WAYS OF THE WILD.

Auckland Star, Volume LX, Issue 40, 16 February 1929, Page 1 (Supplement)

WAYS OF THE WILD.

A NATURALIST'S NOTEBOOK.

THE HUHU GRUB.

(By A. T. PYCKOFT.)

This Maori delicacy was recently tha hors d'oeuvre and the subject of conversation at dinner one evening when camping at Mr. M. H. Miller's bush house at Waitakere, overlooking Piha, Although probably repugnant to the majority of Europeans, thii woodboring grub, huhu, is a delicacy of which the Northern Maori was very fond. The writer and his friends found it very palatable and of a rich nut-like flavour. It is the grub of our largest beetle—the length of the body of the grub is three inches and that of the beetle an inch and a half. The beetle is commonly known as the huhu beetle and is one of the round-headed borers, or longhorns. To the Maori the beetle is known at kapapa, and to the scientist as Prionoplua rebticularis. The beetle was seen at dusk, its droning flight sound being clearly audible. The grub was found to be plentiful in a dead miro stump near the house and it was from this-source our entree was obtained. One perfect young beetle, or imago, was also obtained. How to Distinguish a Beetle.

Beetles are readily distinguished by the hardened fore wings forming a pair of covers, or cases (elytra), which close over the body, only the fore part of ths thorax remaining exposed, and beneath which the membraneous hind wings are folded.

The long-horned beetles (Ceranibycidae), to which family the huha belongs, comprise a very large family of wood borers, and there are a great many native species in the Dominion. The beetles themselves are readily recognised by their very long antennae, in some species longer than the body, which ii more or less elongate, often narrow, usually cylindrical. Some are amongst the largest insects, while others are comparatively small. A number of them are powerful flyers and emit a loud droning when on the wing, being frequently attracted to lights at night. Others, again, are more or less sluggish and remain motionless even when roughly disturbed. Several species when at rest create a distinct but faint squeak much like that made by an India rubber squeaking doll. The stridulating organ of these beetles is situated on the back and consists of a triangular process projecting forward under the front part of the thorax from the middle of the bodv, where the wing cases are attached. The inner surface of the front part of th* thorax is drawn over the point of this process and creates the characteristic squeak. Other species create a raspinu sound by rubbing the hind thigh against the edges of the wing cases.

A Beetle's Life History. i. %*% histt>ry of a t sT iical beetl « is nrst the emergence from the egg of the larva, that is the state bearing gone resemblance to that of the catlrpillar of the butterfly or moth. » T £fl- L ar^ a J en, MM in this stage ior *&&&<* three : or«ve years in solid wood, before it attains its full growth. It is chiefly during this stage of an insects existence, according to the mode of the life of the members of the group or germs to which it belongs, that it commits so much havoc, or proves of great service to man. It later becomes a papa, that is, a state which correspond, to a chrysalis in Lepidopterous insects. In this state the beetle is generally soft, and quite narmless, that is it does not take any kind of substantial nourishment, and, though inactive, is in reality undergoing important changes. Now, for the first time may be seen the result of those marvellous transformations which have occurred since the female laid the egg, as the form and structure of the imago, or perfect insect, can clearly be traced.

The beetle issues from the pupa staff* during autumn, or spring, in the former case generally remaining quiescent during the winter, and in the vast majority of cases, is short-lived, appearing indeed to exist no longer than is necessary for the propagation of the , species.

It is evident, therefore, that the imago does comparatively little injurv, whilst many of the predacious Toundbeetles, which frequently live throughout the spring and summer, destroy vast numbers of insect pests. The eggs of the huhu beetle are laid m crevices, under dead bark, or in old burrows in dead trees. During egglaying the female moves over the tree feeling the surface with the mouth appendages, and, having selected a suitable place for depositing the egga. tae terminal segments of the abdomen, which are withdrawn when not in use, are extended as a slender appendage. The latter has a sensitive tip, and is used to search for the exact spot for the deposition of the eggs, which are cigarshaped and white in colour. The larvae on hatching bore Immediately into the wood, and in healthy wood, confine their attention to the sap wood. However, as time goes on the heart i\ood is attacked and tne timber reduced to powder. As the eggs are laid in batches, the larvae commence their attacks from tnese points, and radiate in all directions. .Acording to Dr. D. Miller, the disintegration of timber by this insect is comparatively slow. A curious feature is that the larvae of this beetle shows no external signs of its presence except for the large oval exit-holes of the adults.

The huhu prefers to commence its depredations in the area between the aeart and sap wood. Thy full-growu huhu is white in colour, and greasy vj the touch. It measures fully three inches long, and the body-segments arc well defined, there are "three pairs or very small legs, while the head is snial. and brownish-black. As the iar\at> works its way through the wood it cuts a burrow, oval in cross-section, a:.d packs this with the undigested portions of the wood it has devoured. No matter how deep into a log the larvae burrows, it works its way to the near surface in order to pupate, and the beetle on emerging cuts its way out.

The huhu aitacke dead trees, and is found in riiuu, matai, miro, kahikatea kauri, insignis pine, and oak. Hudson states "Manual of New Zealand Entomology ," that thU beetle often commit great ravages on sound timber; poste" rails, and the rafters of house* alike suffer from its attacks, and that thegreat holee formed by a fuLI-grown larvae of this insect creates rapid destruction in the largest timber.