Lagenosoma Brauer
Creators: name: Winterton, Shaun L.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Stratiomyidae
Lagenosoma

description: Lagenosoma Brauer
Lagenosoma Brauer 1882: 81 — Hardy, 1920: 46 [as synonym of Massicyta]; Hardy, 1933: 409; Woodley, 1989: 314 [catalogue], 2001: 168 [catalogue]. Type species: Lagenosoma picta Brauer, 1882: 81, by original designation.
Peratomastix Enderlein, 1914: 311 — Kertész, 1916: 128 [key]; Hardy, 1920: 46 [checklist]; Hardy, 1933: 409 [key]; Woodley, 1989: 311 [catalogue], 2001: 131 [catalogue]. Type species: Peratomastix australis Enderlein, 1914: 311, by original designation. syn. n.
Diagnosis. Scutellar and notopleural spines absent; wing vein M 3 present; M 4 arising on discal cell, cross-vein r–m present; wing not bent over abdomen; face flat or broadly rounded, including around base of antennae, sometimes extended ventrally around buccal cavity; male eyes usually contiguous medially below ocellar tubercle; eye not pilose; male postocular ridge narrow or broadly carinate; antenna greatly elongate, scape much shorter than flagellum; flagellum cylindrical, circular sensory pits on flagellomeres I–III, flagellomeres IV–V very short and of similar length, flagellomeres VI–VII length variable; flagellomere VIII longer than all other flagellomeres, covered with shallow to deeply plumose microtrichia; abdomen narrowed basally, ovoid to strongly petiolate, frequently strongly sexually dimorphic.
Included species. Lagenosoma clitellum sp. n.; L. danielsorum sp. n.; L. dimorphum sp. n.; L. dispar Brauer, 1882 (= Peratomastix australis Enderlein, 1914 syn. n.); L. eklemmum sp. n.; L. geminatum sp. n.; L. pictum Brauer, 1882; L. propinquum Brauer, 1882; L. propius sp. n. and L. varigatum sp. n.
Comments. Lagenosoma is easily differentiated from other clitellariine genera by the absence of scutellar (cf. Campeprosopa and Elissoma) and notopleural spines (cf. Nigritomyia), a rounded or flat face (cf. Ampsalis), and abdomen narrowed anteriorly, especially in the male (cf. ovoid in Eudmeta). The distal antennal flagellomere is elongate (aristate in Geranopus and Dysbiota) and slightly to narrowly plumose (shared with Ampsalis, Lagenosoma, Elissoma and Eudmeta); all other genera have flagellomere VIII subequal to, or shorter than, one or more other flagellomeres. The male abdomen is frequently strongly petiolate while the female is slightly petiolate to broadly ovoid. Members of this genus are excellent wasp mimics, especially L. pictum. All species are distributed in mainland eastern Australia, with the greatest diversity found in Queensland (Fig. 37).
Brauer (1882) incorrectly attributed Lagenosoma to Schiner, but subsequent authors have correctly attributed the genus to Brauer. Moreover, Brauer (1882) did not list the gender of Lagenosoma, but Woodley (1989, 2001) used it in the diminutive neuter form (as it ends in – soma) (the combination describes the narrow male abdomen); the neuter form is similarly used here. Hardy (1920) listed Massicyta Walker, 1856 as a senior synonym of Lagenosoma, but as noted by Brauer (1882) when describing Lagenosoma, Massicyta is poorly defined and actually belongs in Hermetiinae. Woodley (2001) subsequently synonymised Massicyta with Hermetia Latreille, 1804. Enderlein (1914) described Peratomastix based on a damaged female specimen and placed it in Pachygastrinae; he supposed that it had three medial veins to place it in that subfamily, despite it lacking a complete wing. Placement of Peratomastix in Pachygastrinae was followed by Kertész (1916), Hardy (1920) (as Lophotellinae) and Woodley (1989, 2001). Interestingly, Hardy (1920) questioned the assumption of the medial vein complement in Peratomastix by Enderlein (1914), based on his assessment of variation in wing venation in a wide variety of Australian forms and indeed cautioned against such assumptions. Hardy (1933) in his key to genera instead suggested Lagenosoma was equivalent to Peratomastix and placed both in Hermetiinae. Based on the similarity of Peratomastix to Lagenosoma it is synonymised here and it is clear that Enderlein (1914) was incorrect both in his assumption of its wing medial vein complement and thus its placement in Pachygastrinae.
Key to species of Lagenosoma
1. Wing hyaline; scutum and scutellum entirely or partly straminous orange to brown with glossy black punctate setal bases (e.g., Fig. 16C, G); male postocular ridge slightly to strongly carinate (e.g., Figs 27C; 26C)............................. 2.
- At least part of wing smoky infuscate; scutum and scutellum colour variable, bright yellow to black, setal bases not punctate, concolourous with rest of scutum and scutellum (e.g., Fig. 15B, C); male postocular ridge rarely carinate (Fig. 26E, G)... 4.
