Howickia nigrilegula Marshall

Marshall, S. A., Luk, S. P. L. & Dong, H., 2014, A revision of the New Zealand species of Howickia Richards, Zootaxa 3887 (1), pp. 1-36 : 17

Howickia nigrilegula Marshall sp. nov.

( Figs. 11, 12 , 44)

Description. Colour: Thorax and abdomen subshining black, sparsely microtrichose. Upper and lower margins of face silvery pruinose, lower band continuous with a conspicuous narrow silver strip across upper gena; indentation at anteromedial eye margin also silvery pruinose, continuous with similar silver area of upper face. Lunule dark at middle, silvery along upper margin, and silvery along lower margin contiguous with silvery band of upper face. Middle of face bare and shining. Legs mostly brown with orange knees, tarsi reddish brown.

Head: Orbital bristles absent but minute orbital setulae present. Ocelli very small, anterior ocellus difficult to distinguish from surrounding silvery microsetulosity. Eye 2.0X genal height. Vibrissa strong, anterior genal bristle subequal to subvibrissa, slightly longer than other genal bristles. Face tuberculate between antennae, slightly concave at middle. Pedicel with several bristles along distal margin and with a large inclinate dorsal bristle. Arista with relatively long hairs, hairs at least twice as long as width of first aristomere.

Thorax: Scutum with single postpronotal, notopleural, supraalar, postalar and prescutellar dorsocentral bristles; postalar and apical scutellar bristles subequal, basal scutellars much shorter and dorsocentrals much longer. Acrostichal setulae uniformly small. Scutellum sparsely microtrichose, shining, 3.0X as wide as long. Wing shining brown, broadly oval (earlobe-shaped), veinless, slightly shorter than scutellum; halter absent.

Male abdomen: Sternites 2–5 of similar dimensions, sternite 5 concave and pale medially, medial area with dense small bristles; sternite 4 unmodified. Subanal plate complete but pale; lower/outer part of cercus broadly rounded. Surstylus without stout spurs or long bristles; main body of surstylus subquadrate with a small, fingerlike, ventrally directed anterior lobe. Distiphallus narrow, tubular. Postgonites narrow, straight. Basiphallus framelike, projecting posteriorly slightly from distiphallus base.

Female abdomen: No females were dissected, and none of the available females have the ovipositor everted.

Type material. Holotype (male, NZAC) and one paratype (male, NZAC): New Zealand, Trounson Kauri Park, 11 km S of Waipoua SF, 6–16.Dec.1976, pit trap, B.M. May. Other paratypes: Same locality as holotype but 27.Jan.1999, S.A. Marshall (1 male, DEBU); Waimatenui, leaf mould, 3.Mar.1962, R.A. Cumber (2 females, NZAC); Brynderywyn, 22.Jul.1966, R.A. Cumber (1 female).

Etymology. Howickia nigrilegula is named for the darkly pigmented, earlobe-shaped wing rudiment.

Comments. This species, easily recognized either by the very distinctive surstylus or the external characters given in the key, is known only from a few specimens at three nearby sites in Northland. It is likely to be restricted to leaf litter in old growth Kauri forest.

Figures

FIGURES 9 – 14. Howickia trilineata group, plate 2. Howickia trilineata (Hutton): 9, habitus; 10, head. Howickia nigrilegula Marshall, sp. n.: 11, habitus; 12, head. Howickia nigriventer Marshall, sp. n.: 13, habitus; 14, head.