Howickia percostata
Creators: name: Kuwahara, Gregory K.
name: Marshall, Stephen A.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Sphaeroceridae
Howickia
Howickia percostata

description: Howickia percostata (Richards)
(Figs. 3.13, 16.1–16.9)
Leptocera (Biroina) percostata Richards, 1973: 342.
Biroina percostata (Richards), Marshall, 1989: 602; Roháček et al., 2001: 126.
Howickia percostata (Richards), Marshall et al., 2014.
Description. Body length: Males 2.9–4.3 mm, females 2.4–4.3 mm.
Head: Dark brown, lower third of frons orange, frontal vitta orange, orbital plate lighter; frontal vitta, interfrontal plates and orbital plates with pale microtrichia; gena brown; antenna brown. Frontal width 2.0x interfrontal height. Two pairs of large interfrontal bristles preceded by a smaller pair 0.5x length of posterior pairs; 2 lateroclinate orbital bristles, anterior bristle 0.6x length of posterior bristle. Gena with strong upcurved bristle and 5–6 smaller setae, finely and densely striate, shiny, lower third microtrichose; vibrissal angle with 2–3 subvibrissal setae. Face with small flattened triangle along ventromedial margin; palpus triangular with 2 large apical setae. Eye height 2.1x genal height.
Thorax: Dark brown; scutum microtrichose but shiny, posterolateral edge lighter and with pale spot on posterior notopleural lobe; anepimeron with lighter posteroventral spot. Two pairs of dorsocentral bristles (anterior pair 0.5x length of posterior pair); 7–8 rows of long, fine acrostichal setulae. Prosternum narrow, linear, posteriorly expanded. Scutellum microtrichose, triangular, its length 0.7x its width; 4 scutellar bristles long, apical pair 2.0x length of basal pair.
Legs: Brown, tibiae slightly lighter than femora; tarsi beige. Male mid tibia with a stout apicoventral bristle and 2 short rows of stout ventral setae, mid femur with 2 corresponding rows of strong proximoventral setae. Basal half of mid tibia with 5 dorsal bristles (3 anterodorsal and 2 posterodorsal), distal half with 4 dorsal bristles (3 anterodorsal and 1 posterodorsal).
Wing/halter: Entirely infuscate. CS2 1.3x length of CS3. R 2+3 sinuate, distal curve stronger than basal curve, meeting costa at an angle of 70˚; R 4+5 upcurved, meeting costa well before wing tip; costa extending past R 4+5 (6x costal width). Halter pale; knob white; stem pale brown.
Male abdomen: Brown, shiny despite microtrichia. T2–3 and S2–3 largely desclerotized, T4 and S4 desclerotized around edges, medially normally sclerotized, uniformly long-setose along posterior half with large posterolateral setae. S5 large, shiny, densely setose, posteromedially desclerotized and bulging with patch of short setae, laterally with much longer setae. Epandrium large, flattened and uniformly long-setose; cercus slightly expanded, subtriangular with 1 very long sinuate seta and numerous smaller setae. Hypandrium medially strongly upcurved; ventral lobe narrow, triangular, and extending from main part at an 80˚ angle; posterodorsal lobe strongly curved down posteriorly and originating form the posterior edge of the medial part, apex flattened and diamond-shaped. Surstylus bean-shaped with an anteroventral row of small setulae, apically with a large thorn-like seta and several fine lateral setae. Postgonite very elongate, proximally with a pair of anterior setulae, distal third tapered with numerous minute anterior setulae, apex curved forwards smoothly. Phallapodeme sinuate with small dorsal fin along anterior third; basiphallus short, slightly sinuate. Distiphallus divided into two distinct sections: basal half heavily sclerotized with a large saddle-like dorsal sclerite and a flattened ventral sclerite articulating to form a tube; distal half with a Y-shaped dorsal sclerite and a thin ventral sclerite fused laterally into a tube supporting a membranous apex with numerous dorsoapical rows of small spicules.
