Howickia oliveri 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 : 20

Howickia oliveri Marshall sp. nov.

( Figs. 2–4 , 46–48 )

Description. Colour: Thorax and abdomen dull brown, densely microtrichose. Head brown to reddish brown. Face and gena microtrichose except for a bare anterodorsal patch on the gena. Legs mostly brown with orange knees, tarsi dirty white to yellowish.

Head: Interfrontal bristles in 3 pairs, upper 2 large and slightly cruciate. Two orbital bristles, upper orbital bristle large, lower small. Ocelli large, ocellar triangle raised and distinct. Eye 2.5–2.8X genal height. Vibrissa strong, subvibrissa small, anterior genal bristle large. 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 dorsocentral bristles subequal; basal scutellars shorter, half as long as apical scutellar bristles. Acrostichal setulae uniformly small. Scutellum microtrichose, 2.0X as wide as long. Wing and halter well developed; wing almost uniformly infuscated, with pale areas along hind margin and along a distinct longitudinal fold running up the middle of cell dm. Vein R2+3 very short, running almost directly to costa, slightly sinuate; R4+5 gently turned up to costa, costa bypassing apex of R4+5 by several vein widths. Halter stem white, knob rounded and dark anterodorsally, white posteroventrally, uniformly microtrichose.

Abdomen: Syntergite 1+2 separate laterally, entirely fused medially and equal in length to tergites 3 and 4.

Male abdomen: Sternite 5 as long as sternite 4, posteromedial area with a pale concavity margined with 4 prominent black teeth on posterior edge. Sternite 7 (unlike all congeners except H. lepidostylus ) prominently forked at ventral apex. Subanal plate broad; lower/outer part of cercus projecting ventrally as small point. Surstylus with a short, subquadrate posterior lobe and a much larger, ventrally projecting anterior lobe with an anteriorly bent, bifid apex. Distiphallus narrow, tubular. Postgonite narrow, almost straight, slightly tapered distally, posterior surface flat. Basiphallus frame-like, projecting posteriorly at right angle to distiphallus base for a distance equal to distiphallus base.

Female abdomen: Tergite 8 divided into 3 parts anteriorly but connected posteriorly, dorsal (middle) part shining bare, lateral parts setulose and setose posteriorly. Epiproct very small, 0.25X as long as tergite 8, pale medially and bare except for 2 setae. Cerci small, entirely setulose and setose, similar in size to epiproct. Spermathecae spherical, ringed with weak transverse striae, paired spermathecae with duct section from junction to bulb slightly longer than bulb. Sternite 8 darker than other sclerites, triangular, tapered anteriorly and setulose except for dark, tab-like posterior margin. Hypoproct divided into a bare anterior plate and a setulose posterior plate.

Type material. Holotype male ( NZAC): New Zealand, Moehau, Okahutahi Stream, liver bait trap, 21–25.Apr.1984, H. Oliver. Paratypes (140 males) same locality as holotype, but taken in water traps and Malaise traps ( DEBU, NZAC).

Other material examined. About 150 females, same locality as paratypes ( DEBU). Etymology. This species is named for friend and colleague Hugh Oliver, who provided a rich collection of Howickia , including the entire long type series of H. oliveri .

Comments. Although this species is known from a large collection of about 300 specimens taken during one week in 1984, it is unknown from any other collections. A second winged species was taken in much smaller numbers at the same time. That other species, H. lepidostylus , is easily distinguished by the abdominal characters given in the key but is externally identical to H. oliveri . Females of these two species were associated by relative abundance (the rare females were assumed to be associated with the rare male and were both treated as H. lepidostylus ). No females were treated as type specimens.

Figures

FIGURES 1 – 8. Howickia trilineata group, plate 1. Howickia bicolor Marshall, sp. n.: 1, habitus. Howickia oliveri Marshall, sp. n.: 2, habitus; 3, head; 4, right wing. Howickia mercurialis Marshall, sp. n.: 5, habitus; 6, left wing. Howickia omamari Marshall, sp. n.: 7, head; 8, habitus.

FIGURES 46 – 48. Howickia oliveri Marshall, sp. n.: 46, epandrium, sternite 8, synsternite 6 + 7, and sternite 5, left lateral; 47, aedeagus and associated structures; 48, female terminalia, dorsal.