Miridiba Reitter, 1902

Gao, Chuan-bu & Coca-Abia, María Milagro, 2021, Revision of the genus Miridiba Reitter, 1902 (Coleoptera, Scarabaeidae, Melolonthinae): genital morphotypes and new taxonomic data, European Journal of Taxonomy 749, pp. 1-94 : 83-87

Key to the species of Miridiba Reitter, 1902

The species considered incertae sedis as well as M. brancucci , M. malaccensis and M. newari are not included in this key because of lack of sufficient information about diagnostic characters.

1. Antennae 9-segmented (genital morphotypes I, IX) ......................................................................... 2

– Antennae 10 segmented (genital morphotypes II-VIII) .................................................................. 31

2. Dorsal pubescence present. At least some part of dorsum (head, pronotum or elytra) with pubescence ........................................................................................................................................ 3

– Dorsum glabrous, at most, with tiny setae in each puncture, hardly visible even at high magnification .................................................................................................................................. 13

3. Only some part of the dorsum with pubescence (pronotum, or head and elytra) ............................. 4

– Dorsal pubescence present on whole dorsum (head, pronotum and elytra) ..................................... 6

4. Pronotum with pubescence arranged in a tuft in the centre of the surface. Head and elytra glabrous ............................................................................................................. M. sus ( Moser, 1912)

– Head and elytra pubescent. Pronotal surface glabrous ..................................................................... 5

5. Long pubescence on frons and basal part of elytra. Pronotum with lateral margins smooth ............. ............................................................................................................. M. frontalis ( Fairmaire, 1886)

– Strong pubescence on head and basal and lateral parts of elytra. Pronotum with lateral margins strongly serrated ................................................................................... M. kuraruana Nomura, 1977

6. Dorsal pubescence long, dishevelled ................................................................................................ 7

– Dorsal pubescence short and decumbent .......................................................................................... 9

7. Clypeus with anterior edge almost straight .................................. M. trichophora ( Fairmaire, 1891)

– Clypeus with anterior edge moderately emarginate ......................................................................... 8

8. Body length 16.3–20.5 mm. Anterolateral angles of pronotum weakly protuberant. Parameres with outer margin of the dorsal branches with two reflex points, and with a row of setae in dorsal view. Characters from Li et al. (2015)....................................................................... M. hirsuta Itoh, 2001

– Body length 14.1–15.5 mm. Anterolateral angles of pronotum moderately protuberant with obtusely curved anterior margin. Parameres with the tip of dorsal branches prolonged and smoothly curved downwardly below the ventral branches; parameres with dorsal branches smoothly curved and glabrous in dorsal view. Characters from Li et al. (2015)....................... M. taipei Wang & Li, 2015

9. Pronotum, elytra and scutellum with pubescence very short, observable with high magnification ... ............................................................................................................. M. huesiotoi Li & Yang, 2015

– Pubescence on pronotum, elytra and scutellum distinctly long ...................................................... 10

10. Pronotum with anterior margin moderately concave at lateral ends .......... M. taoi Li & Wang, 2015

– Pronotal anterior margin without concavities at lateral ends ...........................................................11

11. Elytra irregularly pubescent, setae on basal part longer than those on elytral surface ....................... ...................................................................................................................... M. wangi ( Zhang, 1997)

– Elytra regularly pubescent on all surface ........................................................................................ 12

12. Ratio between dorsal and ventral branches of parameres 1.25. Tips of the dorsal branches of the parameres bent downward 55º. Characters from Gao et al. (2018). Dorsal surface of metatibia with spines equidistant and close to each other ............................................... M. pilosella ( Moser, 1908)

– Ratio between dorsal and ventral branches of parameres 1.50. Tips of the dorsal branches of the parameres bent downward 30º. Characters from Gao et al. (2018). Dorsal surface of metatibia with spines not equidistant, distance between the last two spines, at least, three times greater than the distance between the anterior ones ............................................. M. kuatunensis Gao & Fang, 2018

13. Middle of anterior clypeal edge deeply emarginate ........................................................................ 14

– Middle of anterior clypeal edge moderately emarginated, widely sinuous, or almost straight ....... 16

14. Meso- and metatibiae with complete transverse carina. Dorsal branches of parameres abruptly curved downwardly, with long pubescence on dorsal surface. Ventral branches of parameres curved upwardly, with long pubescence on ventral surface .................................. M. hybrida ( Moser, 1912)

