Borboroides, Malloch, 1925

McAlpine, DK, 2007, Review of the Borboroidini or Wombat Flies (Diptera: Heteromyzidae), with Reconsideration of the Status of Families Heleomyzidae and Sphaeroceridae, and Descriptions of Femoral Gland-baskets, Records of the Australian Museum 59, pp. 143-219 : 158-162

Key to species of Borboroides

1 Face almost entirely bare and glossy; arista largely white, yellow basally; dorsocentral bristles 1+2; mesoscutum without setulae ( perkinsi group) ...................................................................................................... perkinsi (p. 176)

—— Face entirely pruinescent; arista brown to blackish; dorsocentral bristles 0+1, 0+2, or 0+3; mesoscutum setulose, at least on central part ................................................................................................................................ 2

2 Mesopleuron (anepisternite) without setulae; mid tibia with large posterior (as distinct from posteroventral) subapical spur; vein 5 almost straight where it borders on discal cell ( Fig. 38); length of discal cell at least 3× distance of its posterodistal angle from margin measured in direction of distal section of vein 5 ( stewarti group) .................................................................................................. 3

—— Mesopleuron setulose ( Fig. 102); mid tibia usually without posterior subapical spur; vein 5 usually distinctly curved outwards where it borders on discal cell ( Figs 98, 104); length of discal cell much less than 3× distance of its posterodistal angle from margin ............................................. 15

3 Females .......................................................................................................................................... 4

—— Males .............................................................................................................................................. 9

4 Abdominal segment 5 reduced in size, forming part of retractile postabdomen ( Figs 36, 37), with relatively small tergite; mid tibia always without ventral bristle other than subapical spur ............................................................... 5

—— Segment 5 forming obvious part of ovoid preabdomen, its tergite almost as long as tergite 4; mid tibial armature variable ............................................................... 6

5 Anterior fronto-orbital bristle proclinate; mesopleuron thinly pruinescent, with glossy bare zone restricted to anteroventral quarter; mesoscutum tawny-yellow with median brown stripe narrowed anteriorly and sublateral postsutural brown mark; abdominal tergite 4 not margined; tergite 5 almost parallel- sided ( Fig. 36) ......................................................................................................... musica (p. 164)

—— Anterior fronto-orbital bristle eclinate; mesopleuron with large glossy bare central zone, pruinescent posteriorly and anterodorsally; mesoscutum much more extensively brown to black, but partly fading in old specimens; abdominal tergite 4 margined, i.e. with groove parallel to lateral margin setting off convex marginal ridge; tergite 5 almost semicircular ( Fig. 37) ........................................................ donaldi (p. 173)

6 Mesoscutum tawny-yellow, usually with median brown stripe and sublateral brown mark; mid tibia without ventral bristles except near apex ................................................................................................................ stewarti (p. 162)

—— Mesoscutum with more extensive black to dark grey coloration; mid tibia usually with one or more ventral bristles near or before mid-length ...................................................................................................................................... 7

7 Prelabrum and lower part of occipital region brown to black; mid tibia with a series of 2 to 4 short ventral bristles in addition to subapical ventral spur; tergite 5 extensively dull, pruinescent, particularly on broad median zone and on lateral margins .................................... danielsi (p. 167)

—— Prelabrum and lower half of occipital region yellow or tawnyyellow; mid tibia generally with one long ventral bristle in addition to subapical spur; tergite 5 largely glossy, pruinescent mainly on anterior and posterior margins ........................................................................... 8 8 Anterior fronto-orbital bristle not more than half as long as posterior one, slightly reclinate; hind femur with only one anterodorsal bristle, in addition to any small subapical one; abdominal sternite 5 less than 1.4× as long as sternite 4, entirely densely pruinescent ............................................................................................................. tonnoiri (p. 171)

—— Anterior fronto-orbital bristle more than half as long as posterior one, slightly proclinate; hind femur usually with two longitudinally aligned anterodorsal bristles in addition to small subapical one; abdominal sternite 5 more than 1.5× as long as sternite 4, much of posterior third only thinly pruinescent and shining ...................................................................................... lindsayae (p. 169)

