Lagenosoma dimorphum, Winterton, 2023

Winterton, Shaun L., 2023, Wasp-mimicking soldier flies of the Australian Region: revision of Ampsalis Walker, Elissoma White and Lagenosoma Brauer (Stratiomyidae: Clitellariinae), Zootaxa 5246 (1), pp. 1-63 : 34-36

Lagenosoma dimorphum sp. n.

( Figs 6 ; 15A–D ; 20 ; 21B ; 24B ; 26G–J ; 29G, H ; 33C, D ; 37 )

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Diagnosis. Antennae relatively elongate, flagellomere VIII plumose distally, flagellomeres IV–VII all short and approximately equal in length; male face bulbous yellow with erect black setae; female scutellum orange with black suffusion laterally; scutum orange (female) or black (male); male abdomen narrow, petiolate; male occiput entirely yellow.

Description. Body length = 8.0–9.0 mm. Head. Yellow, female varies from yellow with pair of black markings on frons ( Fig. 26H, J ) to entirely black ( Fig. 26I ); frons rounded; face broadly rounded and bulbous, yellow with pair of black markings below antennae, some erect, black setae, shorter in female; parafacial yellow (or black); ocellar tubercle black; postocular ridge highly carinate in female, not carinate in male; occiput flat, yellow, covered with black setal pile; antenna (length = 3.0 mm) with scape and pedicel dark yellow, flagellomeres I–III dark brown with dark microtrichia, flagellomeres IV–VIII black, flagellomeres V–VII relatively short and combined length equal to length of flagellomere III, ratio of length of flagellomere VII to VIII is 1: 16.5, flagellomere VIII elongate and plumose with microtrichia. Thorax. Black (male) or dark yellow to reddish-brown (female; red when alive), posterior portion of thorax black (katatergite, metanepisternum, metepimeron and mesopostnotum) in female suffused with black; scutum with erect, short, yellow, setal pile in male, short black setae in female; anepisternum whitish along dorsal margin (more distinct in female); scutellum black (male) orange with black suffusion laterally (female); male coxae black, fore and midcoxae yellow, hind coxa black; male legs black to brown, foretibia yellow distally, hind basitarsus dark yellow basally; female leg colour highly variable, frequently fore and mid legs either entirely yellow, hind leg usually entirely black or yellow; hind tibia and tarsus longer and thicker than other legs; haltere yellow to white; wing dark smoky infuscate, venation dark; pterostigma dark. Abdomen. Male abdomen narrow, petiolate basally, segment 1 equal to width of scutellum with segment 5 widest and equal to width of scutum, black with yellow posterolaterally on tergites 1–5; segment 1 with lateral flange well developed; female abdomen wider, variable white with black markings, black paired markings on tergites 1–2, tergite 3–4 black with white posteromedial spot and along lateral margin, remaining segments entirely black. Male genitalia. Epandrium short; gonocoxites similar to L. danielsorum sp. n., rounded with angular posterolateral processes; gonostylus bilobed and well developed; phallus relatively elongate with medial lobe only slightly longer than lateral lobes. Female genitalia not dissected.

Etymology. The species epithet is derived from the Greek di —two, and morpho —form, shape, referring to the highly distinctive sexual dimorphism in this species.

Comments. This species is very similar to L. danielsorum sp. n., as discussed above. The females of both species are remarkable wasp mimics of the hymenopteran family Braconidae occurring in the region (e.g., Campyloneurus Szepligeti , Callibracon Ashmead ). The female of L. dimorphum sp. n. varies in the colour of the head, ranging from entirely black through partly suffused with black, to entirely bright yellow (red in life) with black markings on the frons and face. Other morphological features are relatively uniform.

Type material— Holotype female, AUSTRALIA: Queensland: 16 km N of Boonah [-27.8599, 152.7328], 17.IX.1994, C.J. Burwell ( QM).

