Sphaeroceridae, Macquart, 1835

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 : 16-18

Key to the Australian genera of Sphaeroceridae .

This key includes all named sphaerocerid genera found in Australia, as well as two undescribed genera, and is based on Marshall & Buck’s (2010) key to the Neotropical genera. As Howickia is not easily diagnosed as a complete group using external characters alone, this key is effectively part of the diagnosis of Howickia . Genera not previously recorded from Australia are indicated by an asterisk (*).

1 Wing fully developed, extending past apex of abdomen....................................................... 2

- Wing reduced (extending at most to T4) or entirely absent............................ Howickia Richards, 1951 , in part

2 Wing cells bm and dm fused; costa extending at most halfway between R 4+5 and M; anal cell (cua) open ( LIMOSININAE ).. 5

- Wing cells bm and dm separated by crossvein; costa extending around wing tip, reaching M; anal cell (cua) closed........ 3

3 Scutellum with 4 marginal bristles, without tubercles. Wing vein M 4 not reaching wing margin. Hind tibia with dorsal bristles. Arista pubescent ( COPROMYZINAE )................................................... Norrbomia Papp, 1988

- Scutellum with stout tubercles (not bristles) along outer margin. Wing vein M 4 reaching wing margin. Hind tibia with short dorsal setulae. Arista bare ( SPHAEROCERINAE )........................................................... 4

4 Scutellum with 6–10 tubercles along posterior margin. Mesonotal setae arising from small tubercles; acrostichal setulae in 4 rows. Smaller species (2.2–2.4 mm)..................................................... Ischiolepta Lioy, 1864

- Scutellum with 2 posterolateral marginal tubercles. Mesonotal setae not arising from small tubercles; acrostichal setulae in 2 rows. Larger species (3.5–4.2 mm).................................................. Sphaerocera Latreille, 1805

5 Scutellum with 6 or more marginal bristles; usually with discal setae or setulae but disc bare in some species with a pair of small basal scutellar setae in addition to the 6 marginal bristles...................................................... 6

- Scutellum with 4 marginal bristles, disc always without setae or setulae.......................................... 9

6 Scutum with at least 1 pair of presutural dorsocentral bristles and usually more than 1 pair of postsutural dorsocentral bristles, separated by 8–10 rows of acrostichal setulae. Mid tibia with at least 2 pairs of dorsal bristles in proximal half; mid basitarsus with a stout ventral seta; mid trochanter with a strong, apical anteroventral seta. Costa ending at apex of R 4+5 ............. 7

- Scutum with only 1 pair of dorsocentral bristles, in the prescutellar position, separated by 6–8 rows of acrostichal setulae. Mid tibia with at most 1 pair of dorsal bristles in proximal half (the most proximal pair); mid basitarsus without a stout ventral seta; mid trochanter without a strong, apical anteroventral seta. Costa extending well beyond apex of R 4+5 ................... 8

7 Anterior-most pair of dorsocentral bristles reclinate. Lunule at most moderately developed. R 4+5 gently curved up; alula broad. Male cercus free from epandrium....................................................... Leptocera Olivier, 1813

- Anterior-most pair of dorsocentral bristles inclinate. Lunule strongly developed. R 4+5 only slightly curved; alula narrow. Male cercus fused with epandrium........................................................... Rachispoda Lioy, 1864

8 Scutellum with 2 pairs of strong discal setae. Anal vein sinuate.......................... Philocoprella Richards, 1929 *

- Scutellum with many discal setulae. Anal vein angulate.................................... Coproica Rondani, 1861

9 Scutum with 4–6 pairs of dorsocentral bristles, anterior presutural dorsocentral bristle inclinate. Head very broad (frontal width ≥ 1.5x frontal height) & eyes small (≤ 1.5x genal height). Body heavily microtrichose, appearing dull................................................................................................. Thoracochaeta Duda, 1918

- Scutum with 1–4 pairs of dorsocentral bristles, anterior presutural dorsocentral bristle (0–1) reclinate or (usually) absent. Head not distinctly broad (frontal width ≤ 1.4x height) & eyes not reduced (eye height ≥ 2.0x genal height). Body sparsely microtrichose, usually shiny............................................................................ 10