9 Mid tibia with long ventral mollisetae, many of them more than twice as long as tibial diameter ( Fig. 52) ..................................................................................... 10

—— Mid tibia with any mollisetae short and inconspicuous ( Fig. 28) ................................................ 11

10 Anterior fronto-orbital bristle reclinate and slightly sloped outwards, up to c. half as long as posterior one; intradorsocentral setulae in pair of paramedian series, with very few setulae between these and line of dorsocentral bristles; cercus with dense, conspicuous armature of bristles and mollisetae ( Fig. 51) .................................... tonnoiri (p. 171)

—— Anterior fronto-orbital bristle eclinate and slightly sloped forwards, c. two-thirds as long as posterior one; intradorsocentral setulae in two well-developed pairs of series; cercus with relatively sparse, inconspicuous setulae and mollisetae ( Fig. 50) .................................................. lindsayae (p. 169)

11 Hind tibia strongly curved and attenuated basally ( Fig. 30); cercus small, with setulae short in single marginal series plus pair on dorsobasal prominence; mesoscutum tawny-yellow, with median brown stripe and sometimes pair of brown sublateral marks ...................................................................................................................... stewarti (p. 162)

—— Hind tibia almost straight; cercus generally larger, with different arrangement of setulae; thorax variably marked, sometimes much darker than above ............................................................................................................... 12

12 Anterior fronto-orbital bristle proclinate; cercus with conspicuous brush of long mollisetae; mesoscutum tawny-yellow with median and sublateral brown stripes ....................................................................... musica (p. 164)

—— Anterior fronto-orbital not proclinate; mollisetae on cercus less developed; mesoscutum of different coloration ........................................................................... 13

13 Mesopleuron with large central bare glossy zone (pruinescent towards dorsal and posterior margins); middle dorsocentral bristle slightly shorter than anterior one (rarely vestigial) ................................................ donaldi (p. 173)

—— Mesopleuron densely pruinescent except near anteroventral angle; middle dorsocentral bristle about as long as anterior one ............................................................ 14

14 Entire occiput and prelabrum, and at least part of face and fore coxa brown to blackish; cheek less than half as high as eye; surstylus broad, less than twice as long as wide ..................................................... danielsi (p. 167)

—— Lower occiput, prelabrum, face and fore coxa tawny-yellow; cheek c. half as high as eye; surstylus at least three times as long as width at mid-length ........................................................................ probable variant of lindsayae (p. 169)

15 Anal cell open distally ( Fig. 92); arista more than 1.5× as long as maximum diameter of eye; mid femur with only one well differentiated anterior bristle ( Fig. 91); male: epandrium less than 0.13 mm long ( parva group) ............................................................................. parva (p. 187)

—— Anal cell closed ( Fig. 76); arista usually less than 1.5× as long as maximum diameter of eye; mid femur with a series of well differentiated anterior bristles; male: epandrium more than 0.22 mm long ....................................................................................................................... 16

16 Fronto-orbital bristles two large pairs, anterior one long, directed outwards ( Fig. 109); abdominal sternite 1 well sclerotized on whole width; distal section of vein 6 usually less than twice as long as anal crossvein ( atra group) ......................................................................................... 17

—— Fronto-orbital bristles one large pair, sometimes also a much smaller reclinate anterior pair ( Figs 65, 80); abdominal sternite 1 reduced, sclerotized mainly at sides; distal section of vein 6 at least twice as long as anal crossvein ..................................................................................... 27

17 Dorsocentral bristles three well-developed pairs; prescutellar acrostichal bristle developed; pleural region with narrow zone of dense grey pruinescence covering entire margin of fore coxal foramen; subapical anteroventral spur of hind tibia much longer than tibial diameter ( Fig. 103); wing veins mostly yellowish ............................................................................................................ gorodkovi (p. 193)