Female abdomen: Brown, T2–4 often desclerotized along edges (especially anterior), heavily microtrichose. T2–5 uniformly long-setose in posterior two-thirds with large posterolateral setae, S2–5 uniformly long-setose along entire surface with large posterolateral setae; pleural membrane with setal patches. Preabdomen subequal to length of head + thorax. Postabdomen elongate, narrow, 3.1x length of T5. T6 relatively well-developed, present as a microtrichose, “hollow” rectangular plate and bearing a posterior row of 8 setae; T7 reduced to a microtrichose, “hollow” bell-shaped plate bearing a posterior row of 6 setae. Epiproct subrectangular and bearing a pair of dorsomedial setae. Cercus subtriangular with 4 long sinuate setae (1 apical, 2 lateral and 1 dorsal) and several smaller setulae. S6 and S7 relatively well-developed, present as microtrichose, rectangular plates with some central desclerotization and bearing a posterior row of 8–10 setae. S8 an ovoid, entirely microtrichose plate with a patch of setae. Hypoproct rounded, microtrichose with a patch of larger setae. Spermathecae stout, spherical, deeply grooved with a deep apical invagination; stem elongate (3.0x length of spermatheca), tapered and smooth.
Type material. Holotype: AUSTRALIA: New South Wales: Monga, 19.vii.1962, D.H. Colless (♂, ANIC). Holotype photos provided by James Lumbers, ANIC.
Paratypes: AUSTRALIA: New South Wales: Brown Mountain, Bega district, 8.iii.1963, D.H. Colless (1 ♀, ANIC); Clyde Mountain, near Braidwood, 730 m, 25.ii.1961, D.K. McAlpine (1 ♀, AMSA); same data as holotype (1 ♀, ANIC).
Material examined. AUSTRALIA: New South Wales: Bruxner Park, N of Coffs Harbour, 200 m, rainforest, 9–13.vii.1978, S. & J. Peck (1 ♂ DEBU); Queensland: Mount Carbine, dry gum forest, dung, 12.iv.1999, S.A. Marshall (1 ♀, DEBU); Tasmania: Waratah, 8 km SW, 41˚29’04”S 145˚27’41”E, rainforest, dung pans, 20– 21.xii.2003, S.A. Marshall (2 ♂, DEBU); Victoria: Acheron Gap, 16 km N Warburton, 750 m, Nothofagus grove, carrion, 28.iv–7.v.1978, S. & J. Peck (1 ♂, DEBU); Bright Mountain Buffalo National Park, carrion trap, 22– 27.iv.1978, S. & J. Peck (1 ♂, DEBU); Mount Donna Buang, 1200 m, 28.iv–7.v.1978, S. & J. Peck (14 ♂, 15 ♀, DEBU); Tarra–Bulga National Park, 450 m, Nothofagus ravine, carrion trap, 10–17.v.1978, S. & J. Peck (18 ♂, 17 ♀, DEBU); Wilsons Promontory National Park, Lilly Pilly trail, 3 m, carrion pitfall trap, 12–16.v.1978, S. & J. Peck (5 ♀, DEBU).
Comments. Howickia percostata is part of the H. flaviterga species group, which also includes H. acicula, H. biantenna, H. flaviterga, and H. grandisterna. It can be differentiated from these other species by the presence of four dorsal bristles in the proximal half of the mid tibia. Male genitalia also differ significantly. Howickia percostata is also externally similar to the sympatric H. hardyina, with both species recorded from similar localities in NSW and VIC. Howickia percostata differs from H. hardyina in having two pairs of dorsocentral bristles, four pairs of interfrontal setae, and unique male and female terminalia.
description: Published as part of Kuwahara, Gregory K. & Marshall, Stephen A., 2022, A revision of the Australian species of Howickia Richards (Diptera: Sphaeroceridae: Limosininae), pp. 1-152 in Zootaxa 5192 (1) on pages 63-64, DOI: 10.11646/zootaxa.5192.1.1, http://zenodo.org/record/7138639