiv., p. 278), under the name of Hemideina gigantea, “a species bigger in every way than D. heteracantha,” adding, “it is also much more spiny, and differs greatly in colours,” &c. He at the same time described (tom, cit., p. 240) another species, Hemideina speluncae, giving as its habitat “dark underground caves near the head of the Manawatu River, in the Forty-mile Bush.”
Respecting the first-named of these Mr. Colenso gave some very interesting historical particulars.
An admirable figure of Deinacrida heteracantha appeared in the “Zoology of the ‘Erebus’ and ‘Terror,’” part “Insects,” p. 24, pl. 5, fig. i.; and in 1868 Professor Hochstetter published a good figure in outline (“New Zealand,” p. 170), with a brief and somewhat inaccurate account of the insect, concluding with this remark: “Despite its hideous looks it is perfectly harmless.”
Mr. Colenso stated in 1880 (l.c., p. 280) that his unique specimen of Hemideina gigantea had then been forty-two years in spirits with its colours unaltered, the liquid in the glass bottle containing it being still clear and pure. To this we must now add thirteen years more; so that the specimen has been canonized for more than half a century. I think the beautiful female specimen of Deinacrida heteracantha in my son's collection can show almost as good a record. It is amongst the earliest recollections of my life that, about forty-five years ago, wandering through the woods at Tangiteroria with my private tutor, Dr. Beard, we found this huge Weta at the foot of a tree, and brought it home in a silk pocket-handkerchief. Being something of a naturalist, the doctor carefully
[Footnote] * “Catalogue of the New Zealand Diptera, Orthoptera, Hymenoptera,” 1881, p. 82.
stuffed the insect and placed it in a small glass show-case of his own construction, where it has remained hermetically sealed ever since. It had perhaps a better chance than the specimen in spirits of preserving its colours, and it is now as fresh and bright as the day it was stuffed. I remember that some years later, in riding through a strip of bush between Mangakahia and Whangarei, I caught a pair of them on a low tree, where they were apparently feeding on the young leaves. Dismounting from my horse, I secured the two Wetas in a pocket-handkerchief, and hung them up in a tree to await my return a day or two later. On coming back, however, I found that they had eaten their way out and made their escape.
For many years this fine insect has been looked upon as extinct, and it certainly is extremely rare; but since my last return from England I have been fortunate enough to secure the large male specimen now on the table. I purchased it from a dealer in Auckland, who told me he had procured it from one of the small wooded islands in the Hauraki Gulf. Formerly it was very abundant in all the woods at the far north; but I never heard of its being found south of the Waikato district. The Maoris attribute its disappearance to the introduced Norway rat. They distinguish it as the Wetapunga.
In 1884 Mr. Colenso (op. cit., vol. xvii., p. 155) added another species, under the name of Deinacrida amiger, from Wairoa, Hawke's Bay District, stating that it seemed allied to H. megacephala. In 1886 he described (op. cit., vol. xix., p. 145) Hemideina longipes, from a specimen obtained in a totara forest at Norsewood, in the County of Waipawa. Finally, in 1888, he described, under the name of Hemideina nitens, “a peculiar species, differing from other described ones in its general very dark colour, extreme glossiness,” &c.
It will be seen, therefore, that Mr. Colenso has added no less than five species to the list. I have not had an opportunity of examining any of his types, and cannot therefore express any opinion as to the value of his specific characters. After a careful study, however, of his descriptions, I am satisfied that none of them apply to the fine insect which I have the pleasure of exhibiting to-night, and for the loan of which I am indebted to Mr. Teutenberg, of Auckland. He informed me that he obtained it at Coromandel, but he could give me no particulars respecting it. Judging by its character, I should say it is an inhabitant of caves or overhanging rocks.
Genus Macropathus, Walker.
Macropathus maximus, sp. nov.