—— Dorsocentral bristles usually one or two pairs; prescutellar acrostichal bristle undifferentiated or almost so; pleural region bordering fore coxal foramen shining, at least on upper part, with little pruinescence mainly towards lower part of foramen; subapical anteroventral spur of hind tibia generally not distinctly longer than tibial diameter, sometimes minute; wing veins brown ........................................................ 18

18 Dorsocentral bristles two, anterior one nearly as long as posterior one; section of costa on second costal cell with numerous setulae as long as or longer than width of cell; anal crossvein very oblique on large part, so as to make posterodistal angle of anal cell very obtuse; subapical anteroventral spur of hind tibia absent; male: cerci complex, fused basally, but forming pair of long, free distal lobes, the whole complex longer than epandrium ( Fig. 99) ............................................. menura (p. 190)

—— Only one long (posterior) dorsocentral bristle present, any others quite small; section of costa on second costal cell with setulae all shorter than width of cell; anal crossvein almost transverse or slightly sloping distad posteriorly; subapical anteroventral spur of hind tibia usually distinct (vestigial in B. merzi ); male: cercus much shorter than epandrium ................................................................................. 19

19 Postfrons, including part in front of anterior ocellus, dull-pruinescent ( Fig. 109); cheek c. half as high as eye; mesopleuron with very extensive posterior grey-pruinescent zone; male: protandrium stout, as broad as epandrium ........................................................................................................ 20

—— Postfrons with distinct, sometimes small, ovate to subtriangular glossy zone in front of anterior ocellus ( Figs. 121, 140), or more extensively glossy; height of cheek usually less than half height of eye; mesopleuron with less extensive posterior pruinescent zone; male: protandrium usually more slender than epandrium, at least posteriorly from mid-length ............................................................................................. 21

20 Postfrons with black ground colour, sometimes tending dark brown anteriorly; cheek entirely black; palpus dark grey to black; male: fore tibia with anteroventral concavity near mid-length; surstylus ( Figs 117, 118) basally transversely broadened, curved before mid-length, with slender almost straight distal section directed posteroventrally, without preapical gibbosity ..................................................... corynetes (p. 198)

—— Postfrons partly black, with anterior margin yellow to orange- tawny, more conspicuously so in male; cheek yellowish anteriorly, at least in male; palpus yellow to yellow-brown; male: fore tibia without anteroventral concavity; surstylus ( Figs 114, 115) somewhat variable with distal section not posteriorly inclined, typically with posterior preapical gibbosity .............................................................. shippi (p. 195) 21 Capitellum of halter grey-brown; male: surstylus with large anterior, outwardly inclined rounded tubercle at base ( Fig. 149); cercus dorsally fused to epandrium ............................................................................. atra (p. 211)

—— Capitellum yellow or whitish; male: surstylus without such outwardly inclined tubercle; cercus articulated with epandrium ...................................................... 22

22 Postfrons with small median glossy zone, much narrower than lateral subshining (non-pruinescent) zone ( Fig. 121); cheek more than one third as high as eye; male: segment 8 slender throughout; epandrium very broad; cerci clavate, narrow and widely separated basally ( Fig. 123) ....................................................................... petiolus (p. 200)

—— Postfrons with larger median glossy zone, c. as wide as or wider than lateral subshining zone ( Figs 125, 130); cheek usually one third as high as eye or less; male: abdominal segment 8 widened anteriorly or moderately broad throughout; epandrium less than twice as broad as segment 8; cerci variable but not widely separated and clavate ....................................................................................................... 23

23 Postfrons very extensively shining, with little pruinescence even on anterior half; male: epandrium on each side with two large anteroventral bristles, each at least one third as long as epandrium; surstylus distally on inner surface armed with complex, fascicle-like spines; cercus rod-like, long and slender ( Fig. 154); habitat southwestern Australia............................................................................ woodhilli (p. 212)

