By E. S. Gourlay, First Assistant Entomologist, Cawthron Institute, Nelson.

[Read before the Nelson Institute, 1st December, 1926; received by Editor, 9th December, 1926; issued separately, 6th August, 1927.]

(Plate 2.)

In the Tenthredinoid group of the Hymenoptera, New Zealand has endemic representatives of the families Xiphydriidae and Oryssidae only. Of the Xiphydriidae there is one species, Xiphydria decepta Smith, and of the Oryssidae there is one species, Ophrynopus schauinslandi Ashmead. In 1901, the latter insect was described from the Chatham Islands, and the writer (1925) added to the record instances of its occurrence on the mainland of New Zealand. X. decepta is rare, and but for one notable instance recorded in 1925, the same remark applies to O. schauinslandi.

The species described hereunder brings the total number of Tenthredinoid Hymnoptera to three, and it would appear that all are subalpine.

Family Xiphydriidae.
Genus Xiphydria.
Xiphydria duniana n. sp.

♀. 8 mm. Head shining, black, except mandibles which are castaneous, the teeth black, and palpi, brown, greatly suffused with black; clypeus, cheeks, scape, palpi and mandibles, covered sparsely with moderately long amber-coloured hairs, longest and thickest on the cheeks. Clypeus overlapping mandibles laterally, having a small sharp triangular tooth medially. Frons, between the antennae, conical, flattened above, and having a depression medially which ends at the anterior ocellus. Antennae 20-jointed, lying in a broad vertical furrow, widest at the insertion of the antennae, and narrowing just above them to continue as a shallow fossulet to the lateral ocelli. Thorax black dorsally, shining; brownish laterally and ventrally, more or less suffused with black, the base of the episternum black. Pronotum and episternum covered with long pale brown hairs, the lateral angles of the former yellow. Parapsidal grooves and a median longitudinal groove on the scutum deeply pitted, the former wide, the latter narrow. Scutellum flat, with steeply declivous sides. First abdominal spiracles large, prominent. Wings hyaline, highly iridescent, the nervures and stigma dark brown. Legs dark brown, suffused with black, the latter colour being present in greater proportion in the fore coxae, trochanters and femora. All the coxae slightly hairy; the hind tibiae and tarsi densely clothed with moderately long pale brown hair. Abdomen black dorsally, brown suffused with black ventrally, shining. Laterally, a cream spot on segments four, five and six, and a large oblique cream mark on segment nine. On each of sternites four to eight a row of pale brown hairs; segments nine and ten have a patch laterally. Sheaths of ovipositor also hairy, dark brown suffused with black.

Taken resting on Uncinia sp. growing in the open and close to a large clearing among mixed Nothofagus forest.

One specimen, from “Third House,” Dun Moutain, 2,000 feet, in February, 1926. Holotype (♀) in Coll. Cawthron Institute.