Howickia cruspica, 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 : 95-98

Howickia cruspica sp. nov.

( Figs. 26.1–26.5 )

Description. Body length: Female 1.8 mm.

Head: Yellow, areas between frontal vitta and orbital plates orange-yellow; frontal vitta striate and shiny, orbital plates microtrichose; gena yellow; antenna yellow, apically pale. Frontal width 1.5x interfrontal height, frontal vitta narrow. Two pairs of large interfrontal bristles preceded by a smaller pair (0.6x length of posterior pairs); 2 lateroclinate orbital bristles, anterior bristle 0.6x length of posterior bristle. Gena with large upcurved bristle and 2 smaller setae, finely and densely striate, shiny, lower third microtrichose; vibrissal angle with 2 very fine subvibrissal setae. Face shiny with a very small flattened triangle along ventral margin; palpus clavate with 1 large apical and 1 large preapical seta. Eye height 2.0x genal height.

Thorax: Dark brown; scutum shiny despite microtrichia, posterolateral corners yellow-brown and with pale spot on posterior notopleural lobe; posterodorsal corners of anepisternum and katepisternum lighter brown, katatergite black. Two pairs of dorsocentral bristles (anterior pair 0.6x length of posterior pair); 6–7 rows of long, fine acrostichal setulae. Prosternum narrow, linear, posteriorly expanded. Scutellum microtrichose, subquadrate, its length 0.5x its width; 4 scutellar bristles long, apical pair 1.5x length of basal pair.

Legs: Brown, fore and mid femora caramel-brown and distally paler, hind femur dark brown, tibiae paler than femora; tarsi dirty-white. Mid basitarsus with a distinctly enlarged ventral seta; hind femur with a large curved apicoventral spur. Basal half of mid tibia with 5 dorsal bristles (3 anterodorsal and 2 posterodorsal), distal half with 3 dorsal bristles (2 anterodorsal and 1 posterodorsal).

Wing/halter: Wings significantly reduced, extending to about midpoint of T4; veins reduced but all identifiable: CS2 0.5x length of CS3; R 2+3 sinuate, meeting costa above crossvein i-m; R 4+5 strongly upcurved, meeting costa well before wing tip; costa slightly overpassing R 4+5. Halter slightly reduced and pure white.

Male abdomen: Male unknown.

Female abdomen: Black, shiny despite dense microtrichia. T2–5 and S2–5 heavily sclerotized, sparsely longsetose; pleural membrane with sparse setae. Preabdomen slightly shorter than length of head + thorax. Postabdomen largely retracted into preabdomen, with only last few segments exposed, broad as far as can be seen and likely 3.0x length of T5. T6 and S6 hidden; T7 and S7 reduced to pairs of L-shaped plates, each bearing a posterior row of 2–3 setae. Medial plate of T8 appears to be absent or greatly reduced. Epiproct elongate, rhombic, centrally split into two equal lateral halves, each bearing a dorsal seta. Cercus elongate rectangular with 3–4 long sinuate setae (2 apical, 1 lateral and 1 dorsal) and several smaller setulae. S8 a broad, rectangular, posteriorly microtrichose plate with a posterior row of setae. Hypoproct broad but short, posteriorly microtrichose with a row of setae.

Material examined. Holotype: AUSTRALIA: Victoria: Warburton, Cement Creek , 200 m, 28.iv–7.v.1978, S. Peck (♀, ANIC).

Etymology. This species name refers to the enlarged apicoventral hind tibial spur (Latin ‘crus’: leg; Latin ‘spica’: spike, dart, spear).

Comments. Howickia cruspica is known from a single female specimen but is easily distinguishable from all other species of Howickia . This species was included in Howickia due to synapomorphies shared with known species of Howickia (mid tibia with paired proximal and distal dorsal bristles, sinuate R 2+3, curved R 4+5, telescopic female terminalia with reduced postabdominal sclerites). Without a male specimen of H. cruspica , it is impossible to determine whether this species has the defining hypandrial characters of Howickia , but the synapomorphies listed above provide some support for the placement of H. cruspica in this genus.

Howickia cruspica has the largest wing of the three brachypterous species of Howickia , and is the only species of Howickia to have an enlarged apicoventral spur on the hind tibia. The only other brachypterous species known from VIC, Howickia sabina ( Richards, 1973) , has a striped frons, a shorter gena, smaller wings, no apicoventral spur on the hind tibia, and only two dorsal setae on the basal half of the mid tibia.

Figures

FIGURES 26.1–26.2. Howickia cruspica sp. nov. 26.1, female habitus, lateral; 26.2, female head, anterolateral. Scale bars indicate 0.5 mm.