Part 7

One of our commonest beetles, found in great abundance {30}in all moist wood when much decayed, the favourite trees being apparently rimu and matai. Its cylindrical larva may be taken in similar situations, and much resembles in general appearance the well-known "wire-worm" of England, whose destructive habits, however, it does not share. At present, whilst bush-clearing is going on, its influence is beneficial, as it devours large quantities of useless wood, which is thus rapidly broken up and got rid of. The pupa is enclosed in an oval cell, constructed by the larva before changing, from which the perfect insect emerges in due course. When first exuded its colour is pale red, but this rapidly changes into dark brown after the insect has been hardened by exposure to the air. Specimens are often met with of every intermediate shade, and are rather liable to deceive the beginner, who mistakes them for distinct species. An account of a small Dipterous insect infesting this beetle in its preparatory states will be found on page 62.

Group LONGICORNIA.

Family PRIONIDÆ.

Prionus reticularis (Plate II., fig. 3, 3b larva, 3a pupa).

This is the largest species of beetle found in New Zealand, and is common throughout the summer in the neighbourhood of forests. Its larva (Fig. 3b) is a large, fat grub, with minute legs; it inhabits rimu and matai, logs, often committing great ravages on sound timber although frequently eating that which is decayed; posts, rails, and the rafters of houses alike suffer from its attacks; the great holes formed by a full-grown larva of this insect creating rapid destruction in the largest timbers. It may be remarked, in connection with these wood-boring species, that a good thick coat of paint put on the timber as soon as it is exposed, and renewed at frequent intervals, to a great extent prevents their attacks. The pupa (Fig. 3a) {31}is enclosed in one of the burrows formed by the larva, which, before changing, blocks up any aperture, so as to rest secure from all enemies. The perfect insect emerges in the following summer, when it may be often observed flying about at night. It is greatly attracted by light, and this propensity frequently leads it on summer evenings to invade ladies' drawing-rooms, when its sudden and noisy arrival is apt to cause much needless consternation amongst the inmates.

Closely allied to the above is Ochrocydus huttoni, which may be at once known by its smaller size and plain elytra; it is very much scarcer than P. reticularis, but may occasionally be cut out of dead manuka trees in company with its larva.

Group RHYNCOPHORA.

Family CURCULIONIDÆ.

Oreda notata (Plate II., fig. 4, 4a larva).

This weevil is not often noticed in the open, but may be found in great abundance in the dead stems of fuchsia, mahoe, and other soft-wooded shrubs, whose trunks are frequently noticed pierced with numerous cylindrical holes. The larva also inhabits these burrows, devouring large quantities of the wood; it is provided with a large head and powerful pair of mandibles, but, in common with all other weevil larvæ, does not possess legs of any description, the insect being absolutely helpless when removed from its home in the wood. The pupa might also be found in similar situations, but I have not yet observed it. The perfect insect may be cut out of the trees throughout the year, and is occasionally taken amongst herbage during the summer.

Family CURCULIONIDÆ.

Psepholax coronatus (Plate II., fig. 5 , 5a ).

This curious species is found abundantly in the stems of {32}dead currant trees (Aristotelia racemosa), in which it excavates numerous cylindrical burrows like the last species, which it closely resembles when in the larval state. The sexes are widely different, the elytra of the male being furnished with the characteristic coronet of spines, which is entirely wanting in the female. Numerous other members of this genus may be taken in company with the present insect, and should be carefully examined, as a correct determination of the males and females of the several species is sadly wanted. Digging beetles out of the wood is good employment for the entomologist in winter, when he will find that a day spent in this manner will frequently produce as rich a harvest as one in the height of summer.

Before finally leaving the Coleoptera, I should like to direct the attention of my readers to the immense number of interesting weevils found in New Zealand. Chief among these is the remarkable Lasiorhynchus barbicornis, a large insect furnished with a gigantic rostrum, which will at once distinguish it from any of the rest. Other genera contain numerous beetles, which may be found in various kinds of dead timber in company with their larvæ, and are worthy of a more minute investigation than has at present been given them.

{33}CHAPTER IV

The Hymenoptera.

