Howickia irwini, Kuwahara & Marshall, 2022

Kuwahara, Gregory K. & Marshall, Stephen A., 2022, A revision of the Australian species of Howickia Richards (Diptera: Sphaeroceridae: Limosininae), Zootaxa 5192 (1), pp. 1-152 : 125

Howickia irwini sp. nov.

( Figs. 38.1–38.8 )

Description. Body length: Males 1.7–1.9 mm, females 1.8–2.3 mm.

Head: Caramel-brown; frontal vitta, interfrontal plates, and orbital plates with yellowish microtomentose stripes, extending laterally at level of ocellar triangle to almost touch and create an M-shaped mark; gena pale yellow, often translucent; antenna yellow. Frontal width 1.3x interfrontal height, frontal vitta narrow. Two pairs of fine, moderate interfrontal bristles preceded by a smaller pair (0.5x length of posterior pairs); 2 lateroclinate orbital bristles, anterior bristle 0.4x posterior bristle. Gena with strong but fine upcurved bristle and 1–2 smaller setae, finely rugose and microtrichose along ventral quarter; vibrissal angle with 1 smaller setae. Face shiny with ventromedial margin slightly flattened; palpus clavate with 1 large apical and 1 large preapical setae. Eye height 2.7x genal height.

Thorax: Dark reddish-brown; scutum shiny despite brown microtrichia, lateral edges broadly reddish; katatergite black. One pair of dorsocentral bristles; 6–7 rows of long, fine acrostichal setulae. Prosternum broad, anteriorly rounded. Scutellum heavily microtrichose, reddish, semicircular, its length 0.4x its width; 4 scutellar bristles long, basal pair 1.5x length of apical pair.

Legs: Brown, mid and hind femora distally and tibiae proximally and distally yellow; fore tarsi white, other tarsi golden-brown. Male mid tibia with a large apicoventral bristle. Basal half of mid tibia with 2 dorsal bristles (1 anterodorsal and 1 posterodorsal), distal half with 2 dorsal bristles (1 anterodorsal and 1 posterodorsal).

Wing/halter: Halter absent.

Male abdomen: Black, heavily sclerotized, shiny, postabdomen reddish. T2–5 and S2–4 broad, uniformly longsetose along entire surface. S5 broad but short (width 4.0x length), asymmetrical (left side longer and narrower than right), sparsely long-setose with a slightly deflexed, rectangular posteromedial lobe bearing a posterior row of 14 short, flat teeth with posterior corners tipped with small knobs bearing tufts of setulae. Epandrium small, flattened, densely long-setose along posterior face (bare anterolateral corners); cercus white, flattened and ventromesially cleft, resembling a horse head (combined cerci M-shaped) with a single sinuate medial seta. Hypandrium medially sinuate, rather short; ventral lobe absent; posterodorsal lobe elongate and strongly bisinuate. Surstylus bilobed: anteroventral lobe large, broad, subrectangular with a row of lateral setae; posterior lobe thin, curved and originating from posterodorsal edge of anterior lobe, apically with a large blade-like seta and inner edge with another strong blade-like seta. Postgonite rather simple, elongate, rectangular, and slightly sinuate. Phallapodeme slightly sinuate, apex gently broadened; basiphallus with triangular arms, anterior edges sinuate. Distiphallus simple, strongly sinuate, tubular in basal half, largely desclerotized, especially so apically, apex membranous and scoop-like.

Female abdomen: Black, heavily sclerotized, shiny despite some microtrichia. T2–5 and S2–5 uniformly long-setose along entire surface. Preabdomen subequal in length to head + thorax. Postabdomen short, stout, 3.1x length of T5. T6 and T7 reduced to short, lateral L-shaped plates which may be joined posteriorly, each bearing 3 apical setae. Epiproct pentagonal and dorsomedially bearing a pair of setae. Cercus short, subtriangular, apically diverging with 3 long sinuate setae (1 lateral, 1 apical and 1 dorsal) and several smaller setulae. S6 and S7 small but relatively well-developed, present as microtrichose, rectangular plates bearing a posterior row of 6 setae. S8 reduced to a broad, ovoid, microtrichose plate bearing a posterior row of 4 setae. Hypoproct broad, rounded, posteriorly microtrichose with a row of setae. Spermathecae stout, egg-shaped and deeply grooved; stem short (0.3–0.5x length of spermatheca) and cylindrical.

Material examined. Holotype: AUSTRALIA: New South Wales: Kyogle , 1000 m, Nothofagus forest, 9.vii.1980, S. & J. Peck (♂, AMSA).

Paratypes: AUSTRALIA: New South Wales: 32 km NE Wiangaree, Wiangaree State Forest , 1000 m, Nothofagus litter, 24.viii.1982, S. & J. Peck (2 ♂, 1 ♀, AMSA, DEBU) ; 33 km NE Wiangaree, near Tweed Valley Lookout, rainforest, flight-intercept trap, 13.vi–24.viii.1982, S. & J, Peck (1 ♂, DEBU) ; Gibraltar Range , 29˚31’S 152˚22’E, 950 m, volcanic, pitfall trap, 23.ix.1999, J. Holt (2 ♂, 2 ♀, AMSA, DEBU) ; same data as holotype (14 ♂, 22 ♀, AMSA, DEBU) .

Etymology. This name is in honour of the late Steve Irwin, whose passion for wildlife and conservation in Australia and around the world helped spark the first author’s interest in nature, wildlife, and biodiversity.

Comments. Howickia irwini externally resembles H. sabina and the yellow-headed, black-bodied morph of H. regalis , which also have a frons with golden stripes. Howickia irwini can be distinguished from H. sabina by the complete absence of wings and the dark legs with apically pale femora, and from H. regalis by the two pairs of orbital setae and the white fore tarsi.

Figures

FIGURES 38.1–38.5. Howickia irwini sp. nov. 38.1, male habitus, lateral; 38.2, male head, anterolateral; 38.3, male S5–8, ventral; 38.4, male terminalia, lateral; 38.4a, left surstylus, posterior; 38.5, aedeagus and associated structures, lateral. Scale bars indicate 0.5 mm.