Asindulum, Latreille

Fitzgerald, Scott J., 2023, The Nearctic species of Asindulum Latreille and Macrorrhyncha Winnertz (Diptera: Keroplatidae), Zootaxa 5351 (1), pp. 72-106 : 74

Key to Asindulum and Nearctic Macrorrhyncha (based on males, but including characters to help distinguish females where possible)

1a CuP distinctly reaching wing margin ( Fig. 6 top, Fig. 18 ); anterior spiracle without posterior setae ( Figs. 2, 4 )… ( Asindulum )................................................................................................... 2

1b CuP not or not distinctly reaching wing margin ( Figs. 66 , 75 ); anterior spiracle with short black posterior setae ( Fig. 77 )… ( Macrorrhyncha )..................................................................................... 7

2a Labellum very long and slender, reaching well beyond apex of fore coxa ( Figs. 2 , 5 ); male tergite 9 with two pairs of lobes: a posterolateral and a posterosubmedian pair ( Figs. 7, 9 )....................................................... 3

2b Labellum shorter and stouter, at most reaching slightly beyond apex of fore coxa ( Fig. 4 ); male tergite 9 with or without posterolateral lobes and lacking posterosubmedian lobes (e.g., Figs. 19 , 30 , 39 )................................... 4

3a Coxae black ( Figs. 51–52 ); posterosubmedian lobes of male tergite 9 more spathulate apically ( Figs. 55, 57 ), gonostylus with a pronounced basolateral swelling ( Figs. 58–59 ); Palearctic............................... Asindulum nigrum Latreille

3b Coxae cream to pale yellowish ( Fig. 5 ); posterosubmedian lobes of male tergite 9 less spathulate apically ( Figs. 7, 9 ), gonostylus without a pronounced basolateral swelling ( Fig. 10 ); Nearctic ............................... Asindulum coxale Loew

4a Male tergite 9 without posterolateral lobes, gonocoxites posteromedially drawn out into a pair of finger-like lobes each bearing several setae ( Matile 1975, figs. 7–8, and Chandler 1994, figs. 17–18); female terminalia ( Fig. 63 and as in Matile 1975, fig. 10); Palearctic, Israel.............................................................. Asindulum theodori Matile

4b Male tergite 9 with well-developed posterolateral lobes ( Figs. 19, 21 , 30, 32 , 39, 41 ) and terminalia not as above; Nearctic .. 5

5a Posterolateral corners of male tergite 9 each produced into a laterally-compressed, dorsally-curved hook/spine ( Figs. 19, 21 , 39, 41 ); usually larger species (wing length in males 5.5–7.0 mm, females 7.0–9.0 mm) with abdomen usually yellow to orangish on one half and darker on the other half (but see variation in descriptions) ( Figs. 16 , 25 , 38 , 50 ); in ventral view, female sternite 10 with or without a posterior notch...................................................................... 6

5b Posterolateral corners of male tergite 9 not produced into a dorsally-curved hook/spine, male terminalia as Figs. 30–35 ; usually smaller species (wing length ca. 4.0 mm) with abdominal color not distinctly darker at one end (though only known from two specimens); in ventral view, female sternite 10 without a posterior notch................... Asindulum mexicanum n. sp.

6a Posterolateral corner of male tergite 9 with broad, laterally-flattened, apically hooked lobe ( Figs. 19, 21 ); lateral lobes of gonocoxites apically broadly truncate and without a thumb-like lobe (dorsal process, dp) on the dorsal edge ( Fig. 21 ); female sternite 10 without a distinct posterior notch ( Figs. 26–27 ); abdominal color rather variable. Pale morph males usually with abdominal segments 1–4 yellow and remainder of segments blackish/brownish-yellow ( Fig. 16 ) and female abdomen mostly yellowish with brown posterior borders on tergites 1–3 ( Fig. 25 ). Dark morph males with all tergites dark brown to black except tergite 4 yellowish and females with tergites 1–3 dark brown to black and remainder yellowish... Asindulum flavidum n. sp.