– Meso- and metatibiae with transverse carina interrupted. Dorsal branches of parameres almost straight or with additional apical extensions, without pubescence on dorsal surface. Ventral branches of parameres straight without pubescence ...................................................................................... 15

15. Anterior edge of clypeus depressed at middle, with the bottom of the depression flat, U-shaped. Dorsal branches of the parameres bearing long pubescence ventrally; without apical extensions ................................................................................................. M. bilobata (Moser, 1913)

– Anterior edge of clypeus depressed at middle, with the depression V-shaped. Dorsal branches of parameres without pubescence; with two apical extensions projecting dorsally and ventrally. Characters Keith & Sabatinelli (2010)................................ M. furcillata Keith & Sabatinelli, 2010

16. Frontal carina moderately developed .............................................................................................. 17

– Frontal carina sharp and strongly developed .................................................................................. 18

17. Posterior pronotal margin not flanged, glabrous. Foretibia with moderately developed dorsal carina. Meso- and metatibia with transverse carina interrupted at middle ..................................................... ......................................................................................................... M. castanea ( Waterhouse, 1875)

– Posterior pronotal margin finely flanged and pubescent. Foretibia with developed dorsal carina. Meso- and metatibia with complete transverse carina ............................. M. hanoiensis Keith, 2006

18. Pronotal anterior margin without concavities at lateral ends .......................................................... 19

– Pronotal anterior margin with concavities at lateral ends................................................................ 22

19. Pronotal anterior margin glabrous. Epipleuron with long dense setae. Pygidium densely pubescent ........................................................................................................................................ 20

– Pronotal anterior margin with short pubescence. Epipleuron with setae except on apex. Pygidium with pubescence only on apex or, at most, with short and sparse pubescence on disk .................. 21

20. Pronotal lateral margins pubescent. Metatibia with transverse carina interrupted at middle ............. ............................................................................ M. siamensis Keith, 2004 (genital morphotype IX)

– Pronotal lateral margins glabrous. Metatibia with complete transverse carina .................................. ..................................................................... M. xingkei Gao & Fang, 2018 (genital morphotype IX)

21. Clypeus with anterior edge moderately emarginate. Mesotibia with transverse carina interrupted at middle ................................................................................... M. coromandeliana (Blanchard, 1850)

– Clypeus with anterior edge widely sinuous at middle. Mesotibia with transverse carina complete ....................................................................................................... M. excisa (Moser, 1913)

22. Pronotum with anterior margin pubescent ...................................................................................... 23

– Pronotum with anterior margin glabrous ........................................................................................ 27

23. Antennal club longer than funiculus; elytra with sparse long pubescence at humeral part ................ ...................................................................................................... M. recta Keith & Sabatinelli, 2010

– Antennal club shorter than funiculus; elytra without pubescence at humeral part ......................... 24

24. Clypeal anterior edge arcuate or moderately emarginate. Metatibia with complete transverse carina ............................................................................................................................................... 25

– Clypeal anterior edge widely wavy at middle. Metatibia with incomplete transverse carina ........ 26

25. Parameres with ventral branches thin. Characters from Gao et al. (2018)......................................... ...................................................................................................... M. tuberculipennis (Moser, 1913)

– Parameres with ventral branches thick and expanded. Characters from Gao et al. (2018)................ ......................................................................................................................... M. obscura Itoh, 1995

26. Pronotal posterior margin finely flanged. Frontal carina interrupted at middle .................................. ............................................................................................................... M. imitatrix ( Brenske, 1899)

– Pronotal posterior margin not flanged. Frontal carina continuous ...... M. abdominalis ( Hope, 1831)

27. Epipleuron of elytra partially pubescent ......................................................................................... 28

– Epipleuron of elytra with pubescence on full length ...................................................................... 29

28. Metatibia with complete transverse carina .......................................................... M. thai Keith, 2010

– Metatibia with interrupted transverse carina ....................................... M. diversiceps ( Moser, 1912)

29. Metatibia with complete transverse carina ..................................................................................... 30

– Metatibia with interrupted transverse carina ...................................................................................... .................................................................... M. ciliatipennis (Moser, 1903) (genital morphotype IX)

30. Dorsolateral margin of metatibia with one spine. Endophallus joined to temones at middle between proximal and distal ends. Dorsal branches of parameres bent downwards, apex curved inwards. Characters from Gao et al. (2018)..................................................... M. youweii Gao & Fang, 2018

