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

description: Howickia flaviterga (Richards) comb. nov.
(Figs. 3.6, 9.1–9.9)
Leptocera (Acuminiseta) flaviterga Richards, 1973: 362.
Acuminiseta flaviterga (Richards), Marshall, 1989: 602; Roháček et al., 2001: 111.
Australimosina flaviterga (Richards), Papp, 2008: 134.
Description. Body length: Males 2.0–3.0 mm, females 2.4–3.7 mm.
Head: Dark brown, lower quarter of frons orange; frontal vitta and orbital plates reddish; interfrontal plates and orbital plates with pale microtrichia; gena slightly reddish; antenna brown. Frontal width 1.8x interfrontal height. 2–3 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 3–4 smaller setae, finely striate, densely microtrichose; vibrissal angle with 2 subvibrissal setae. Face normal; palpus clavate with 2 large apical setae. Eye height 3.2x genal height.
Thorax: Dark brown; scutum shiny despite brown microtrichia, posterolateral edges lighter and with pale spots on posterior notopleural lobe; anepimeron with lighter posteroventral spot.Two pairs of dorsocentral bristles (anterior pair 0.6x length of posterior); 7–8 rows of long, fine acrostichal setulae. Prosternum narrow, linear, posteriorly expanded. Scutellum microtrichose, semicircular, its length 0.7x its width; 4 scutellar bristles long, apical pair 1.5x length of basal pair.
Legs: Brown, tibiae proximally paler; tarsi brown. Male mid tibia with a stout apicoventral bristle and 2 rows of stout ventral setae, mid femur with 2 corresponding rows of strong proximoventral setae. Basal half of mid tibia with 3 dorsal bristles (2 anterodorsal and 1 posterodorsal), distal half with 3 dorsal bristles (2 anterodorsal and 1 posterodorsal).
Wing/halter: Moderately infuscate. CS2 subequal to CS3. R 2+3 sinuate, distal curve stronger than basal curve; R 4+5 upcurved, meeting costa well before wing tip; costa extending past R 4+5 (5x costal width). Halter pure white.
Male abdomen: Brown, shiny. T2–3 and S2–3 largely desclerotized, T4–5 and S4 desclerotized around edges, shiny, medially normally sclerotized, uniformly long-setose along posterior half. S5 large, shiny, posteromedially desclerotized and bulging with dense patch of short setae, laterally with much longer setae. Epandrium large, spherical, and uniformly long-setose; cercus flattened, rectangular with 3 very long setae and numerous smaller setae. Hypandrium medially strongly sinuate; ventral lobe broad, triangular, and extending from main part at a 60˚ angle; posterodorsal lobe short. Surstylus subtriangular with an anteroventral row of small setulae, apically with a large (0.8x surstylar length) thorn-like seta and several smaller lateral setae. Postgonite elongate, sinuate, proximally with a pair of anterior setulae, distal third with numerous minute anterior setulae, apex curved forwards smoothly. Phallapodeme sinuate with constriction along apical eighth and large dorsal fin; basiphallus short, rectangular. 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 V-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, T2–5 usually desclerotized around edges, shiny despite central patch of microtrichia. T2–5 sparsely 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 sparse setal bands. Preabdomen slightly shorter than length of head + thorax. Postabdomen elongate, 3.0x length of T5. T6 and T7 reduced to a pair of L-shaped lateral plates, each bearing a posterior row of 3 setae. Epiproct pentagonal with a short posteromedial split and dorsomedially bearing a pair of setae. Cercus subtriangular with 5 long sinuate setae (1 apical, 2 lateral and 2 dorsal) and several smaller setulae. S6 and S7 reduced to “hollow” bell-shaped plates bearing a posterior row of 8–9 setae. S8 present as an ovoid, entirely microtrichose plate with a preapical pair of setae. Hypoproct hexagonal, acornshaped, posteriorly microtrichose with a preapical patch of setae. Spermathecae stout, conical and strongly grooved; stem subequal in length to spermatheca, tapered and bearing rows of spicules.
Type material. Holotype: AUSTRALIA: Australian Capital Territory: Mount Gingera, 28.i.1952, K.R. Norris (♂, ANIC). Examined by Marshall in 1999.
Paratypes: AUSTRALIA: Australian Capital Territory: same data as holotype (2 ♂, 2 ♀); New South Wales: 12 miles south of Deloraine, 220 ft., 5.iii.1963, I.F.B. Common (1 ♀); Fitzroy Falls, 3.x.1938, A.L. Tonnoir (1 ♀); Mount Wilson, 3.vii.1961, D.H. Colless (1 ♀); all in ANIC except 1 ♂ and 1 ♀ in BMNH. Paratype photos provided by James Lumbers, ANIC.
