Key to the Australian species of Howickia

1 Wing extending at least to posterior margin of scutellum (macropterous or brachypterous)........................... 2

- Wing absent or vestigial with vestige minute and not extending to posterior margin of scutellum (apterous or almost so)... 26

2 Wing fully developed, extending at least to posterior margin of T5.............................................. 3

- Wing significantly reduced, extending at most to posterior margin of T3......................................... 24

3 Head yellow to reddish-orange, different in colour from body.................................................. 4

- Entire body mostly brown to black, head brown to black with at most the lower frons orange......................... 9

4 CS2 at most half as long as CS3 (Figs. 24.6, 25.6); wing strongly infuscate but not patterned. Small species (1.9–3.1 mm) with 6–8 rows of acrostichal setulae........................................................................... 5

- CS2 subequal to or longer than CS3 (Figs. 8.3, 13.6, 14.6, 15.6); wing patterned or at least with dark spots at crossveins. Large species (2.5–5.5 mm) with 10–12 rows of acrostichal setulae................................................... 6

5 Frons with 4 subequal interfrontal bristles. Thorax with 10 rows of acrostichal setulae. Male mid tibia without row of stout ventral setae. R 4+5 sharply upcurved basally before running parallel to costa, never with a short appendix on the distal curve (Fig. 25.6)................................................................ H. xanthocephala sp. nov. (QLD, NSW)

- Frons with 3 interfrontal bristles (2 subequal and 1 much smaller). Thorax with 6 rows of acrostichal setulae. Male mid tibia with a double row of stout ventral setae. R 2+3 roughly symmetrically sinuate, sometimes with a short appendix on the distal curve (Fig. 22.6)................................................. H. vernalis (Richards, 1973) (NSW, QLD, VIC)

6 Head orange/caramel brown; femora apically dark, with little to no orange........................................ 7

- Head yellow; femora with at least apical fifth orange......................................................... 8

7 Wing infuscate, with light patches forming a reticulated pattern (Fig. 14.6). All interfrontal bristles long with tips crossing. Apical 3 tarsomeres of fore leg white. Halter pale brown with a white apex..................................................................................... H. myrmecophila (Knab & Malloch, 1912) (ACT, NSW, QLD, TAS)

- Wing slightly infuscate with dark spots at crossveins and midpoint of CuA (Fig. 8.3). All interfrontal bristles short with tips well separated. All tarsomeres of fore leg entirely dark brown. Halter entirely dark brown..... H. erythrocephala sp. nov. (NSW)

8 CS2 2.0x length of CS3. Legs mostly yellow, with basal 2 tarsomeres of fore leg brown and remaining tarsomeres white; fore leg yellow, mid and hind legs with basal half of femur brown; basal half of mid tibia with 5 dorsal bristles (Fig. 3.10); hind tibia with a stout apicoventral seta. Interfrontal bristles short, with tips well separated.... H. kurandensis (Richards, 1973) (QLD)

- CS2 1.5x length of CS3. Legs mostly dark brown, fore basitarsus brown and remaining tarsomeres white; fore leg brown, mid and hind legs with basal four-fifths of femur dark brown; basal half of mid tibia with 7 dorsal bristles (Fig. 3.12); hind tibia with only weak setulae apicoventrally. Interfrontal bristles long, with tips crossing or nearly so............................................................................................ H. nitidipleura (Richards, 1973) (NSW, QLD)

9 Costa ending at or extending very slightly past R 4+5 (1–2x costal width).......................................... 10

- Costa extending well beyond R 4+5 (4–7x costal width)........................................................ 14

10 Frons with 5 yellowish stripes (1 on frontal vitta and each orbital plate and interfrontal plate)........................ 11

- Frons without yellowish stripes, sometimes with shiny microtrichia on interfrontal and orbital plates but otherwise uniformly pigmented.......................................................................................... 12

11 CS2 0.3x length of CS3; R 2+3 very short, asymmetrical, curving up towards costa before running parallel to costa from which it is separated by 1x costal width (Fig. 21.6). Small species (1.7–2.6 mm) with 8 rows of acrostichal setulae.................................................................................. H. trivittata (Richards, 1973) (NSW, QLD)

- CS2 subequal to CS3; R 2+3 long, evenly sinuate and separated from costa by 3x costal width, sometimes with a very small appendage on distal curve (Fig. 19.6). Medium-sized species (2.3–3.7 mm) with 12 rows of acrostichal setulae....................................................................... H. subsinuata (Richards, 1973) (ACT, NSW, QLD)