The Hymenoptera are perhaps the most interesting order of insects, their brilliant colours, great activity, and unparalleled instincts rendering them alike attractive to the young collector and scientific entomologist. They are, however, not very numerous in New Zealand, several of the most important families being completely absent; in fact, with the exception of the ants, there are no social Hymenoptera native to this country. The information I here give in connection with these insects does not adequately represent the large amount of interest which can be derived from their investigation, and I must therefore refer the reader to those admirable works by Sir J. Lubbock on Ants and by Huber on Bees, which cannot fail to interest all who read them.

Family ANDRENIDÆ.

Dasycolletes hirtipes (?) (Plate III., fig. 1).

This is the true native bee of New Zealand, and may be taken abundantly during the whole of the summer. Its nest is constructed in crevices in the bark of trees, &c., the insect very frequently selecting the spaces between the boards of outhouses, where the loud buzzing noise {34}made by the perfect bees when emerging from their retreat at once arrests our attention. These nests consist of about ten oval cells, formed of clay, and neatly smoothed within. They are all constructed by a single female, which also provisions them with honey and pollen, depositing an egg in each. The larva, after consuming the food, changes into a pupa, from which the perfect insect emerges about January. If the reader will imagine a great number of these nests closely packed together, the formation and storing of the cells being performed by a number of sterile individuals (workers), while the eggs are deposited by a single female (queen), he will have a fair idea of the economy of the social bees and wasps, whose wonderful instincts attain their maximum in the well-known hive-bee, successfully introduced and cultivated in various parts of the country.

Closely allied to this species is Dasycolletes purpureus (?) (Fig. 10), which forms its nests in sand-banks, its cylindrical holes having a great resemblance to the burrows of Cincindela tuberculata, which frequently occur in the same situation.

Family SPHEGIDÆ.

Pompilus fugax (Plate III., fig. 2).

This is a very abundant insect, and may be observed flying about on any fine day during the summer, occasionally stopping to examine leaves and crevices in the bark of trees, where it is looking for the unfortunate spiders, which constitute the food of its progeny. The larva is a fat apodal grub, and may be found in the cells constructed by the perfect insect, which usually selects a large cylindrical hole in a log, previously drilled out by a weevil. Into this burrow she pushes a large quantity of spiders, which she has previously captured and paralyzed with her venomous sting. When her nest is {35}properly provisioned she deposits an egg in it, closes the hole with a neat plug of clay, and leaves the larva to quietly consume its half-dead companions. Each female, no doubt, forms a large number of these cells during the summer. While cutting up old logs for Coleoptera, the entomologist will not infrequently come across these nests, when the insects may be found in various stages of development. Unfortunately, however, the sight which usually meets his eye is a large number of legs and other fragments of spiders, the fugax having long since deserted the burrow, and being very probably engaged in forming others in a neighbouring tree. These insects are very ferocious, and will attack spiders which considerably exceed them in size. On one occasion I noticed a very large one at rest in the centre of its web, which was suddenly noticed by a passing fugax, which immediately sprang upon its back, and, in spite of violent movements on the part of the spider, twisted her abdomen dexterously round and stung her victim in the centre of the thorax, between the insertions of the legs. This produced almost instantaneous paralysis in the spider; but it was apparently too large for the fugax to carry away to her nest, as I saw the unfortunate creature hanging helplessly in its web some hours after the occurrence.

Family FORMICIDÆ.

Formica zealandica (Plate III., fig. 3 , 3a , 3b , 3c, cocoon).

This is one of our commonest ants, and may be noticed under logs and stones throughout the year. The nest consists of a number of irregular cavities dug out by the workers either in the ground or in soft rotten wood. Its size varies considerably, but the societies of this species are not usually so extensive as those of Atta antarctica, {36}an insect I shall have occasion to refer to presently. The larvæ are minute apodal grubs, which are dependent entirely on the workers for food. When full grown they spin an oval cocoon of white silk, in which they are converted into pupæ, and these the patient neuter ants may be observed carrying away with great anxiety when disturbed, risking their own lives to preserve their adopted offspring from destruction. The females, or queens, of which there are several in each nest, do not appear to participate in these labours, but are only instrumental in perpetuating the species, and the same remark applies to the males. A large number of these winged males and females may be observed in the nests about February, the general emergence taking place during that month. At this time they leave their native homes and mount to a great height in the air, and after sporting for some hours they re-alight on the earth, and in a short space of time cast their wings. The neuters at this time are said to carry them away to form fresh colonies, but I have not carried my investigations sufficiently far to verify this in connection with the New Zealand species.

Family FORMICIDÆ.