Scymnus

Nestor-Arriola, Jorge I., Clark, Shawn M. & Niño-Maldonado, Santiago, 2022, Taxonomic and Distributional Notes on the Genus Scymnus Kugelann, 1794 (Coleoptera: Coccinellidae) in Mexico, The Coleopterists Bulletin 76 (3), pp. 299-328 : 301-304

KEY TO SPECIES OF SCYMNUS OF MEXICO

1. Pronotum yellow, red, orange, ocher or pale brown ( Fig. 4 ) .............................. 2

1′. Pronotum black or dark brown, or at least with black basal spot ( Figs. 1, 2, 3 , 40 ) .... 7

2(1). Elytra totally or mainly yellow, ocher or pale brown ( Figs. 1, 4 ) ......................... 3

2′. Elytra totally or mainly black or dark brown ( Figs. 2, 3 , 40 ) ........................... 5

3(2). Body oval with parallel sides. Penis guide of male genitalia with hook-shaped ventral projections ( Figs. 16, 17 ) ......................... ................................... S. enochrus Gordon

3′. Body shape and male genitalia different from above ........................................... 4

4(3). Penis guide of male genitalia with acute apex; remainder of lobe with lateral expanded margins; parameres slightly longer than half penis guide ( Figs. 37, 38 ) ........ ..................................... S. trulla Gordon

4′. Penis guide of male genitalia with lateral alae; parameres short and wide (for more information see Gordon 1976) ................ ................................... S. nugator Casey

5(2). Male genitalia with penis guide expanded laterally, except at apex ( Fig. 11 ) ............ .............................. S. cerinotum Gordon

5′. Male genitalia different from above .... 6

6(5). Male genitalia with narrow parameres; apex of penis guide not elongate beyond parameres ( Figs. 5, 6 ) ............................. ................................. S. kansanus Casey

6′. Male genitalia with wide and heavily sclerotized parameres; penis guide with elongate acute apex ( Figs. 13, 14 ) ................. ............................. S. cervicalis Mulsant

7(1). Elytra reddish brown ( Fig. 58 ); males with spine-like process at metaventral apex ( Fig. 57 ); male genitalia with wide, heavily sclerotized lateral alae fused with penis guide ( Figs. 55 , 61 ); penis robust with spines at apex ( Figs. 56 , 62 ) ................... ........................ S. erwini Nestor-Arriola and Niño-Maldonado , new species

7′. Male genitalia different than described above .................................................... 8

8(7). Penis guide of male genitalia without lateral alae ............................................ 9

8′. Penis guide of male genitalia with lateral alae ..................................................... 18

9(8). Penis guide of male genitalia without membranous projections ............................ 10

9′. Penis guide of male genitalia with membranous projections ............................ 17

10(9). Males with medial tubercle on first ventrite, near posterior margin (for detailed information see Gordon 1976) ................ ............... S. marginicollis Mannerheim

10′. Males without tubercle on first ventrite .......................................... 11

11(10). Penis guide of male genitalia as wide as long .................................................... 12

11′. Penis guide of male genitalia longer than wide .................................................... 14

12(11). Color variable, usually dark brown except pronotal margins and apical spot on each elytron; elytral spot sometimes reaching humeral callus, reddish brown to yellowish brown; parameres without dorsal projection; penis narrow ( Figs. 25, 27 ) ............. ................................... S. loewii Mulsant

12′. Color dorsally black, except pronotum red, orange or yellow with dark basal macula, and apical fifth of elytra red, orange or yellow; parameres with dorsal projection; penis robust ........................................ 13

13(12). Apical half of penis with almost parallel sides ( Fig. 30 ) ..... S. louisianae Chapin

13′. Apical half of penis not parallel-sided ( Fig. 21 ) .......................... S. fraternus Wingo

14(11). Penis guide of male genitalia with margins expanded laterally; parameres short and wide ( Fig. 11 ) ...... S. cerinotum Gordon

14′. Penis guide of male genitalia with margins not expanded laterally; parameres long and narrow ................................................ 15

15(14). Penis guide of male genitalia with apical fourth narrow and with dorsal barb; rest of lobe with almost parallel sides ( Fig. 35 ) ..................... S. rohdendorfi Ukrainsky

15′. Penis guide of male genitalia without abruptly narrowed apex or dorsal barb .................................................... 16