10 Anepisternum with posterodorsal patch of several setae................................... Pleuroseta Richards, 1973

- Anepisternum bare posterodorsally...................................................................... 11

11 Hind tibia with a large, curved, ventral preapical spur.................................. Opalimosina Roháček, 1983

- Hind tibia with only short apicoventral setae, sometimes stout but not long and curved............................. 12

12 Mesonotum with 1 pair of presutural and (1–3) pairs of postsutural dorsocentral bristles; presutural dorsocentral bristles distinctly enlarged, at least three times as long as acrostichal setulae............................................ 13

- All dorsocentral bristles (1–3) postsutural; presutural dorsocentral bristles indistinct from acrostichal setulae............ 17

13 CS2 0.5x length of CS3....................................................... Pseudopterogramma Papp, 2008

- CS2 subequal to or longer than CS3...................................................................... 14

14 Wing patterned with distinct light and dark areas........................................................... 15

- Wing clear or slightly infuscate but without any distinct patterning............................................. 16

15 Large species (2.2–2.6 mm). Scutum brown to black with silvery microtomentose spots, scutellum without dense velvety microtomentum, frons brown to reddish brown with small silvery microtomentose spots. Mid tibia with only an apicoventral bristle......................................................................... Poecilosomella Duda, 1925

- Small species (1.1–1.2 mm). Scutum brown with uniformly dense microtomentum, scutellum with dense brown velvety microtomentum, frons yellow-brown with silver-blue microtomentum on the upper half. Mid tibia with a distinct midventral bristle and an apicoventral bristle.................................................... Chaetopodella Duda, 1920 *

16 Mid basitarsus with an enlarged ventral seta. Costa extending well beyond R 4+5; R 2+3 almost straight; alula broad.......................................................................................... Undescribed genus Aus-A

- Mid basitarsus with uniformly small ventral seta. Costa ending at R 4+5; R 2+3 gently sinuate; alula narrow................................................................................................. Phthitia Enderlein, 1938

17 One to two pairs of interfrontal bristles................................................................... 18

- Three to five pairs of interfrontal bristles.................................................................. 20

18 Small species (1.0– 1.8 mm). All interfrontal bristles smaller and non-cruciate. Postpedicel pointed and conical. Acrostichal setulae sparse, in 4–6 rows between the dorsocentral bristles. Wing elongate with all veins reduced................................................................................................ Pterogrammoides Papp, 1972 *

- Large species (2.3–3.5 mm). One pair of interfrontal bristles large and cruciate. Postpedicel evenly rounded. Acrostichal setulae denser, in 8–10 rows between the dorsocentral bristles. Wing stouter with all veins strongly developed................. 19

19 One pair of interfrontal bristles, inserted close to eye margin. Mid tibia with 4–6 strong proximal posterodorsal bristles; all legs thickened, tarsi flattened........................................................ Pachytarsella Richards, 1963 *

- Two pairs of interfrontal bristles, large cruciate bristle inserted far from eye margin and surmounted by a much finer seta. Mid tibia with only a single strong proximal posterodorsal bristle; legs and tarsi simple, unmodified....................................................................................................... Undescribed genus Aus-B

20 Mid basitarsus with an enlarged ventral seta............................................................... 21

- Mid basitarsus with uniformly small ventral setae........................................................... 24

21 Acrostichal setulae large and sparse, in 5–6 rows at suture. Head with silver microtomentose patches on either side of ocellar triangle; anepisternum and katepisternum with silver microtomentum. Mid tibia with a single anterodorsal bristle in proximal half, apicoventral bristle absent. R 4+5 almost straight........................................ Opacifrons Duda, 1918

- Acrostichal setulae smaller and denser, in 8–10 rows at suture. Head brown, body without silver microtomentum. Mid tibia with at least 2 anterodorsal bristles (usually more) in the proximal half; mid tibia of female with distinct apicoventral bristle. R

4+5 gently curved or sinuate............................................................................... 22

22 Two or three pairs of dorsocentral bristles, anterior pair(s) small. CS2 longer than CS3 (1.4–2.0x)................................................................................................... Pseudocollinella Duda, 1924

- One pair of dorsocentral bristles. CS2 subequal to CS3 (0.9–1.1x).............................................. 23

