Mature Jarva. Length, up to 35 mm. Body slightly flattened, tapering posteriorly. Body setae castaneous. Colour white.

Head (Fig. 33) elongate, sides sub-parallel to past mid-length, then tapering and rounded posteriorly. Heavily pigmented to mid-length. Mandible (Figs. 34 and 35) elongate, with two setae, cutting edge oblique, sharply angulate and distally produced into an acute tooth. Clypeus membranous, trapezoidal. Labrum transverse, anterior margin rounded, posterior half pigmented. Maxillary palpi 3-jointed, borne on palpifer with the finger-like mala. First joint of labial palp nearly twice as long as second. Joints of maxillary palp sub-equal in length and decreasing slightly in width. Mentum distinct, short, transverse, with three or four setae on each side. Epistoma with three setae. Apex of labial palpifer with 7 or 8 setae. Front clearly defined by frontal sutures, heavily pigmented and bearing a number of setae. Antennae retractile, antennal ring bisected by frontal suture. One ocellus. Hypostoma with a number of setae extending behind the anterior margin and on each side of the median suture; gular sutures not evident; rising posteriorly to a semi-circular ridge with prominent shoulders laterally at mid-length.

Thorax (Fig. 36). Pronotum transverse, not twice as wide as long, not separated anteriorly from pro-alar area, striate posteriorly. Mesonotum with a row of setae. Metanotum with a double row of tubercles Presternum not separated from epipleurum, setose. Eusternum not very distinct, setose anteriorly. Legs vestigial, reduced to ring of short setae. Spiracles oval, not projecting into prothorax.

Abdomen with epipleurum developed on all segments. Pits not evident on pleural tubercles. Ampullae tuberculate, ventral ampullae with tubercles in two rows. No caudal spine present. Spiracles oval.

Pupa. Form as in adult. Head with three setigerous papillae on each side of vertex between antennal insertions, three large and one small papilla on each side of front between the eyes, three on gena, two on mandible, three on each side of base of clypeus and two small ones on each side of apex of labrum. Pronotum with a continuous row of setigerous papillae across anterior margin, a small sub-circular area of setigerous spines on disc, anterior lateral margins somewhat tuberculate and with setigerous papillae, scattered setigerous papillae in posterior angles. Mesonotum with a semi-circular group of setigerous papillae posteriorly. Metanotum with four or five setigerous papillae on each side. First abdominal segment with a single row of pigmented spines. Segments 2–6 with anterior and posterior rows. Segment 7 with a transverse group of setigerous spines at one-third length and a number posterior to these. Eighth segment with three setae anteriorly on each side, posteriorly with a median conical process with a pigmented point produced dorsad and bearing sephalad on the base two smaller spines; posterior and lateral margins bear on each side about ten pigmented setigerous spines and there are two para-median pigmented spines on the posterior face. Femora with a number of setae on the distal half; none on tibiae. Small processes on the three pairs of trochanters.

This species breeds in abundance in dead Pinus radiata on the Moutere Hills, Nelson, and has been found on the same food plant at Rotorua It has also been found in dead Nothofagus. The pine tree is attacked shortly after death. The female beetle bites an oviposition hole 2–3 mm deep in the bark, inserts her ovipositor and deposits an egg between the bark and the wood. Usually only one egg is laid, but as many as four have been found. When the bark of the pine is more than one quarter of an inch in thickness the female chooses a fissure in the bark in which to make the oviposition hole. The hole is sealed with a secretion after the deposition of the egg. Eggs laid in the laboratory hatched in 19 days. They have been found in the field from October to April. The young larvae bore shallow tunnels between the bark and the wood. Pupation may occur in a shallow cell excavated between the bark and the wood and formed of coarse shreds of wood, or in a vertical pupal chamber 1–2 inches deep in the wood. Pupae have been found from mid-November to the end of February. The pupal period lasted 30 days. The adult emerges from an irregular oval hole in the bark. Adults have been found in the field from October to April. They have been observed to feed on pine bark in captivity The cocoons of the parasitic ichneumonid Mesostenus albopictus Smith have been found in the larval burrows.