12 Frons with pale microtomentum along interfrontal plates, giving appearance of stripes (Fig. 18.2); 4 interfrontal bristles (3 large + 1 small). CS2 subequal to CS3. Male mid tibia with a double row of ventral setae along apical half only................................................................................ H. pseudovittata sp. nov. (ACT, NSW, QLD)

- Frons reddish-brown, without pale microtomentum along interfrontal plates (Figs. 6.2, 20.2); 3 interfrontal bristles (2 large + 1 small). CS2 distinctly shorter than CS3. Male mid tibia with double row of ventral setae along entire length............ 13

13 CS2 0.5x length of CS3; R 2+3 strongly sinuate with relatively rounded curves (Fig 6.3). Two dorsocentral bristles; 6 rows of acrostichal setulae.......................................................... H. brevior (Richards, 1973) (NSW)

- CS2 0.7x length of CS3; R 2+3 strongly sinuate with curves sharply bent, almost at right angles to costa (Fig. 20.3). One dorsocentral bristle; 8 rows of acrostichal setulae............................. H. symmetrica (Richards, 1973) (NSW)

14 One dorsocentral bristle............................................................................... 15

- Two dorsocentral bristles.............................................................................. 18

15 Frons largely orange, gradually transitioning from orange on lower portion to dark brown dorsally, interfrontal plates indistinctly coloured from frons (Fig. 12.2). Three stout interfrontal bristles........... H. hardyina (Richards, 1973) (ACT, NSW, VIC)

- Frons largely black, orange limited to very front of frons but may extend upwards along the sides of the interfrontals, interfrontal plates distinctly dark (Figs. 5.2, 17.2, 23.2). Four to five long interfrontal bristles.................................. 16

16 Face deeply excavated on either side of midline with a small, flattened ventromedial triangle; 5 interfrontal bristles. Scutellar width 1.5x its length. Halter brown with apex of the knob paler.......... H. wamini sp. nov. (ACT, NSW, QLD, TAS, WA)

- Face more evenly rounded, not so excavated on either side of midline with a very small flattened ventromedial triangle, if present at all; 4 interfrontal bristles. Scutellar width 2x its length. Halter largely white with some brown............... 17

17 Mid tibia with 4 dorsal setae in proximal half (Fig. 3.13). R 2+3 evenly sinuate, distal curve with same curvature as basal curve (Fig. 17.6). Male preabdominal sclerites with enlarged punctures at the base of each seta (as in Fig. 17.3).......................................................................................... H. pertusa sp. nov. (NSW, TAS)

- Mid tibia with 3 dorsal setae in proximal half (Fig. 3.2). R 2+3 with distal curve much stronger than basal curve (Fig. 5.6). Male preabdominal sclerites with seta arising from normal sockets, not enlarged as in H. pertusa (Fig. 5.3)............................................................................................ H. biantenna sp. nov. (NSW, TAS)

18 Basal half of mid tibia with 4 dorsal bristles (2 anterodorsal, 2 posterodorsal)..................................... 19

- Basal half of mid tibia with 3 dorsal bristles (2 anterodorsal, 1 posterodorsal)..................................... 21

19 CS2 0.7–0.8x length of CS3; R 2+3 separated from costa by 2x costal width (Fig. 7.6). Frontal width 2.2x its height.Anepisternum with a shining spot on anterior margin. Halter entirely dark brown. Male mid tibia with a double row of stout ventral setae along distal two-thirds................................................ H. capitalis (Richards, 1973) (ACT, NSW, QLD)

- CS2 1.0–1.3x length of CS3; R 2+3 separated from costa by 3–5x costal width (Figs. 16.6, 24.3). Frontal width 2.5x height. Anepisternum evenly microtrichose throughout. Halter pale brown with white apex. Male mid tibia with a double row of stout ventral setae along distal half only....................................................................... 20

20 CS2 1.0x length of CS3; M 1 and M 4 well separated from wing margin (Fig. 24.3). Male preabdominal sclerites heavily sclerotized................................................................ H. wilsoni (Richards, 1973) (NSW)

- CS2 1.3x length of CS3; M 1 and M 4 extending close to wing margin (Fig. 16.6). Male preabdominal sclerites desclerotized......................................................... H. percostata (Richards, 1973) (NSW, QLD, TAS, VIC)

