Howickia biantenna, 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 : 27-30

Howickia biantenna sp. nov.

( Figs. 3.2 , 5.1–5.9 )

Description. Body length: Males 2.0– 2.5 mm, females 1.8–2.8 mm.

Head: Dark brown, lower quarter of frons orange (rarely without), frontal vitta reddish; frontal vitta, bases of interfrontal bristles and orbital plates with pale microtrichia; gena brown; antenna brown above and orange below. Frontal width 1.7x interfrontal height. Three 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 3 subvibrissal setae. Face with a slight triangular groove along ventromedial margin; palpus clavate with 2 large apical setae. Eye height 2.4x genal height.

Thorax: Brown; scutum shiny despite brown microtrichia, posterolateral edge lighter and with pale spots on posterior notopleural lobe; anepimeron with lighter posteroventral spot. One pair of dorsocentral bristles; 6–7 rows of long, fine acrostichal setulae. Prosternum narrow, linear, posteriorly expanded. Katepisternum with several small setulae in addition to large posterior seta. Scutellum microtrichose, subtriangular, its length 0.7x its width; 4 scutellar bristles long, apical pair 2.0x length of basal pair.

Legs: Brown, tibiae proximally slightly paler; tarsi pale 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: Lightly infuscate. CS2 slightly shorter than CS3. R 2+3 sinuate, distal curve slightly stronger than basal curve; R 4+5 rather strongly upcurved, meeting costa well before wing tip; costa extending far past R 4+5 (7x costal width). Halter pale; knob brown and apically white; stem pale brown.

Male abdomen: Brown, dull from dense microtrichia. T2–5 and S2–4 slightly desclerotized around edges, medially normally sclerotized, uniformly long-setose along posterior half with large posterolateral setae. S5 large, broad but short (width 3.5x length), desclerotized along right posterior edge with a posteromedial patch of short setae anterior to a row of 20 short, flat teeth, laterally with much longer setae. Epandrium large, spherical, and uniformly long-setose; cercus flattened, rectangular with 1 long, sinuate seta. Hypandrium medially gently sinuate; ventral lobe thin, triangular with knob at apex; posterodorsal lobe short. Surstylus rectangular, anteroventral corner thin and extending forwards slightly, posteroventral corner bulging outwards with two large, curved apical thornlike setae (outer one 1.5x length and 2.0x width of inner one) and two smaller lateral setae. Postgonite elongate, J-shaped, medial third bulging slightly, distal third curved forwards. Phallapodeme sinuate, apically broadened; basiphallus long, triangular with a slight anteromedial lobe. Distiphallus divided into two distinct sections: basal half heavily sclerotized with a large saddle-like dorsal sclerite and a slightly smaller saddle-like ventral sclerite articulating to form a tube; distal half with a V-shaped dorsal sclerite and a large saddle-like ventral sclerite fused laterally into a tube supporting a membranous apex with numerous dorsoapical rows of small spicules.

Female abdomen: Dark brown, T2–5 sometimes desclerotized along anterior edges, shiny despite microtrichia. 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 slightly shorter than length of head + thorax. Postabdomen elongate, narrow, 3.6x length of T5. T6 and T7 relatively welldeveloped, present as broad rectangular plates with some central desclerotization and bearing a posterior row of 8 setae. Epiproct rectangular with a triangular posteromedial point and dorsomedially bearing a pair of setae. Cercus semicircular with 4 long sinuate setae (1 apical, 2 preapical and 1 basolateral) and several smaller setulae. S6 and S7 relatively well-developed, present as largely microtrichose, rectangular plates with some central desclerotization and bearing a posterior row of 10 setae. S8 reduced to an ovoid, posteriorly microtrichose plate with 2 preapical pairs of setae. Hypoproct largely desclerotized, rounded, microtrichose with a preapical row of setae. Spermathecae elongate, clavate and entirely lightly grooved; stem very short (0.3x length of spermatheca) and strongly ridged.

Material examined. Holotype: AUSTRALIA: Tasmania: Mount Williams National Park, Stumpys Bay Campground, dry heath, pans, 12–13.xii.2003, S.A. Marshall, debu00247613 (♂, TMAG).

Paratypes: AUSTRALIA: same data as holotype (11 ♂, 22 ♀, TMAG, DEBU) .

Other material examined: AUSTRALIA: New South Wales: Minnamurra Falls , 4.x.1965, D.H. Colless (1 ♀, ANIC) . Tasmania: same data as holotype (6 ♂, 9 ♀, DEBU) ; near Weldborough , 41˚10’00”S 147˚08’00”E, Nothofagus forest, 20–25.ii.1993, J. Trueman et al., Site A (2 ♀, ANIC) ; Scottsdale , 20 km W, dry forest, dung pans, 14.xii.2003, S.A. Marshall (1 ♂, 3 ♀, DEBU) .

Etymology. This name is in reference to the two-toned antenna of the species (dark brown above and orange below).

Comments. Howickia biantenna is part of the H. flaviterga species group, which also includes H. acicula , H. flaviterga , H. grandisterna , and H. percostata . Howickia biantenna differs from H. acicula and H. grandisterna in having only one pair of dorsocentral bristles, from H. flaviterga in having four interfrontal bristles and a slightly longer scutellum, and from H. percostata in having three dorsal bristles in the proximal half of the mid tibia. Male genitalia also differ significantly. Howickia biantenna is sympatric with H. acicula and H. grandisterna , which were also collected at the same time in Mount Williams National Park.

Figures

FIGURES 3.1–3.22. Mid tibial chaetotaxy of macropterous Australian species of Howickia. 3.1, H. acicula sp. nov., a) dorsal, male, b) lateral male, c) lateral, female; 3.2, H. biantenna sp. nov., a) dorsal, male, b) lateral male, c) lateral, female; 3.3, H. brevior (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.4, H. capitalis (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.5, H. erythrocephala sp. nov., a) dorsal, male, b) lateral female; 3.6, H. flaviterga (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.7, H. fuscalis (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.8, H. grandisterna sp. nov., a) dorsal, male, b) lateral male, c) lateral, female; 3.9, H. hardyina (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.10, H. kurandensis (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.11, H. myrmecophila (Knab & Malloch), a) dorsal, male, b) lateral male, c) lateral, female; 3.12, H. nitidipleura (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.13, H. percostata (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.14, H. pertusa sp. nov., a) dorsal, male, b) lateral male, c) lateral, female; 3.15, H. pseudovittata sp. nov., a) dorsal, male, b) lateral male, c) lateral, female; 3.16, H. subsinuata (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.17, H. symmetrica (Richards), a) dorsal, male, b) lateral male; 3.18, H. trivittata (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.19, H. vernalis (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.20, H. wamini sp. nov., a) dorsal, male, b) lateral male, c) lateral, female; 3.21, H. wilsoni (Richards), a) dorsal, male, b) lateral male, c) lateral, female; 3.22, H. xanthocephala sp. nov., a) dorsal, male, b) lateral male, c) lateral, female. Scale bars indicate 0.25 mm.

FIGURES 5.1–5.5. Howickia biantenna sp. nov. 5.1, male habitus, lateral; 5.2, male head, anterolateral; 5.3, male S5–8, ventral; 5.4, male terminalia, lateral; 5.4a, left surstylus, posterior; 5.5, aedeagus and associated structures, lateral. Scale bars indicate 0.5 mm.