Howickia tricolor, 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 : 142-144

Howickia tricolor sp. nov.

( Figs. 44.1–44.8 )

Description. Body length: Males 1.2–2.0 mm, females 1.3–2.4 mm.

Head: Reddish-brown, darkest behind level of ocelli; frontal vitta rugose and broad; gena reddish-brown; antennae yellow. Frontal width 1.6x interfrontal height. Two pairs of strong interfrontal bristles, preceded by a slightly smaller pair (0.6–0.7x length of posterior pairs); 1 lateroclinate orbital bristle, preceded by a minute setula. Ocelli present but small. Gena with 2–3 fine setae, very finely rugose, shiny, lower quarter microtrichose; vibrissal angle with 1 smaller seta. Face bulging and evenly convex, somewhat continuous with lunule; palpus clavate with 2 large preapical setae. Eye height 3.0x genal height.

Thorax: Pale orange; scutum shiny despite dense microtrichia, lateral edges yellow; katatergite shining black. One pair of dorsocentral bristles; 7–8 rows of short, fine acrostichal setae. Prosternum narrow, linear, posteriorly expanded. Scutellum rugose, semicircular, its length ~0.4x its width; 4 scutellar bristles long, basal pair 1.8x length of apical pair.

Legs: Yellow; tarsi pale yellow, apical 4 tarsomeres of fore leg white. Male mid tibia with a large apicoventral bristle. Basal half of mid tibia with 3 dorsal setae (2 anterodorsal and 1 posterodorsal), distal half with 3 dorsal setae (2 anterodorsal and 1 posterodorsal).

Wing/halter: Halter absent.

Male abdomen: Black, heavily sclerotized, shiny, postabdomen reddish. T2–5 and S2–4 uniformly long-setose along entire surface. S5 broad but short (width 4.0x medial length), asymmetrical (right side 1.7x longer than left), sparsely long-setose, broadly posteromedially emarginate with a posterior row of thickened setae, shortest medially and longest laterally. Epandrium moderate, uniformly long-setose; cercus flat, somewhat bulging ventrolaterally, and with numerous long setae. Hypandrium medially sinuate; ventral lobe small, medially sclerotized and broadly membranous laterally; posterodorsal lobe long but thin, largely membranous. Surstylus bilobed, anterior lobe small and rounded, posterior lobe larger, triangular, slightly twisted and folded inwards with a very thick, curved, apicoventral thorn-like seta and many fine, posterior setulae. Postgonite very long, strongly sinuate, and gradually tapered. Phallapodeme slightly sinuate with a short dorsal ‘fin’ in the apical two-thirds; basiphallus short, rounded posteriorly. Distiphallus short, stout, well-sclerotized with a small membranous apex.

Female abdomen: Black, heavily sclerotized, shiny despite dense microtrichia. T2–5 and S2–5 uniformly longsetose along entire surface. Preabdomen slightly longer than length of head + thorax. Postabdomen short, 2.0x length of T5. T6 well-developed and heavily sclerotized, densely microtrichose, and bearing a posterior row of setae; T7 well-developed and heavily sclerotized, shiny with only two lateral patches of microtrichia, with a small posteromedial emargination and only 4 posterior setae. Dorsal sclerite of T8 absent, lateral plates subquadrate. Epiproct small, shield-like, medially desclerotized and dorsomedially bearing a pair of setae. Cercus short, rounded with 4–5 long, sinuate setae (1 apical, 1–2 lateral, 1 dorsal, 1 preapical). S6 and S7 well-developed and heavily sclerotized, bearing a posterior row of setae. S8 elongate, U-shaped, anterior margin deeply emarginate, posterior third heavily microtrichose. Hypoproct small, shield-like, posteriorly microtrichose with a row of 4 stout setulae. Spermathecae stout, hemispherical and entirely lightly grooved; stem elongate (1.5–1.6x length of spermatheca), tapered and swollen basally.

Material examined. Holotype: AUSTRALIA: New South Wales: Lord Howe Island, Mount Gower track, Site G 26, 31˚34’58”S 159˚05’03”E, 660 m, Hedyscepe canterburyana forest, leaf litter, 21–31.iii.2005, N. Velez (♂, AMSA).

Paratypes: AUSTRALIA: New South Wales: Lord Howe Island, Mount Gower track, Site G27, 31°35’00”S 159°05’01”E, 690 m, Hedyscepe canterburyana forest, litter, 21–31.iii.2005, N. Velez (1 ♂, 1 ♀, AMSA); Lord Howe Island, Mount Gower track, Site G30, 31˚35’03”S 159˚04’57”E, 760 m, Zygogynum /Dracophyllum forest, leaf litter, 1–14.xi.2004, N. Velez (7 ♂, 13 ♀); Lord Howe Island, Mount Gower, bottom of southernmost gully, 31˚35’17”S 159˚04’23”E, 670 m, pitfall trap, 18–31.i.2002, I. Hutton (3 ♂, 5 ♀, AMSA); Lord Howe Island, Mount Lidgbird, west side of valley between Pimple and summit, 31°33’18”S 159°05’02”E, 650 m, Hedyscepe canterburyana , Macropiper hooglandii & Coprosma huttoniana leaf litter, 11.iv.2002, I. Hutton (3 ♂, 2 ♀, AMSA); Lord Howe Islands, Mount Gower, midway down ridge south of igloo, 31°35’10”S 159°04’30”E, 838 m, pitfall trap, 18–31.i.2002, I. Hutton (4 ♂, 17 ♀, AMSA); same data as holotype (2 ♂, 5 ♀, AMSA).

Other material examined: 233 additional specimens from Lord Howe Island, deposited in AMSA.

Etymology. This name refers to the three different colours of the body tagmata: the orange-brown head, the orange thorax, and the black abdomen (Latin ‘tricolor’: three-coloured).

Comments. The three species of Howickia found on Lord Howe Island are distinct and easily separated from one another. Howickia tricolor differs from H. nuda and H. robustaseta in the characteristic tricoloured body, having ocelli, large eyes, and a bulging face; no other species of Howickia has such a convex face.

Figures

FIGURES 44.1–44.5. Howickia tricolor sp. nov. 44.1, male habitus, lateral; 44.2, male head, anterior; 44.3, male S5–8, ventral; 44.4, male terminalia, lateral; 44.5, aedeagus and associated structures, lateral. Body scale bar indicates 0.5 mm, head scale bar indicates 0.25 mm.