Material examined. AUSTRALIA: New South Wales: Mount Wilson, 33˚18’36”S 150˚13’12”E, pans, 17– 21.iii.1999, S.A. Marshall (4 ♂, DEBU); Tasmania: Chauncy Vale, 4 km E Bagdad, creek bed, pans, 9–10.xii.2003, S.A. Marshall (3 ♂, 1 ♀, DEBU); Cradle Mountain National Park, Dove Lake, 920 m, dung pans in button grass, 16–17.xii.2003, S.A. Marshall (1 ♂, DEBU); Cuckoo Falls, 4 km E Scottsdale, along Falls Road, along creek, pans/some dung, 14.xii.2003, S.A. Marshall (3 ♂, 1 ♀, DEBU); Mount Williams, Stumpy Bay, dry heath, pans, 12– 13.xii.2003, S.A. Marshall (1 ♂, DEBU); Tasmanian Wilderness World Heritage Forest, 43˚05’42”S 146˚39’14”E, 112 m, forest, Malaise trap, 9.ix.2014, T. Wardlaw (1 ♀, BIOUG); Waratah, 8 km SW, 41˚29’04”S 145˚27’41”E, rainforest, pans, 20–21.xii.2003, S.A. Marshall (2 ♂, 2 ♂, DEBU); Victoria: Acheron Gap, 16 km N Warburton, 750 m, Nothofagus grove, carrion, 28.iv–7.v.1978, S. & J. Peck (3 ♂, DEBU); Tarra–Bulga National Park, 450 m, Nothofagus ravine, carrion trap, 10–17.v.1978, S. & J. Peck (15 ♂, 7 ♀, DEBU); Wilson Promontory National Park, Lilly Pilly trail, 3 m, carrion pitfall trap, 12–16.v.1978, S. & J. Peck (2 ♂, DEBU); Wilson Promontory National Park, Lilly Pilly trail, carrion pitfall trap, 12–16.v.1978, S. & J. Peck (3 ♂, 1 ♀, DEBU).
Comments. Acuminiseta was erected as a subgenus of Leptocera Olivier, based on the species Limosina pallidicornis Villeneuve from Africa (Congo); in this same paper, Duda (1925) described 5 other species of Acuminiseta from around the world. Vanschuytbroeck (1950) described one more species of African Acuminiseta and Richards (1973) described two Australian species. In his original description, Richards (1973) stated that his type specimens for Acuminiseta flaviterga varied in external characters, and may have even belonged to multiple species, noting that A. flaviterga “does not run down very well to the subgenus Acuminiseta but seems better placed there than in Limosina ” (sensu Richards). The poorly supported placement of two Australian species in an otherwise African genus cast doubt on the monophyly of Acuminiseta. In their world catalog of Sphaeroceridae, Roháček et al. (2001) noted that the genus at that point was certainly paraphyletic and in major need of revision, with Richards’ species in particular having uncertain generic placement.
Papp (2008) briefly reviewed all known Old World genera of sphaerocerids, and in doing so moved most of the species of Acuminiseta into two new genera (Australimosina & Eximilimosina) and one previously named genus (Spinilimosina Roháček, 1983), leaving only the type species and one very similar new species in Acuminiseta and ignoring the other four species described in Acuminiseta (A. cercalis Richards, 1973, A. flavicornis Duda, 1925, A. longiventris Duda, 1925, and A. rugarii Vanschuytbroeck, 1950). However, Papp (2008) never commented on why or how he separated A. flaviterga (the type of his new genus Australimosina) from the other species, why he erected the genus Australimosina as different from Acuminiseta or why A. cercalis (the other Australian species placed in Acuminiseta by Richards) was not considered. The true generic placement of A. cercalis is uncertain, though it is certainly not a species of Howickia, unlike H. flaviterga. Notes made from the type specimen from Otford, NSW, in the Australian National Insect Collection in 1999 indicate an unusual mid tibial dorsal chaetotaxy (paired proximal bristles but two unpaired distal bristles) and patterned wings (three pale bands on a dark background) which set it apart from Howickia.
Howickia flaviterga has the standard mid tibial chaetotaxy of winged Howickia (paired bristles at one-third and four-fifths with an additional seta just proximal to the lower pair), a sinuate R 2+3, the male S5 with a posteromedial patch of stout setae present in several species of Howickia, relatively short surstyli and (most importantly) the tripartite hypandrium that defines Howickia. Australimosina is therefore a junior synonym of Howickia. The holotype of H. flaviterga (examined by Marshall in 1999) has stronger pigment lines along the wing veins than the paratypes, suggesting that Richards illustrated and described one of the paratypes rather than the holotype. Papp based his concept of Australimosina on Richards’ (1973) description, without first-hand examination of the holotype. Our concept of Howickia flaviterga is also based on Richards’ paratype description supplemented by photos of the type material and matches Papp’s illustrations of “ Australimosina ” flaviterga, but we have not examined the male holotype in the current study. Until the holotype male is dissected, the possibility will remain that there are two species under this name, and that the species treated here as “ flaviterga ” will require a new name.
Howickia flaviterga is part of the H. flaviterga species group, which also includes H. acicula, H. biantenna, H. grandisterna, and H. percostata. Howickia flaviterga differs from H. acicula and H. grandisterna in having eight rows of acrostichal setulae, from H. biantenna in having three interfrontal bristles and slightly shorter scutellum, and from H. percostata in having three dorsal bristles in the proximal half of the mid tibia. Male genitalia also differ significantly.
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 38-42, DOI: 10.11646/zootaxa.5192.1.1, http://zenodo.org/record/7138639