Howickia dealata (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 : 111-113

Howickia dealata (Richards) comb. nov.

( Figs. 32.1–32.5 )

Monteithiana dealata Richards, 1973: 393 ; Marshall, 1989: 604; Roháček et al., 2001: 172.

Description. Body length: 1.6–1.7 mm, males smaller than females (as stated by Richards, 1973).

Head: Golden-yellow, upper half of frontal vitta, orbital plates and behind dark brown, lower half of frontal vitta pale yellow; orbital plates and ocellar triangle microtrichose; gena brownish-yellow; antenna yellow, apically darkened. Frontal width 1.4x interfrontal height, frontal vitta narrow. Two pairs of large interfrontal bristles preceded by a smaller pair of setae; 2 lateroclinate orbital bristles, anterior bristle 0.7x length of posterior bristle. Gena with strong but fine upcurved bristle and 4–5 fine upcurved setae, finely striate, shiny, lower third microtrichose; vibrissal angle with 1 subvibrissal seta. Palpus clavate with 2 large apical setae. Eye height 3.2x genal height.

Thorax: Black; scutum shiny despite fine brown microtrichia, posterior edge slightly reddish. One pair of dorsocentral bristles; 7–8 rows of short, stout acrostichal setulae. Prosternum broad, anteriorly acute. Scutellum shiny but heavily microtrichose, black, semicircular, its length 0.3x its width; 4 scutellar bristles long, basal pair 1.3x length of apical pair.

Legs: Dark brown, femora proximally and tibiae proximally and distally lighter; tarsi yellow-brown. Male mid tibia with a moderate 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: Halter absent.

Male abdomen: Black, heavily sclerotized, shiny, postabdomen slightly paler. T2–5 and S2–4 uniformly longsetose along entire surface. S5 broad but short, densely setose with posteromedial margin broadly desclerotized and bearing a row of 6 short, flattened teeth. Epandrium large, hemispherical, and densely long-setose; cercus semicircular with a large sinuate seta and several smaller setae. Hypandrium medially strongly curved; ventral and posterodorsal lobes present but undescribed (see comments). Surstylus subtriangular with dense setation along posterior surface and a stout apicoventral thorn-like seta. Postgonite elongate, tapered and slightly curved. Phallapodeme slightly curved. Distiphallus apparently largely membranous with two lateral, well-sclerotized plates.

Female abdomen: Black, heavily sclerotized, shiny despite microtrichia. T2–5 and S2–5 wide, uniformly long-setose along entire surface with large posterolateral setae; pleural membrane bare. Preabdomen subequal in length to head + thorax. Postabdomen retracted into preabdomen and hardened, making most of the postabdomen impossible to examine. Epiproct shield-like, medially split into 2 halves and dorsomedially bearing a pair of setae. Cercus short, subtriangular with 5 long sinuate setae (2 apical, 2 basolateral, 1 dorsal and 1 mesial) and several smaller setulae. S6 and S7 (as could be seen) relatively well-developed, present as broad, rectangular, microtrichose plates bearing a posterior row of setae. S8 elongate, ovoid with a preapical pair of setae surrounded by a patch of microtrichia. Hypoproct broad, shield-like, posteriorly microtrichose with a preapical row of setae. Spermathecae stout, cylindrical and strongly grooved; stem short (0.2x length of spermatheca) and connected to a bulbous basal expansion (appearing as a swollen disk with a sphere within the center); paired spermathecae both connected to the apical portion of the basal expansion.

Type material. Holotype: AUSTRALIA: Tasmania: Hellyer Gorge , 24.1 km N Waratah, 2–4.ii.1967, G. Monteith, T.7126 (♂, QMBA) . Holotype photos provided by Geoff Thompson, QMBA .

Paratypes: AUSTRALIA: same data as holotype (5 ♂, 6 ♀, UQIC & BMNH). Types in UQIC now stored at the QMBA.

Material examined. AUSTRALIA: Tasmania: Mount Field National Park, near Lake Fenton, 42˚41’S 146˚37’E, 1000 m, ANIC Berlesate No. 667, litter under Nothofagus gunnii & Athrotaxis selaginoides , 31.i.1980, Lawrence & Weir (1 ♀, DEBU).

Comments. The redescription of male terminalia is based largely on Richards’ (1973) description and illustrations. The only apparent male specimen (identified previously) available for this work was missing its abdomen, but a written description of the postabdomen by a previous student noted a clearly tripartite hypandrium but without further details. The only female specimen available for examination had its postabdomen retracted, making it impossible to evert the postabdomen without risking damaging or destroying the postabdomen, even after clearing, and so could not be illustrated. Some features were visible through the preabdominal sclerites and are described above.

One of two species originally described as Monteithiana , H. dealata , has mid tibial chaetotaxy similar to other wingless Howickia (paired bristles at one-third and four-fifths length), stout apical seta on the surstylus, male S5 with a posteromedial row of flattened teeth, and the tripartite hypandrium that defines Howickia . We here treat Monteithiana as a synonym of Howickia (see comments on H. cynthia (Richards)) .

Figures

FIGURES 32.1–32.5. Howickia dealata (Richards). 32.1, male habitus, lateral; 32.2, male head, anterior; 32.3, epiproct and cercus, dorsal; 32.4, S8 and hypoproct, ventral; 32.5, spermathecae. Body scale bar indicates 0.25 mm, head bar indicates 0.1 mm. Photo credit: G. Thompson.