Howickia sabina (Richards) 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 : 101-103

Howickia sabina (Richards) comb. nov.

( Figs. 28.1–28.6 )

Otwayia sabina Richards, 1973: 390 ; Marshall, 1989: 605; Roháček et al., 2001: 183.

Description. Body length: 1.3–1.7 mm, males smaller than females (as stated by Richards, 1973).

Head: Orange-brown, lower third of frons orange; ocellar triangle, frontal vitta (narrowly), interfrontal plates and orbital plates with pale yellow microtomentose stripes; lunule with silvery microtrichia; face with two patches of silvery microtomentum; gena yellow-brown with diagonal silvery microtomentose stripe; antenna orange. Frontal width 1.4x interfrontal height. Three pairs of interfrontal bristles, middle pair largest with tips crossing; 1 lateroclinate orbital bristle. Ocelli absent. Gena with strong upcurved bristle and 3–4 finer seta, finely rugose, shiny, lower third microtrichose; vibrissal angle with 1 smaller seta. Face normal; palpus clavate with 1 large apical seta. Eye height 3.2x genal height.

Thorax: Dark brown, lateral edges lighter; scutum shiny despite grey microtrichia; katatergite black. One pair of dorsocentral bristles; 6–7 rows of short, relatively stout acrostichal setulae. Prosternum broad, anteriorly truncate. Scutellum shiny but heavily microtrichose, semicircular, its length 0.3x its width; 4 scutellar bristles long, basal pair 1.3x length of apical pair.

Legs: Yellow-brown, fore and mid tibiae dark brown, hind tibia yellow-brown; tarsi brown, fore tarsi paler. 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: Highly reduced, no identifiable veins, extending to end of scutellum. Halter absent.

Male abdomen: Black, shiny, postabdomen paler. T2–5 and S2–4 heavily sclerotized, uniformly long-setose with large posterolateral setae, setae dark brown. S5 broad but short (width 3.0x length), asymmetrical (right side 1.3x longer than left), rather sparsely long-setose, broadly posteromedially desclerotized with many short, stout setae throughout and a posteromedial row of 19–20 stout, flattened teeth. Epandrium large, hemispherical, and sparsely long-setose; cercus slightly protruding, subrectangular with several moderate setae. Hypandrium medially tapered, sinuate; ventral lobe stout, triangular and curved forwards slightly; posterodorsal lobe elongate, originating from the posterior edge of the medial part. Surstylus subrectangular with a lateral patch of long setae, an outer brush of 4–5 enlarged apical setae and an inner pair of stout apical thorn-like setae. Postgonite elongate, gently tapered, and angled forwards about midlength, apical half with several setulae along anterior edge. Phallapodeme elongate, slightly sinuate with a moderate dorsal fin along anterior half; basiphallus elongate, arms tapered and gently curved apically. Distiphallus divided into two distinct sections: basal half with a large, saddle-like dorsal sclerite connected to an elongate, ventral sclerite which broadens and curls upwards apically to fit into distal half; distal half with a small, triangular dorsal sclerite and a large, shoe-like ventral lobe supporting a membranous apex.

Female abdomen: Black, sternites shinier than tergites, S6–7 covered in silver-greyish microtrichia (according to Richards). Cercus very small, pale with small setulae.

Type material. Holotype: AUSTRALIA: Victoria: Otway Ranges, Grey River crossing, 26.i.1967, G. Monteith, T.7129 (♂, QMBA).

Paratypes: AUSTRALIA: Victoria: Otway Ranges, Mount Sabine , 26.i.1967, G. Monteith (2 ♂, 1 ♀, UQIC & BMNH); same data as holotype (5 ♂, 4 ♀, QMBA). Types in UQIC now stored at the QMBA.

Material examined. Paratypes: AUSTRALIA: Victoria: Otway Ranges, Grey River crossing, 26.i.1967, G. Monteith (2 ♂, QMBA) .

Comments. Only male specimens were examined during this study, so the redescription of female terminalia is based on Richards (1973). Richards (1973) justified Otwayia as a separate genus by its lack of ocelli, lack of halters, broader wing stub (which he compared to the South American Archiborborine genus Penola Richards, 1941 ) and broad scutellum (compared to the South American Archiborborine genus Frutillaria Richards, 1961 ) because this combination of characters separated it from other brachypterous genera recognized in his 1956 key to flightless genera. He referred to the genitalia as “somewhat like those of Leptocera (Biroina) ”, a point that we confirmed by examining Richards’ holotype dissections of O. sabina . Otwayia sabina has the tripartite hypandrium that defines Howickia and it was recovered deep within Howickia in our phylogenetic analysis ( Fig. 2.2 ). Otwayia is therefore treated as a synonym of Howickia .

Figures

FIGURES 2.1. Phylogeny of Australian species of Howickia Richards based on the morphological character states in Table 1 and the associated character list, including all characters associated with wing loss. The cladogram was rooted by Paralimosina Papp + Eximilimosina Papp as the outgroup. Solid circles indicate unique synapomorphies, empty circles indicate homoplasies, and crossed circles indicate reversals. Numbers above circles indicate the character number, numbers below the circles indicate multistate character states (unordered). Species names highlighted in blue indicate apterous species and names highlighted in green indicate brachypterous species. Tree branches highlighted in red indicate tentative species placements due to weak morphological support.

FIGURES 28.1–28.6. Howickia sabina (Richards). 28.1, male habitus, lateral; 28.2, male head, anterolateral; 29.3, right wing; 28.4, male S5–8, ventral; 28.5, male terminalia, lateral; 28.6, aedeagus and associated structures, lateral. Body and head scale bars indicate 0.5 mm, wing scale bar indicates 0.2 mm.