– Dorsolateral margin of metatibia with two spines. Dorsal branches of parameres extended forwards. Endophallus joined to temones at proximal end. Characters from Gao et al. (2018)......................... ...................................................................................................... M. bannaensis Gao & Fang, 2018

31. Pronotal surface densely punctate (distance between punctures equal or smaller than diameter of puncture) (genital morphotypes III, IV, V and VII) ........................................................................ 32

– Pronotal surface scattered punctate (distance between punctures greater than diameter of puncture) (genital morphotypes II, VI and VIII) ............................................................................................. 46

32. Pronotal surface with strong and deep punctures and wrinkled appearance. Antennal club longer than funiculus or longer than stem (funiculus and scape) (genital morphotype VII) ..................... 33

– Pronotal surface with fine and superficial punctures, without wrinkled appearance. Antennal club as long as or shorter than funiculus (genital morphotypes III, IV, V).................................................. 34

33. Antennal club longer than funiculus. Pronotal posterior margin with tiny pubescence and a row of punctures. Metatibia with transverse carina interrupted at middle. Dorsal branch of parameres with a notch moderately developed at distal end ( Fig. 92B ) ........................ M. nigrescens ( Moser, 1916)

– Antennal club longer than stem (funiculus and scape). Pronotal posterior margin glabrous, and not flanged. Metatibia with transverse carina complete. Dorsal branch of parameres with a strong notch at distal end ( Fig. 18C ) ........................................................................ M. rugaticollis (Moser, 1913)

34. Meso- and metatibia without spines on inner margin of dorsal surface ......................................... 35

– Meso- and metatibiae with spines developed to a greater or lesser extent on inner margin of dorsal surface ............................................................................................................................................. 38

35. Mesotibia with transverse carina interrupted at middle .................................................................. 36

– Mesotibia with transverse carina complete ..................................................................................... 37

36. Clypeus with bidentate appearance, anterior edge deeply emarginate at middle. Frons with strong carina interrupted at middle. Pygidium without ornaments. Parameres with dorsal branch narrowing strongly toward caudal end; ventral branches with elevations at outer margin ( Fig. 9 ) ..................... ................................................................. M. bidentata ( Burmeister, 1855) (genital morphotype IV)

– Clypeus without bidentate appearance, anterior edge moderately emarginate at middle. Frons with strong carina complete. Pygidium depressed at middle or with ornaments. Parameres with dorsal branches very short, almost fused except by a groove ( Fig. 70 ) ........................................................ .......................................................................... M. dohrni (Brenske, 1894) (genital morphotype III)

37. Parameres with dorsal branch wide at full length; ventral branches shorter than dorsal one (Coca- Abia 2008: fig. 18) ............................................ M. longula ( Moser, 1912) (genital morphotype IV)

– Parameres with dorsal branch almost completely fused except at distal end; ventral branches much longer than dorsal ones ( Itoh 2002) .................... M. gravida ( Sharp, 1881) (genital morphotype III)

38. Parameres with dorsal and ventral branches completely ( Figs 12C , 85B ) or partially fused ( Keith 2020: figs 2–3, 5–6) by a membrane in lateral view; collum with a membranous area in dorsal view (genital morphotype V) ................................................................................................................... 39

– Parameres with dorsal and ventral branches separated at lateral view, without collum ................. 42

39. Pronotal posterior margin glabrous ................................................................................................. 40

– Pronotal posterior margin pubescent in front of scutellum .................. M. quasisinensis Keith, 2020

40. Parameres with dorsal and ventral branches completely ( Figs 12C , 85B ) fused in lateral view .... 41

– Parameres with dorsal and ventral branches partially fused (Keit, 2020: figs 5–6) by a membrane in lateral view ................................................................................................. M. axanensis Keith, 2020

41. Pronotum with anterior third of lateral margin not elevated. Parameres moderately curved downward, with two dorsal branches bilaterally asymmetrical ( Fig. 12A ) .................. M. sinensis ( Hope, 1842)

– Pronotum with anterior third of lateral margin moderately elevated. Parameres curved downward forty-five degrees, with two dorsal branches bilaterally symmetrical ( Fig. 85 ) ................................. ........................................................................................................... M. pseudosinensis Keith, 2010

42. Metatibia with transverse carina interrupted at middle .................................................................. 43

– Metatibia with transverse carina complete ..................................................................................... 44