21 Preabdominal sclerites heavily sclerotized (Fig. 10.1). Head with a shining spot on either side of the ocellar triangle. Anepisternum, katepisternum and anepimeron largely bare and shiny. R 2+3 strongly sinuate with the basal half evenly curved before bending upwards towards the costa at a distinct angle (Fig. 10.6); halter dark brown.......................................................................................... H. fuscalis (Richards, 1973) (ACT, NSW, TAS)

- Preabdominal sclerites (especially tergites) desclerotized/reduced at least marginally, though T1–2 usually desclerotized medially (as in Fig. 9.1). Head evenly microtrichose around the ocellar triangle. Anepisternum, katepisternum and anepimeron entirely dull. R 2+3 more gently sinuate, largely running parallel to the costa (Figs. 4.6, 9.6, 11.6); halter white/pale brown.. 22

22 Dorsocentral bristles separated by 7–8 rows of acrostichal setulae. R 2+3 meeting costa at a sharper (≤60˚) angle (Fig. 9.6). Male T2 & T3 largely desclerotized posteromedially, lateral edges usually intact. Body often more reddish............................................................................ H. flaviterga (Richards, 1973) (ACT, NSW, TAS, VIC)

- Dorsocentral bristles separated by 4–6 rows of acrostichal setulae. R 2+3 meeting costa at a steeper (≥70˚) angle (Figs. 4.6, 11.6). Only male T2 desclerotized medially. Body dark brown...................................................... 23

23 Acrostichal setulae long and sparse, in 4 rows; R 2+3 separated from costa by 2x costal width (Fig. 4.6). Hind tarsus usually lighter than tibia.................................................................. H. acicula sp. nov. (TAS)

- Acrostichal setulae short and dense, in 6 rows; R 2+3 separated from costa by 4x costal width (Fig. 11.6). Hind tarsus usually concolourous with tibia........................................................ H. grandisterna sp. nov. (TAS)

24 Halter reduced but distinct, pure white; wing extending to posterior margin of T3, all veins present (Fig. 26.1). Head yellow, paler than body; all tarsi dirty white. Basal half of mid tibia with 5 dorsal bristles (2 pairs); hind tibia with a large preapical ventral spur...................................................................... H. cruspica sp. nov. (VIC)

- Halter absent or minute (brown or white if present); wing very small, extending to just past anterior edge of T2, wing veins reduced, at most costa, R 1, R 2+3, and M 1+2 present (Figs. 27.6, 28.3). Head orange-brown, not much paler than body; tarsi brownish, at most only fore tarsi whitish. Basal half of mid tibia with 2–3 dorsal bristles (1 pair); hind tibia without preapical ventral spur......................................................................................... 25

25 One orbital bristle; frons with 4 pale yellow stripes (Fig. 28.2); 3 interfrontal bristles (middle pair largest with tips crossing). One dorsocentral bristle. Halter completely absent or present as minute dark brown scale.. H. sabina (Richards, 1973) (VIC)

- Two orbital bristles; frons without pale stripes, darkened along interfrontal plates (Fig. 27.2); 3 interfrontal bristles (posterior 2 large but tips separated). Two dorsocentral bristles. Halter present as minute white knob......... H. pinnula sp. nov. (TAS)

26 One orbital bristle.................................................................................... 27

- Two orbital bristles, anterior pair sometimes small or very fine................................................ 33

27 Halter present but small (Fig. 30.1). Interfrontal bristles very fine and clustered towards lower half of frons; head shiny yellow and thorax shining reddish-brown................................................ H. australis (Papp, 1979) (VIC)

- Halter absent (as in Fig. 29.1). Interfrontal bristles usually larger, if fine then more evenly spaced on frons, not clustered towards front; head and thorax usually concolourous or nearly so, but if head yellow and thorax brown then both dull with microtrichia......................................................................................... 28

28 Thorax dark brown or black, head brown or orange......................................................... 29

- Thorax yellow to yellow-brown, head yellow to yellow brown................................................ 31

29 Frons brown or gold but always with 5 pale yellow stripes (Figs. 42.4, 42.6); frontal vitta dulled from rugose surface or microtomentum....................................................... H. regalis (Richards, 1973), in part (WA)

- Frons reddish to orange-brown and plain, never with pale yellow stripes (Figs. 29.2, 44.2); frontal vitta shiny, either smooth or finely rugose........................................................................................ 30

30 Head reddish, thorax black; frons with 3–4 narrowly separated interfrontal bristles (all subequal); face centrally concave. Legs mostly black............................................................... H. auricoma sp. nov. (NSW, VIC)