6b Posterolateral corner of male tergite 9 with narrow, laterally-flattened, hook-like lobe ( Figs. 39, 41 ); lateral lobes of gonocoxites apically broadly rounded and with a thumb-like lobe (dorsal process, dp) on the dorsal edge ( Fig. 41 ); female sternite 10 with a posterior notch ( Figs. 47–48 ); abdomen of both sexes with segments 1–3 usually dark brown and remaining segments orangish to brownish-orange (segment 4 typically brightest) ( Figs. 38 , 50 ) though some females with even the brown tergites tinged with yellowish-orange............................................................... Asindulum montanum Röder

7a Thorax yellow and mouthparts terminating near apex of fore coxae ( Figs. 75–76 ); male terminalia as Figs. 78–83 ; female unknown............................................................................ M. vockerothi n. sp.

7b Thorax dark brown and mouthparts terminating far beyond apex of fore coxae ( Figs. 64–65 ); male terminalia as Figs. 67–72 ; female (tentatively associated; see Comments under this species)................................. M. borealis n. sp.

Figures

FIGURE 5. Asindulum coxale, male habitus. Scale = ca. 1.0 mm.

FIGURE 6. Holotype female of Asindulum coxale and labels. Clockwise spiral from top: Wing, scale bar = 1.0 mm. Head (anterior), scale bar = 1.0 mm. Habitus (anteroventral), scale bar = 2.0 mm. Habitus (posterodorsal), scale bar = 2.0 mm. Habitus (lateral), scale bar = 2.0 mm. Type labels. Photos by Charles Whittemore Farnum, credited to, and used with permission by, Museum of Comparative Zoology, Harvard University. Abbreviations: cx1, coxa 1; lbl, labellum.

FIGURE 38. Asindulum montanum, male habitus. Scale = ca. 1.0 mm.

FIGURE 66. Macrorrhyncha borealis n. sp., holotype male. 64. Wing. Scale = ca. 0.5 mm. Abbreviations: CuP, posterior branch of cubital vein.

FIGURES 16–18. Asindulum flavidum n. sp., holotype male. 16. Habitus, lateral. 17. Head, anterior. 18. Wing. Scale bars = ca. 1.0 mm. Abbreviations: CuP, posterior branch of cubital vein; cx1, coxa 1; lbl, labellum.

FIGURES 1–4. Asindulum heads, males. 1. A. coxale, anterior. 2. A. coxale, lateral. 3. A. montanum, anterior. 4. A. montanum, lateral. Scale bars = ca. 0.5 mm. Abbreviations: asp, anterior spiracle; clyp, clypeus; cx1, coxa 1; hyphar, hypopharynx; lab, labium, lbl, labellum; lbr, labrum; mx, maxilla; plp, palpus.

FIGURES 75–77. Macrorrhyncha vockerothi n. sp., male. 75. Holotype, habitus. 76. Head and anterior thorax with box indicating area of enlarged anterior spiracle. 77.Anterior spiracle. Scale = ca. 1.0 mm (FIGS. 76–77 not to scale).Abbreviations: asp, anterior spiracle; cx1, coxa 1; CuP, posterior branch of cubital vein.

FIGURES 7–10. Asindulum coxale, male terminalia. 7. Dorsal. 8. Ventral. 9. Lateral. 10. Gonostylus, posterolateral (not to scale). Scale bar = ca. 0.5 mm. Abbreviations: ce, cercus; gc, gonocoxite; gs, gonostylus; llgc, lateral lobe of gonocoxite; llt9, lateral lobe of tergite 9; smlt9, submedian lobe of t9; t9, tergite 9.

FIGURES 19–22. Asindulum flavidum n. sp., male terminalia.19. Dorsal. 20. Ventral. 21. Lateral. 22. Gonostylus, posterolateral (not to scale). Scale bar = ca. 0.5 mm.Abbreviations: ce, cercus; gc, gonocoxite; gs, gonostylus; hp, hypoproct; llgc, lateral lobe of gonocoxite; llt9, lateral lobe of tergite 9; t9, tergite 9.

FIGURES 30–33. Asindulum mexicanus, holotype male, terminalia. 30. Dorsal. 31. Ventral. 32. Lateral. 33. Gonostylus, posterolateral (not to scale). Scale bar = ca. 0.25 mm. Abbreviations: dp, dorsal process of gonocoxite; gc, gonocoxite; gs, gonostylus; llgc, lateral lobe of gonocoxite; llt9, lateral lobe of tergite 9; t9, tergite 9.