43. Pronotal lateral margins moderately serrated and with few pubescence. Parameres with dorsal branch narrowing toward caudal end, with a rounded tip curving downward ............................................... ........................................................................... M. laosana ( Moser, 1912) (genital morphotype IV)

– Pronotal lateral margins smooth and without pubescence. Parameres with dorsal branches wrinkled at distal end and shorter than ventral ones .......................................................................................... ....................................................... M. leucophthalma ( Wiedemann, 1819) (genital morphotype III)

44. Clypeus with anterior edge strongly emarginate at middle, surface with lateral depressions. Pronotal lateral margins moderately serrated and with few pubescence. Dorsal branch of parameres narrowing towards distal end, with a rounded tip curving downward ( Fig. 75 ) .................................................. ..................................................................... M. saigonensis ( Moser, 1912) (genital morphotype IV)

– Clypeus with anterior edge emarginate at middle, without lateral depressions. Pronotal lateral margins smooth and without pubescence. Parameres with dorsal branch of different morphology ............ 45

45. Pronotal surface with non-confluent punctures (distance between punctures equal to diameter of puncture), with a bulge in each puncture. Dorsal branch of the parameres thin, with a rounded tip curving downward at caudal end ( Fig. 78 ) ............ M. vethi ( Moser, 1917) (genital morphotype IV)

– Pronotal surface with confluent punctures (distance between punctures smaller than diameter of puncture), without bulge in each puncture. Dorsal branch of parameres with a fan-shaped extension at caudal end ( Fig. 80 ) ................................ M. waterstradti ( Moser, 1912) (genital morphotype IV)

46. Metacoxa with whitish scales. Parameres with ventral branches joined each other, forming up a tubular structure (genital morphotype VI) ...................................................................................... 47

– Metacoxa with yellowish pubescence. Parameres with ventral branches separated each other, without forming up tubular structure (genital morphotype II, VIII) ............................................................ 48

47. Pronotal surface depressed behind anterior margin. Foretibia with strong carina. Metatibia with transverse carina complete, with spines on inner margin of dorsal surface. Parameres ( Fig. 15 ) ...... .............................................................................................................. M. borneensis ( Moser, 1918)

– Pronotal surface with regular appearance, without depression behind anterior margin. Foretibia with carina moderately developed. Metatibia with transverse carina interrupted at middle, without spines on inner dorsal margin. Parameres ( Fig. 89 ) .............................................. M. coxalis ( Arrow, 1944)

48. Meso- and metatibiae with two spines on inner margin of dorsal surface (genital morphotype II) ... ......................................................................................................................................................... 49

– Meso- and metatibia without spines on inner margin of dorsal surface (genital morphotype VIII) ................................................................................................................................................ 50

49. Foretibia with developed carina. Mesotibia with transverse carina complete .................................... ......................................................................................................................... M. herteli ( Frey, 1971)

– Foretibia with carina moderately developed. Mesotibia with transverse carina interrupted at middle ...................................................................................................................... M. gressitti ( Frey, 1970)

50. Pronotal surface irregularly and coarsely punctate. Parameres ( Fig. 96 ) ........................................... ............................................................................................................ M. schoolmeesteri Keith, 2010

– Pronotal surface regularly punctate and shiny. Parameres ( Fig. 20 ) ......... M. scutata ( Reitter, 1902)

Figures

Figs 90–93. 90. Miridiba rugaticollis (Moser, 1913), lectotype, ♂ (MFNB). Habitus in dorsal view. 91–93. M. nigrescens (Moser, 1916), lectotype, ♂ (MFNB). 91. Habitus in dorsal view. 92. Parameres in dorsal (A) and lateral (B) views. 93. Endophallus and temones in lateral view. Scale bars: 90–91 = 5.0 mm; 92–93 = 1.0 mm.

Figs 18–19. Morphotype VII “Rugaticollis”. Male genitalia of M. rugaticollis (Moser, 1913), lectotype (MFNB). 18. Parameres in dorsal (A), ventral (B) and lateral (C) views. 19. Endophallus and temones in lateral view. Scale bars = 1.0 mm.

Figs 9–11. Morphotype IV “Bidentata”. 9–10. Male genitalia of M. behrensi Brenske, 1892, lectotype (MFNB). 9. Parameres in dorsal (A), ventral (B) and lateral (C) views. 10. Endophallus and temones in ventral view. 11. Female genitalia of M. saigonensis (Moser, 1912),?syntype (MFNB) in dorsal (A) and ventral (B) views. Scale bars = 1.0 mm.