- Head brown, thorax yellow/orange; frons with 3 widely separated interfrontal bristles (first pair smallest); face centrally convex. Legs mostly yellow................................................ H. tricolor sp. nov. (NSW–Lord Howe Island)

31 Anepisternum yellow with katatergite and lower two-thirds of katepimeron dark brown (Fig. 36.1). Interfrontal bristles very fine and subequal in length.................................................... H. flavithorax (Papp, 2021) (WA)

- Anepisternum and katepimeron entirely yellow to brownish with dark brown katatergite (Figs. 42.1, 43.1). Interfrontal bristles with anterior-most pair smaller than posterior pairs.......................................................... 32

32 Frons brownish with 5 pale yellow stripes; eye large, ocelli present; bristles on head narrow (Fig. 42.2). Eight rows of acrostichal setulae present....................................................... H. regalis (Richards, 1973), in part (WA)

- Frons plain yellow; eye reduced, ocelli absent and replaced by diverging setulae; bristles on head stout (Fig. 43.2). Ten rows of acrostichal setulae present....................................... H. robustaseta sp. nov. (NSW–Lord Howe Island)

33 Frons with stripes contrasting with base colour (Figs. 38.2, 43.2)............................................... 34

- Frons without stripes (Figs. 34.2, 37.2, 40.2)............................................................... 35

34 Frons yellow without microtrichose stripes, but with 2 brown arches creating an M-shape around interfrontal bristles, sections between the interfrontals darkest (Fig. 45.2); face with a brown, transverse, median stripe; lower half of gena dark brown................................................................................. H. truemani sp. nov. (TAS)

- Frons caramel-brown with 5 golden microtomentose stripes (orbital stripes narrow and connecting to frontal vitta stripe around ocelli) (Fig. 38.2); face yellow, without a dark median stripe; gena entirely yellow............... H. irwini sp. nov. (NSW)

35 Halter present at least in a vestigial form, with a knob....................................................... 36

- Halter completely absent.............................................................................. 39

36 Body dark, head yellow to orange and contrasting with thorax................................................. 37

- Body pale, at most abdomen dark but head and thorax always concolourous...................................... 38

37 Large species (2.7–3.8 mm). Palpus greatly swollen and leaf-shaped. Legs entirely dark brown. Wing present as a minute, scalelike knob (smaller than apex of halter)................................................. H. notechis sp. nov. (TAS)

- Small species (1.3–1.8 mm). Palpus elongate, not distinctly swollen. Legs yellow with fore tibia darker. Wing entirely absent.......................................................................... H. flavipes (Papp, 2021) (NSW)

38 Katatergite pale, concolourous with rest of thorax; abdomen pale reddish. Halter noticeably reduced, brown............................................................................................... H. loligo sp. nov. (TAS)

- Katatergite dark brown, contrasting with orange-brown thorax; abdomen black. Halter normal or only slightly reduced, reddishbrown..................................................................... H. dodo (Richards, 1973) (TAS)

39 Head dark reddish or black, more-or-less concolourous with thorax............................................. 40

- Head yellow or orange, distinctly contrasting with black thorax................................................ 41

40 Thorax entirely devoid of microtrichia, appearing very shiny (Fig. 41.1). Fore and hind tibiae entirely orange. Ocelli absent................................................................... H. nuda sp. nov. (NSW–Lord Howe Island)

- Thorax covered in dense microtrichia, appearing dull (Fig. 37.1). Fore and hind tibiae largely dark brown, only distally and apically orange. Ocelli present......................................................... H. holti sp. nov. (NSW)

41 Fore tarsi and tarsomeres 3–5 of mid and hind legs (dirty) white....................... H. flagella sp. nov. (QLD, TAS)

- All tarsi reddish-brown to black......................................................................... 42

42 Female mid tibia with a very small apicoventral seta................................ H. truncata (Papp, 2021) (NSW)

- Female mid tibia with a large apicoventral seta............................................................. 43

43 Antenna reddish; head uniformly orange with some darkening around and behind ocelli; interfrontal bristles subequal. Fore legs reddish-orange, mid and hind legs bicoloured (Fig. 32.1). Abdominal setae pale orange-brown................................................................................................. H. dealata (Richards, 1973) (TAS)

- Antenna dark reddish; head dark reddish-orange with strong darkening around and behind ocelli; medial pair of interfrontal bristles slightly larger than others. Legs black with pale knees, tarsi brown (Fig. 31.1). Abdominal setae dark brown................................................................................ H. cynthia (Richards, 1973) (TAS)