FIGURES 39–43. Asindulum montanum, male terminalia. 39. Dorsal. 40. Ventral. 41. Lateral. 42. Posterior. 43. Gonostylus, posterolateral. Scale bar = ca. 0.25 mm. Abbreviations: ce, cercus; dp, dorsal process of gonocoxite; gc, gonocoxite; gs, gonostylus; llgc, lateral lobe of gonocoxite; llt9, lateral lobe of tergite 9; sp, sperm pump; t8, tergite 8; t9, tergite 9.

FIGURES 51–54. Asindulum nigrum. 51. Male habitus. Scale = ca. 1.0 mm. 52. Male head, anterior. Scale = ca. 0.5 mm. 53. Female terminalia, dorsal. Scale = ca. 0.5 mm. 54. Female terminalia, ventral. Scale = ca. 0.5 mm. Abbreviations: cx1, coxa 1; cx2, coxa 2, ce, cercus; lbl, labellum; s7, sternite 7; s8, sternite 8; s10, sternite 10; t7, tergite 7.

FIGURES 55–59. Asindulum nigrum, male terminalia. 55. Dorsal. 56. Ventral. 57. Lateral. 58. Gonostylus, posterolateral (not to scale). 59. Gonostylus, posteroventral (not to scale). Scale bar = ca. 0.5 mm. Abbreviations: ce, cercus; gc, gonocoxite; gs, gonostylus; llgc, lateral lobe of gonocoxite; llt9, lateral lobe of tergite 9; smlt9, submedian lobe of t9; t9, tergite 9.

FIGURES 62–63. Asindulum theodori. 62. Female habitus. Scale = ca. 1.0 mm. 63. Female terminalia, posterolateral. Scale = ca. 0.25 mm. Abbreviations: ce, cercus; s8, sternite 8.

FIGURES 25–27. Asindulum flavidum n. sp., female. 25. Abdomen, posterodorsal. Scale = ca. 1.0 mm. 26. Terminalia, dorsal. Scale = ca. 0.5 mm. 27. Terminalia, ventral. Scale = ca. 0.5 mm. Abbreviations: ce, cercus; s7, sternite 7; s8, sternite 8; s10, sternite 10; t7, tergite 7.

FIGURES 47–50.Asindulum montanum, female terminalia and abdomen. 47.Terminalia, dorsal. 48. Terminalia, posteroventral. 49. Terminalia, posterolateral. 50. Abdomen, dorsal. Scale for Figs. 47–49 = ca. 0.25 mm and for Fig. 50 = ca. 1.0 mm Abbreviations: ce, cercus; s8, sternite 8; s10, sternite 10; t7, tergite 7.

FIGURES 78–81. Macrorrhyncha vockerothi n. sp., holotype male, terminalia. 67. Dorsal. 68. Ventral. 69. Lateral. 70. Posterior with inset showing enlarged gonostylus (inset not to scale). Scale bar = ca. 0.25 mm.Abbreviations: bl, basal lobe of gonostylus; ce, cercus; dp, dorsal process of gonocoxite; gc, gonocoxite; gs, gonostylus; ip, inner process of gonocoxite; s8, sternite 8; t8, tergite 8; t9, tergite 9.

FIGURES 82–83. Macrorrhyncha vockerothi n. sp., holotype male, terminalia including sperm pump. 82. Lateral. 83. Ventral. Scale = ca. 0.25 mm. Abbreviations: da, dorsal apodeme; ea, ejaculatory apodeme; gc, gonocoxite; t9, tergite 9; va, ventral apodeme;?, short divergent dorsal pair of apodemes (see Discussion).

FIGURES 64–65. Macrorrhyncha borealis n. sp., holotype male. 64. Habitus. Scale = ca. 1.0 mm. 65. Head, anterolateral. Scale = ca. 0.5 mm. Abbreviations: cx1, coxa 1; lbl, labellum.

FIGURES 67–70. Macrorrhyncha borealis n. sp., holotype male, terminalia. 67. Dorsal. 68. Ventral. 69. Lateral. 70. Posterior. Scale bar = ca. 0.25 mm.Abbreviations: bl, basal lobe of gonostylus; ce, cercus; dp, dorsal process of gonocoxite; gc, gonocoxite; gs, gonostylus; t9, tergite 9.

FIGURES 71–72. Macrorrhyncha borealis n. sp., holotype male, terminalia including sperm pump. 71. Ventral. 72. Lateral. Scale = ca. 0.25 mm. Abbreviations: ea, ejaculatory apodeme; gc, gonocoxite; t9, tergite 9.