Male.—Body stout, convex, smooth, not shining. General colour rich tawny-brown, darker on the joints, and deepening
to reddish-brown on the hind tibiae; changing to yellow on the face, front tarsi, and greater part of antennae. Head short fore part vertical. Eyes prominent, rounded, and blackish-brown in colour, as is also the slightly-polished vertex. Maxillary palpi long and slender; the fourth joint somewhat longer than the third; the fifth appreciably longer, and distinctly subclavate. Labrum prominent; labial palpi clavate at the tip. Antennae extremely long and slender, being more than six times the length of the body; the first joint much thickened, the rest smooth and even, being entirely free from the minute knobs and spines that occur on the antennae of Macropathus fascifer. Prothorax well covered with shield, which is broadest behind, the lower border being slightly reflexed. Mesothorax and metathorax presenting broad, even segments; the eight abdominal dorsal segments much narrower, closely set, and gradually diminishing in size towards the extremity; cerci of moderate length and beset with fine hairs, especially towards the base. Abdomen short, slightly compressed. Legs slender, extremely long, and very spiny; hind femora greatly swollen towards the base; knees nodose. The four anterior femora have spines beneath, but the number is uncertain: thus, of the first pair the right-hand femur has four spines, and the left-hand femur five spines; of the pair behind, the right femur has two on one side and five on the other, whilst the left femur has three on each side; the hind femora, on their channelled posterior surface, have twelve to thirteen sharp spines, set well apart, on one side, and twenty-three to twenty-five small closely-set ones on the other side. So also with the tibiae: the first pair have each five extremely fine spines, or rather spurs, on each side, the apical ones being the longest; of the next or middle pair the right-hand tibia has three on one side and four on the other whilst the left-hand tibia has three on one side and two on the other. The hind tibiae are armed with a regular double series of sharp, slightly-decurved spines, exactly resembling the thorns on a rose-bush, those towards the base being extremely minute, and the apical or terminal ones very long; the right-hand tibia has twelve on one side and fourteen on the other, whilst the left-hand tibia has twelve on one side and eleven on the other. It will be seen, therefore, that the number of spines is a very uncertain character. The body, without the appendages, measures exactly 1in. in length and 0.4in. in its widest part; the hind femora measure 2in., and the hind tibiae 2.25in.; the cerci, which are slightly curved upwards, measure 0.3in.; and the antennae 6.25in.
I have made this Weta the representative of a fourth group of Walker's genus Macropathus. It may, however, be necessary to make it the type of an entirely new genus. It differs
from the typical Macropathus in having a dull or plain, and not a shining, surface; and, like Deinacrida, it has ten dorsal segments behind the thoracic shield, instead of eight as in M. fascifer. It has fine and slender antennae, in which respect also it comes near to Deinacrida,; it has numerous spines on the four anterior femora, whereas M. fascifer has only two; and, whilst the latter has only four or five minute spurs on the inner edge of the hind femora, with ten on the outer edge, this form has both sides spiny in their whole length.
Hab. North Island.
Genus Deinacrida, White.
I have now to describe another new species of Weta, which has been in my son's collection for some years. It was obtained by Mr. J. Brough in the Nelson Provincial District, and sent over preserved in spirits. Unfortunately the antennae are wanting, but in every other respect the specimen is perfect. It seems to belong to the genus Deinacrida, and comes nearer to my Deinacrida rugosa than to D. heteracantha; but it is very small, even as compared with the former, and has other distinguishing features.
I exhibit this rare specimen alongside of the larger species. In addition to its diminutive size, it will be seen that the dorsal segments, or dermal plates if I may so term them, have a peculiar emarginate character, presenting the appearance of of a miniature coat of mail.
Deinacrida parva, sp. nov.
Male.—Body rounded above, somewhat compressed on the sides. Head slightly punctured on the vertex; thoracic shield more distinctly punctured; of the ten dorsal segments behind it, the two first have a slightly roughened surface, and the six abdominal ones are distinctly emarginate in the middle, with almost imperceptibly raised edges. Legs somewhat shorter in proportion than in D. heteracantha. Labial and maxillary palpi clavate at the tips. Cerci minute. Four anterior femora free from spines. Tibiae quadrangular, both the inner edges armed with sharp spines. Hind femora similarly armed; hind tibiae broader behind than on the sides, and furnished with sharp spines coming out alternately; their posterior edges also armed with minute spurs. General colour ochre-yellow; the thoracic shield dull reddish-brown, and the abdomen beneath darker. Length of the body, without appendages, 1.1; hind femora, 0.75; hind tibiae, 0.75; tarsus and claws, 0.30.
Hab. South Island.