23 Mid tibia with 2 anterodorsal and 2 posterodorsal bristles in proximal half; male mid tibia with an apicoventral row of stout setae. Costa ending close to the wing tip; M 1+2 extending to wing margin as a sinuate crease. Female terminalia elongated, telescopic....................................................................... Paralimosina Papp, 1973 *

- Mid tibia with only 2 anterodorsal bristles in proximal half; male mid tibia with a strong mid ventral seta and a large apicoventral bristle. Costa ending before the wing tip; M 1+2 extending slightly past dm-m. Female terminalia stout, non-telescopic................................................................................... Spinilimosina Roháček, 1983 *

24 Frons with a row of setae between the orbital and interfrontal bristles. Hind tibia with an enlarged dorsal preapical seta. Basal half of costa thickened; R 4+5 strongly curved up to costa, meeting well before wing tip............ Trachyopella Duda, 1918

- Frons with only orbital and interfrontal bristles, never with an additional row of setae between. Hind tibia with dorsal setae uniformly short. Costa evenly tapered; R 4+5 straight to gently curved, meeting costa close to wing tip.................. 25

25 Mid tibia with at least 1 pair of dorsal bristles in proximal half................................................ 26

- Mid tibia with no paired dorsal bristles in proximal half...................................................... 29

26 Abdominal tergites greatly reduced, largely membranous; T 1+2 with many long marginal setae. Wing slightly infuscate......................................................................................... Piliterga Papp, 2008 *

- Abdominal tergites well sclerotized, at most marginally desclerotized; T 1+2 with short marginal setae. Wing infuscate or patterned........................................................................................... 27

27 Small species, body length 1.1–2.2 mm. Frons with 3 pairs of interfrontal bristles. Head, scutum and scutellum with pale microtomentum creating distinct patterns. R 4+5 strongly curved. Female terminalia stout, non-telescopic............................................................................................. Parapterogramma Papp, 2008 *

- Body length 1.3–5.5 mm, usually over 2.0 mm. Frons with 3–5 pairs of interfrontal bristles. Head sometimes with 5 silvery microtomentose stripes but other parts of the body without microtomentose patterns. R 4+5 straight or slightly curved. Female terminalia narrow, telescopic........................................................................... 28

28 Mid tibia with 2 unpaired dorsal bristles on distal half. Wing infuscate with pale spots forming three distinct bands................................................................................ Acuminiseta cercalis Richards, 1973 The generic placement of Acuminiseta cercalis Richards is uncertain ( Roháček et al, 2001) but this species does not belong within the Afrotropical genus Acuminiseta Duda.

- Mid tibia with 3 dorsal bristles on distal half, 2 of which are paired. Wing infuscate or tessellated, but never with pale spots forming three distinct bands.................................................... Howickia Richards, 1951 , in part

29 Mid tibia with uniformly short ventral seta along entire length in both sexes...................................... 30

- Mid tibia with a distinct midventral seta, at least in female.................................................... 31

30 Scutum with 3 pairs of dorsocentral bristles. CS2 shorter than CS3 (0.6–0.7x); costa ending at R 4+5. Mid tibia with 2 dorsal bristles in distal half............................................................... Bifronsina Roháček, 1983

- Scutum with 1–2 pairs of dorsocentral bristles. CS2 roughly subequal to CS3 (0.9–1.1x); costa extending well past R 4+5. Mid tibia with 3 dorsal bristles in distal half................................................ Telomerina Roháček, 1983

31 Alula broad. Mid tibia with 3 closely-approximated dorsal bristles in the proximal half; male mid tibia with distinct midventral seta. Acrostichal setulae in 10–12 rows.................................................. Spelobia Spuler, 1924 *

- Alula narrow. Mid tibia with 2 widely separated dorsal bristles in the proximal half; male mid tibia with uniformly short ventral setae or row of stout apical setae, but without distinct midventral seta. Acrostichal setulae in 6–8 rows................. 32

32 R 4+5 gently upcurved to meet costa well before wing tip; costa extending well beyond apex of R 4+5; M 1 short. Male mid tibia with single apicoventral seta....................................................... Pullimosina Roháček, 1983

- R 4+5 straight, meeting costa at wing tip; costa ending at apex of R 4+5; M 1 extending to wing margin. Male mid tibia with row of stout setae in apical half................................................ Parasclerocoelus Marshall & Dong, 2008