Ampsalis Walker

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 : 10-11

Ampsalis Walker

Ampsalis Walker, 1859: 98 — Brauer, 1882: 66 [key, relationships]; Brunetti, 1920: 44, 1923: 110 [revision, synonymy]; James, 1975a: 29 [catalogue]; Woodley, 2001: 153 [catalogue]. Type species. Ampsalis geniata Walker, 1859: 99 , by monotypy.

Tracana Walker, 1859: 99 — Brauer, 1882: 66 [key, relationships]. Type species. Tracana iterabilis Walker, 1859: 99 , by monotypy.

Diagnosis. One pair of scutellar spines, size variable; notopleural spine absent; M 4 arising on discal cell, cross-vein r–m present; wing straight, not bent over abdomen; face protruding anteroventrally as ‘nose’-like process; male eyes contiguous medially below ocellar tubercle; eye not pilose; postocular ridge at most only narrowly carinate in female and not carinate in male; antenna greatly elongate, scape much shorter than flagellum; flagellum cylindrical, circular sensory pits on flagellomeres I–III, flagellomeres IV–VIII very short and of similar length, flagellomere VIII plumose and longer than all other flagellomeres combined; abdomen narrowed basally although not strongly petiolate and only slightly sexually dimorphic.

Included species. Ampsalis acta sp. n., A. geniata Walker , A. iterabilis (Walker) and A. wallacei sp. n.

Comments. Ampsalis sensu lato has traditionally been a morphologically heterogeneous genus with two very similar species originally described from Indonesia by Walker (1859) (each in Ampsalis and Tracana ) and a morphologically distinct pair of Malagasy species ( Ampsalis dichromata James, 1975b and A. terminalis James, 1960 ) described by James (1975b). The two new species described here from northern Australia are morphologically similar to the Indonesian species of Ampsalis and share the distinctive ‘nose’-like process below the antennae. This process is absent in the Malagasy species, amongst other differentiating characters, and indicates that the Malagasy species belong to a separate genus, as suggested by James (1975b) (see discussion by Hauser et al. 2017); they are treated here as Clitellariinae incertae sedis. Ampsalis is diagnosed herein based on a typological concept, now comprising only the species from Indonesia and Australia. It can be separated from all other Clitellariinae genera in these regions by the rounded, ‘nose’-like process on the face; scutellar spines present and relatively short (absent in Lagenosoma , Eudmeta and Ruba ; usually greatly elongate in Campeprosopa ); medial veins reaching the wing margin (ending prematurely in Campeprosopa ); notopleural spines absent (present in Nigritomyia , Clitellaria and Anoamyia ); distal antennal flagellomere greatly elongate (aristate in Geranopus and Dysbiota ) and narrowly plumose (shared with Lagenosoma , Elissoma and Eudmeta ) (all other genera with flagellomere VIII subequal to, or shorter than, one or more other flagellomeres); antennal flagellomeres VI–VII lacking setae distally (present in Eudmeta ); wings straight (bent over abdomen in Octarthria ) and the male eyes always contiguous (male frons usually wide in Campeprosopa ). Also apparent is the surprising similarity of the Australian Ampsalis species to members of Hermetiinae , with the nose-like process, translucent medial area of abdominal segment 2 and highly concave occiput.

Key to Ampsalis species in the Australian region and Indo-Malayan transition zone

1. Scutellar spines equal to approximately 20% of scutellum length; femora predominantly yellow with black or brown banding, especially hind leg ( Indonesia)........................................................................... 2.

- Scutellar spines minute, equal to approximately 5–10% of scutellum length (spines larger in male) ( Fig. 28A, B ); femora predominantly black to brown ( Australia)..................................................................... 3.

2. Antenna black, brownish towards base, much longer than head width; scutum yellow with dark brown stripes, lateral stripes interrupted at transverse suture; abdominal tergites brown medially, yellow laterally ( Fig. 8 )............ A. geniata Walker.

- Antenna whitish-yellow, blackish towards base, length subequal to head width; scutum uniform dark brown; abdominal tergites mostly brown, narrow yellow stripe laterally on posterior tergites ( Fig. 9 )....................... A. iterabilis (Walker) .

3. Wing mostly uniformly brown infuscate; cells bm and d with microtrichia ( Figs 1 , 7E–H ).............. A. wallacei sp. n.

- Wing mostly hyaline with faint brown infuscation behind pterostigma, in discal cell and along M vein; membrane in cells bm and d largely devoid of microtrichia ( Fig. 7A–D ).................................................. A. acta sp. n.

Figures

FIGURE 1. Ampsalis wallacei sp. n., female, Tondoon, Queensland (image copyright: Teale Britstra).

FIGURE 7. Ampsalis spp.A. Ampsalis acta sp. n., male, lateral view; B. Ampsalis acta sp. n., female, lateral view; C. Ampsalis acta sp. n., male, oblique view; D. Ampsalis acta sp. n., female, oblique view; E. Ampsalis wallacei sp. n., female, lateral view; F. Ampsalis wallacei sp. n., male, lateral view; G. Ampsalis wallacei sp. n., female, oblique view; H. Ampsalis wallacei sp. n., male, oblique view.

FIGURE 8. Ampsalis geniata Walker. A. Female lectotype, lateral view; B. same, dorsal view (images by Martin Hauser with permission of The Natural History Museum, London).

FIGURE 9. Ampsalis iterabilis (Walker). A. Male lectotype, dorsal view; B. same, lateral view (images by Robert Douglas, copyright Oxford University Museum of Natural History); C. female paralectotype, lateral view (images by Martin Hauser with permission of The Natural History Museum, London).

FIGURE 28. Ampsalis and Elissoma scutellums.A. Ampsalis acta sp. n.; B. Ampsalis wallacei sp. n.; C. Elissoma australis sp. n.; D. Elissoma brunnea Hardy; E. Elissoma danielsi sp. n., F. Elissoma gilva sp. n.; G. Elissoma hespera sp. n.; H. Elissoma hauseri sp. n.; I. Elissoma ichneumonoides sp. n.; J. Elissoma lauta White.