Figs 69–72. Miridiba dohrni (Brenske, 1894). 69–71. Lectotype, ♂ (MFNB). 72. Non-type, ♀ (MFNB). 69. Habitus in dorsal view.70. Parameres in dorsal (A), ventral (B) and lateral (C) views.71. Endophallus and temones in dorsal view. 72. Female genitalia, in dorsal view. Scale bars: 69 = 5.0 mm; 70–72 = 1.0 mm.

Figs 12–14. Morphotype V “Sinensis”. 12–13. Male genitalia of M. sinensis (Hope, 1842), lectotype (BMNH). 12. Parameres in dorsal (A), ventral (B) and lateral (C) views. 13. Endophallus and temones in ventral view. 14. Female genitalia of M. dalatensis Frey, 1970, holotype (NHMB) in lateral view. Scale bars = 1.0 mm.

Figs 83–86. 83. Miridiba sinensis (Hope, 1842), lectotype, ♂ (BMNH). Habitus in dorsal view. 84– 86. M. pseudosinensis Keith, 2010, holotype, ♂ (DKC). 84. Habitus in dorsal view. 85. Parameres in dorsal (A) and lateral (B) views. 86. Endophallus (everted) and temones in dorsal view. Scale bars: 83–84 = 5.0 mm; 85–86 = 1.0 mm.

Figs 73–76. 73. Miridiba behrensi Brenske, 1892, lectotype, ♂ (MFNB), habitus in dorsal view. 74– 76. M. saigonensis (Moser, 1912), lectotype, ♂ (MFNB). 74. Habitus in dorsal view. 75. Parameres in dorsal (A), ventral (B) and lateral (C) views. 76. Endophallus and temones in ventral view. Scale bars: 73–74 = 5.0 mm; 75–76 = 1.0 mm.

Figs 77–78. Miridiba vethi (Moser, 1917), lectotype, ♂ (MFNB). 77. Habitus in dorsal view. 78. Parameres in dorsal (A) and lateral (B) views. Scale bars: 77 = 5.0 mm; 78 = 1.0 mm.

Figs 79–82. Miridiba waterstradti (Moser, 1912). 79–81. Lectotype, ♂ (MFNB). 79. Habitus in dorsal view. 80. Parameres in dorsal (A), ventral (B) and lateral (C) views. 81. Endophallus and temones in dorsal view. 82. Paralectotype, ♀ (MFNB), genitalia in dorsal view. Scale bars: 79 = 5.0 mm; 80–82 = 1.0 mm.

Figs 15–17. Morphotype VI “Borneensis”. 15. Parameres of M. borneensis (Moser, 1918), lectotype (BMNH) in dorsal (A) and lateral (B) views. 16. Endophallus and temones of M. coxalis (Arrow, 1944), lectotype (BMNH) in dorsal view. 17. Female genitalia of M. coxalis, paralectotype (BMNH) in dorsal (A) and ventral (B) views. Scale bars = 1.0 mm.

Figs 87–89. 87. Miridiba borneensis (Moser, 1918), lectotype, ♂ (MFNB). Habitus in dorsal view. 88–89. M. coxalis (Arrow, 1944), lectotype, ♂ (BMNH). 88. Habitus in dorsal view. 89. Parameres in dorsal (A), ventral (B) and lateral (C) views. Scale bars: 87–88 = 5.0 mm; 89 = 1.0 mm.

Figs 94–97. 94. Miridiba scutata (Reitter, 1902), lectotype, ♂ (MFNB). Habitus in drosal view. 95– 97. M. schoolmeesteri Keith, 2010, holotype, ♂ (DKC). 95. Habitus in dorsal view. 96. Parameres in dorsal (A) and lateral (B) views. 97. Endophallus and temones in lateral view. Scale bars: 94–95 = 5.0 mm; 96–97 = 1.0 mm.

Figs 20–22. Morphotype VIII “Scutata”. 20. Male genitalia of M. scutata (Reitter, 1902), lectotype (MFNB), parameres in dorsal (A), ventral (B) and lateral (C) views. 21. Endophallus and temones of M. lassallei Keith, 2010, holotype (DKC) in lateral view. 22. Female genitalia of M. scutata, non-type (MFNB) in dorsal view. Scale bars = 1.0 mm.