Art. VIII.—Notes on the Genus Deinacrida in New Zealand. (With Illustrations.)
[Read before the Wellington Philosophical Society, November 12, 1870.]
[A Poetion of the following notes on a curious group of New Zealand insects appeared in the Zoologist for August, 1867. It has been considered advisable to reprint the paper after revision by the author, who now adds the description of an additional species.—Ed.]
1. Deinacrida heteracantha, White. (“Weta-punga” of the natives.)
This fine species has a very limited geographical range. I have never heard of its occurrence south of the Waikato District, in the North Island. Formerly it was abundant in the forests north of Auckland; but of late years it has become extremely rare. The natives attribute its extermination to the introduced Norway rat, which now infests every part of the country and devours almost everything that comes in its way. One of these insects, in the collection of the late Dr. Sinclair, measured, with its hind legs and antennæ stretched out, fourteen inches; its head and body, exclusive of appendages, being two inches and a half. A specimen which I obtained in a pine forest, near the Kaipara River, more than thirteen years ago, and which is now deposited in the Auckland Museum, is even larger. The sexes differ considerably in size.
The Weta-punga appears to subsist chiefly on the green leaves of trees and shrubs. It climbs with agility, and is sometimes found on the topmost branches of the kabikatea and other lofty trees, but more generally on the low under- wood of the forest. When disturbed it produces a clicking noise, accompanied by a slow alternate movement of its powerful hind legs. When taken it kicks or strikes backwards with these limbs, which are armed with double rows of sharp spurs; and, unless dexterously seized, will not fail to punish the offender's hand, the prick of its spurs causing an unpleasant stinging sensation. My brother-in-law, Major Mair, obtained some exceedingly fine examples of this insect in the Whangarei District. He found the killing of them, so as not to injure the specimens, a matter of some difficulty; and in one instance attempted to drown the insect in cold water, but found it after four days' immersion as lively and active as ever. In another case, a large Weta-punga which he had immersed in water almost boiling, and then laid aside in his insect-box as killed, revived in the course of a few hours, and appeared to be quite unharmed! A pair which I captured in a low belt of wood near the Wairoa, and secured in a pocket handkerchief, had eaten their way out and escaped before my return to the spot where I had left them carefully suspended.
2. Deinacrida thoracica, Gray. “Weta” of the natives.)
This species is very common in the North Island. It infests decayed wood, and particularly the dry stems of the tutu (Coriaria ruscifolia) and the branches of Griselina lucida, into which it bores. During the night it may be heard emitting a peculiar snapping sound, especially when disturbed by the blaze of a camp fire in the woods.
The male may be readily distinguished from the female by its large head and long powerful jaws. The ovipositor (in the female) is about half an inch
long, and is slightly recurved. This insect is preyed on by the koheperoa (Eudynamis taïtensis), the kaka (Nestor meridionalis) and several other birds.
3. Deinacrida megacephala, Buller. (Zool., 1867, p. 852.)
I bestowed this name on a new species, of which I had received several examples (of both sexes) from the woods in the neighbourhood of Wellington. The male of this species is characterized by a head and mandibles so large as to appear out of all proportion to the size of the body. (Figure 2, Plate V.b.) This exaggerated feature is wanting in the other sex, which, however, is distinguishable from Deinacrida thoracica by sufficiently obvious specific characters. The tibiæ are considerably thicker, and more strongly armed with lateral spurs, although not longer than in the other species; the thorax, which is ochreous- yellow marked with black in D. thoracica, is of uniform dark umber, narrowly margined with brown; the head of this species is almost entirely black, and the body, instead of being pale brown, as in the other, is deep reddish brown with transverse bands of black. The femora are marked on each side with three series of minute black spots, which are more conspicuous in the male. The following are the measurements of the male:—Head and mandibles, one inch; from anterior edge of thorax to end of abdomen one inch and three-sixteenths, the plate of the thorax measuring a quarter of an inch. The antenné are four inches long; femur three-quarters of an inch; tibia one inch and three-sixteenths; tarsus and claws three-eighths of an inch. The vertex is much rounded or elevated, and perfectly smooth.
4. Deinacrida rugosa, sp. nov. (Figs. 1 and 3, Plate V.b.)
I propose this name for a species of which one example only (now deposited in the Colonial Museum) has yet been obtained.
This species is intermediate in size between D. heteracantha and D. megacephala, and possesses very distinct characters. The extreme length of the body is 1¾ inches, the thoracic shield measuring half an inch in length by three-quarters in width (following the curvature). Although a male specimen, the head is very small and rounded, measuring only half an inch in length, by three-eighths in width. The eyes are large and very prominent; the antennæ comparatively short, measuring scarcely four inches. Femur one inch; tibia one inch; tarsus and claws, half an inch. The edges of the thoracic shield are raised, and the surface is deeply punctured and indented. The posterior edges of the dorsal plates are raised, and the lower ones have a fringe of hard papillæ along their outer margin. All the plates are more or less punctured, and the whole surface presents a roughened appearance, which at once distinguishes the species from D. heteracantha, to which it more nearly approaches. Head, thorax, and body bright reddish brown, the edges of the plates darker;
thoracic shield and two succeeding plates marked with black. Antennæ and legs yellowish brown, the joints of the latter spotted with black. Under parts yellowish brown, darker on the edges of the abdominal segments.
My specimen was obtained in the Wanganui District, and was found underground.