—— Postfrons pruinescent on much of anterior half; male: epandrium without such large bristles; surstylus with simple spines and/or setulae only; cercus relatively broad, not rod-like; habitat eastern Australia (including Tasmania) ................................................................................................... 24

24 Postfrons with pair of sublateral shining zones resembling median glossy zone, but not fused with it; subapical spur of hind tibia nearly as long as greatest diameter of tibia; male: surstylus only slightly widened basally, almost straight; cercus plate-like, with very long fringe of mollisetae ( Fig. 129); female: tergite 5 with median grey-pruinescent zone on full length .......................................................... fimbria (p. 203)

—— Postfrons either without markedly shining sublateral zones extending in front of level of anterior ocellus, or median and sublateral zones fused to form broad shining zone; subapical spur of hind tibia generally much shorter than greatest diameter of tibia or indistinguishable; male: surstylus very broad basally, curved; cercus with short setulae only; female (unknown in B. acumen ): tergite 5 pruinescent anteriorly, but without such complete median pruinescent zone ...................................................................................... 25

25 Male: protandrium scarcely narrowed posteriorly; epandrium ( Fig. 142) broadly attached to protandrium, dorsobasally prominent and, when in anteriorly flexed position, projecting posteriorly beyond end of protandrium; cercus small, transverse; female: tergite 6 undivided; cercus slightly bulbous apically ............................................................... merzi (p. 206)

—— Male: protandrium narrowed posteriorly; epandrium shortly attenuated at base and not strongly projecting; cercus large, transversely compressed; female (unknown in B. acumen ): tergite 6 divided by median desclerotization; cercus not thickened apically ............................................. 26

26 Postfrons with subtriangular, median glossy zone, but without markedly shining non-pruinescent lateral zones extending in front of level of anterior ocellus; male: surstylus ( Fig. 133) with large, broadly rounded anterior basal dilation, its slender apex directed anteriorly; cercus ovate, obtuse ................................................................ bulberti (p. 205)

—— Postfrons with lateral glossy zones fused with median zone to form broad glossy zone extending in front of anterior ocellus; male: surstylus ( Fig. 146) broadly spatulate, without such rounded anterior basal expansion; cercus broad, shortly narrowed to subacute apex ..................................................................................................... acumen (p. 209)

27 Postfrons in front of level of anterior ocellus entirely dull, with fingerprint sculpture and / or pruinescence; sternopleuron almost entirely densely pruinescent ( staniochi group) ............................................................................ 28

—— Postfrons with extensive smooth, glossy zone in front of anterior ocellus; sternopleuron shining and bare, at least in part ( helenae group) ............................................................................................................................ 29

28 Mesopleuron very extensively pruinescent, glossy only on small zone near anterior margin ( Fig. 66); cheek yellow in large part (at least in male); mid tibia in both sexes with well-developed subapical posterior spur and ventral spur; distal section of vein 6 extending three quarters of distance from anal crossvein to posterior wing margin; male: cercus ( Fig. 67) small and narrow ................................ dayi (p. 178)

—— Mesopleuron glossy centrally and anteriorly ( Fig. 74); cheek entirely black to dark brown; mid tibia in both sexes with at most very small subapical posterior spur, with subapical ventral spur in female only; distal section of vein 6 extending no more than two thirds distance to margin; male: cercus ( Figs 77, 79) broad ................................ staniochi (p. 180)

29 Mesopleuron largely glossy black, with small pruinescent zone on dorsal margin only ( Fig. 81); fore femur with at least three long posteroventral bristles, but no anteroventral comb; fore tarsus entirely brown; capitellum of halter yellowish brown to dark brown ......................................................................................................... helenae (p. 183)

—— Mesopleuron extensively pruinescent, on both dorsal and posterior margins; fore femur with posteroventral bristles little developed, but, in male only, with comb of stout, moderately short anteroventral bristles; fore tarsus bicoloured, segment 1 dark brown, segments 2 to 5 pale yellowish; capitellum of halter creamy-white ....................................................................................................... doreenae (p. 186)