2. Scutum black anteriorly with yellowish dorsocentral stripes (Fig. 14E, H); male abdomen strongly petiolate (segments 1–3) (Fig. 14F), abdomen ovoid in female; postocular ridge whitish (Fig. 26C, D); wing membrane in cells bm and d lacking microtrichia (Fig. 14E–H)..................................................................... L. clitellum sp. n.
- Scutum entirely dark yellow and lacking dorsocentral stripes (Fig. 16C, F, G); abdomen narrowed basally but not petiolate and not sexually dimorphic; postocular ridge concolourous with rest of head and thorax (Fig. 27A–D); wing membrane in cells bm and d with microtrichia............................................................................... 3.
3. Pleuron entirely dark yellow (Fig. 16E, H); male occiput strongly carinate (Fig. 27C)............... L. geminatum sp. n.
- Pleuron dark brownish black, extending ventrally between fore and mid coxae (katepisternum), more extensive in male (Fig. 16A, D); male occiput weakly carinate (Fig. 27A)........................................... L. eklemmum sp. n.
4. Male (eyes contiguous medially, or near so)............................................................... 5.
- Female (eyes widely separated medially)............................................................... 11 *.
5. Wing with distinct darker infuscation anteriorly (Fig. 21D); abdomen strongly petiolate (33G); scutum with yellow areas laterally on notopleuron, postalar callus and anterior to transverse suture (Fig. 17A, B).............. L. pictum Brauer (male).
- Wing with more diffuse smoky infuscation throughout; abdomen slightly narrow basally to strongly petiolate, but not globose; scutum entirely black................................................................................. 6.
6. Scutellum pale, usually yellow to white (Fig. 30E).................................. L. propinquum Brauer (male).
- Scutellum entirely black, or black anteromedially............................................................ 7.
7. Scutellum black with distinctly demarcated yellow border (Fig. 30G); margin of buccal area extended ventrally (Fig. 27I)................................................................................. L. varigatum sp. n. (male).
— Scutellum entirely brown or black...................................................................... 8.
8. Abdomen (segments 1–3) narrowed basally, sides relatively straight and diverging (Fig. 33E); area around base of antennae suffused with black (Fig. 26K; 15E, F)................................................. L. dispar Brauer (male).
- Abdomen (segments 1–3) more strongly petiolate, sides curved inwards (e.g., Fig. 33A); area around base of antennae yellow (Fig. 26E, G)....................................................................................... 9.
9. Face and area around base of antennae only slightly rounded (Fig. 27L); abdominal tergites with narrow margin of dark yellow (Figs 18A; 34B)................................................................... L. propius sp. n. (male).
- Face and area around base of antennae raised, rounded; abdomen entirely black................................. 10.
10. Head entirely yellow, face with few black setae, (Fig. 26G; 15A, B)...................... L. dimorphum sp. n. (male).
- Head dull yellow anteriorly, face with extensive black setae, occiput mostly black or suffused with black (Figs 14A, B; 26E)............................................................................ L. danielsorum sp. n. (male).
11. Abdomen strongly petiolate, globose posteriorly (Figs 17D, F; 33H)......................... L. pictum Brauer (female).
- Abdomen narrowed basally but not strongly petiolate (e.g., Fig. 33D, F, L)..................................... 12.
12. Margin of buccal area extended ventrally (Fig. 27J); scutum yellow with single broad black stripe and narrower interrupted stripe laterally (Fig. 18E); terminal flagellomere relatively short and not plumose........... L. varigatum sp. n. (female).
- Margin of buccal area not extended ventrally; scutum otherwise patterned; terminal flagellomere relatively elongate and plumose............................................................................................. 13.
13. Scutellum black, usually with narrow dark yellow margin posteriorly (Fig. 29J)............... L. dispar Brauer (female).
- Scutellum otherwise, mostly dark yellow or teal green to white.............................................. 14.
14. Scutellum dark yellow with brown-black suffusion laterally (Fig. 29H); abdomen black with distinct white intersegmental membrane (Fig. 33D)......................................................... L. dimorphum sp. n. (female).
- Scutellum uniform bright yellow (Fig. 30F) or teal green to white (Fig. 29F); abdomen uniform dark brown (Fig. 33B, J).................................................................................................... 15.
15. Scutellum bright yellow (Fig. 30F); frons unmarked (Fig. 27H)...................... L. propinquum Brauer (female).
- Scutellum teal green (tending to white in dried specimens) (Fig. 29F); frons with pair of black spots (Fig. 26F)..................................................................................... L. danielsorum sp. n. (female).
*Note: the female of L. propius sp. n. is unknown.
description: Published as part of Winterton, Shaun L., 2023, Wasp-mimicking soldier flies of the Australian Region: revision of Ampsalis Walker, Elissoma White and Lagenosoma Brauer (Stratiomyidae: Clitellariinae), pp. 1-63 in Zootaxa 5246 (1) on pages 29-31, DOI: 10.11646/zootaxa.5246.1.1, http://zenodo.org/record/7673215