Paratypes. AUSTRALIA: Queensland: 2 males, 10 females, Oakwells site 7, [-25.8067, 148.2717], 1.X.2005, C. Eddie, 580 m, ex. stock trough, partly cleared gully, brigalow vine scrub ( QM) ; 2 females, 16 km N of Boonah [-27.8599, 152.7328], 2 IX.1987, 6–7.IX.1997, C.J. Burwell ( QM) ; 1 female, Ipswich [-27.6221, 152.7555], 24.IX.1984, M. Kewley ( QM) . New South Wales: 1 female, South West Rocks [-30.8843, 153.0344], 10.IX.1987, N.W. Rodd ( AM) ; 2 females, Wambelong Ck, Warrumbungle N.P. [-31.3231, 149.0271], Malaise trap across creek bed, 21.I–9.II.2009, S.L. Winterton ( CSCA) ; 1 female, Gunnedah [-31.0143, 150.2430], 4.IX.1962, C.W. Frazier ( ANIC) .

Figures

FIGURE 6. Lagenosoma dimorphum sp. n., female, Warrumbungle National Park, New South Wales (image copyright: Shaun L. Winterton).

FIGURE 15. A. Lagenosoma dimorphum sp. n., male, lateral view; B. Lagenosoma dimorphum sp. n., male, oblique view; C. Lagenosoma dimorphum sp. n., female (light form), oblique view; D. Lagenosoma dimorphum sp. n., female (darker form), oblique view; E. Lagenosoma dispar Brauer, male, lateral view; F. Lagenosoma dispar Brauer, male, oblique view; G. Lagenosoma dispar Brauer, female, lateral view; H. Lagenosoma dispar Brauer, female, anterolateral view.

FIGURE 20. Stylised illustrations of the antenna of Eudmeta, Ampsalis, Elissoma and Lagenosoma.

FIGURE 21. Wings. A. Elissoma brunnea Hardy; B. Lagenosoma dimorphum sp. n.; C. Lagenosoma propinquum Brauer; D. Lagenosoma pictum Brauer.

FIGURE 24. Male genitalia, (dorsal and ventral views). A. Lagenosoma clitellum sp. n.; B. Lagenosoma dimorphum sp. n.; C. Lagenosoma dispar Brauer; D. Lagenosoma pictum Brauer; E. Lagenosoma propinquum Brauer; F. Lagenosoma varigatum sp. n.

FIGURE 26. Heads of Elissoma and Lagenosoma. A. Elissoma scapula sp. n., male; B. Elissoma scapula sp. n., female; C. Lagenosoma clitellum sp. n., male; D. Lagenosoma clitellum sp. n., female; E. Lagenosoma danielsorum sp. n., male; F. Lagenosoma danielsorum sp. n., female; G. Lagenosoma dimorphum sp. n., male; H. Lagenosoma dimorphum sp. n., female (pale form); I. Lagenosoma dimorphum sp. n., female (dark form); J. Lagenosoma dimorphum sp. n., female (intermediate form); K. Lagenosoma dispar Brauer, male; L. Lagenosoma dispar Brauer, female.

FIGURE 29. Elissoma and Lagenosoma scutellums. A. Elissoma scapula sp. n., male; B. Elissoma minuta sp. n., male; C. Lagenosoma clitellum sp. n., male; D. Lagenosoma clitellum sp. n., female; E. Lagenosoma danielsorum sp. n., male; F. Lagenosoma danielsorum sp. n., female; G. Lagenosoma dimorphum sp. n., male; H. Lagenosoma dimorphum sp. n., female; I. Lagenosoma dispar Brauer, male; J. Lagenosoma dispar Brauer, female.

FIGURE 33. Lagenosoma abdomens. A. Lagenosoma danielsorum sp. n., male; B. Lagenosoma danielsorum sp. n., female; C. Lagenosoma dimorphum sp. n., male; D. Lagenosoma dimorphum sp. n., female; E. Lagenosoma dispar Brauer, male; F. Lagenosoma dispar Brauer, female; G. Lagenosoma pictum Brauer, male; H. Lagenosoma pictum Brauer, female; I. Lagenosoma propinquum Brauer, male; J. Lagenosoma propinquum Brauer, female; K. Lagenosoma varigatum sp. n., male; L. Lagenosoma varigatum sp. n., female.

FIGURE 37. Distribution of Lagenosoma species.