16(15). Penis guide of male genitalia with sinuate lateral margins, narrowing before apical third ( Fig. 32 ) ....... S. pulvinatus Wingo

16′. Penis guide of male genitalia with slightly curved sides; ventral process hardly pronounced, with straight superior margin ( Figs. 8, 9 ) .............. S. pacificus Crotch

17(9). Penis guide of male genitalia subtriangular; parameres wide, almost as long as penis guide; lateral membranous projection of penis guide with rounded apex ( Figs. 22, 23 ) ................. S. gilae Casey

17′. Penis guide of male genitalia with acute, elongate apex; lateral membranous projections sinuous ( Figs. 42, 43 , 45, 46 ) ......... ....................... S. zuritai Nestor-Arriola and Niño-Maldonado , new species

18(8). Penis guide of male genitalia without membranous projections ............................ 19

18′. Penis guide of male genitalia with membranous projections ............................ 28

19(18). Penis guide of male genitalia with heavily sclerotized lateral alae covering lobe in ventral view ( Figs. 51, 52 ) ...................... .................................. S. bryanti Gordon

19′. Lateral alae of penis guide with variable sclerotization, not covering lobe in ventral view .................................................... 20

20(19). Lateral alae fused to penis guide for more than half their distance ....................... 21

20′. Lateral alae free or fused with penis guide only in their basal half ....................... 26

21(20). Apex of penis guide of male genitalia free ..................................................... 22

21′. Apex of penis guide of male genitalia fused with lateral alae .................................. 25

22(21). Parameres as long as penis guide ....... 23

22′. Parameres shorter than penis guide ....... 24

23(22). Apex of penis guide of male genitalia abruptly narrowed in apical fourth and with a dorsal hook ( Fig. 81 ) .................... ............................ S. simillimus Gordon

23′. Apex of penis guide of male genitalia acute, but not abruptly narrowed, without dorsal hook ( Figs. 78, 79 ) ........................ .................................... S. impletus Gordon

24(22). Apex of penis guide of male genitalia acute (for detailed information see Gordon 1976) .................. S. tenebricus Gordon

24′. Apex of penis guide of male genitalia rounded (for detailed information see Gordon 2000) ........... S. dozieri Gordon

25(21). Penis guide of male genitalia slightly longer than lateral alae and with truncate apex; alae with truncate apex (for more information see Gordon 1976) ............................ .............................. S. caudalis LeConte

25′. Penis guide of male genitalia longer than lateral alae, rounded at apex; lateral alae with oblique apex (for more information see Gordon 1976). S. creperus Mulsant

26(20). Penis guide of male genitalia with dorsal and ventral processes undifferentiated ( Fig. 63 ) .................... S. horni Gorham

26′. Penis guide of male genitalia with dorsal and ventral processes differentiated ....... 27

27(26). Ventral process of penis guide of male genitalia longer than dorsal process ( Fig. 76 ) ................................. S. ignarus Gordon

27′. Ventral process of penis guide of male genitalia equal in length with dorsal process; dorsal process wide (for detailed information see Gordon 1976) ............................ ............................... S. tenebrosus Casey

28(18). Apex of penis guide of male genitalia rounded in lateral view ( Fig. 69 ) ............ ............................. S. huachuca Gordon

28′. Apex of penis guide of male genitalia acute in lateral view ( Fig. 72 ) ..................... 29

29(28). Penis with trifurcate apex clearly wider than rest of penis ( Fig. 74 ) ...................... .............................. S. hubbardi Gordon

29′. Penis with trifurcate apex only slightly wider than rest of penis ...................... 30

30(29). Tegmen wide ( Fig. 67 ) ............................ ............................... S. howdeni Gordon

30′. Tegmen narrow ( Fig. 49 ) ........................ ................................... S. brullei Mulsant

Figures

Figs. 1–4. Scymnus spp., dorsal habitus. 1) S. pacificus; 2) S. pulvinatus; 3) S. fraternus; 4) S. trulla. Scale bars: 2.0 mm.

Figs. 40–44. Scymnus (Pullus) zuritai, new species. 40) Dorsal habitus; 41) Abdomen; 42) Tegmen, lateral view;

Figs. 16–21. Scymnus spp., male genitalia (figures are not to same scale). S. enochrus: 16) Tegmen, lateral view; 17) Tegmen, ventral view; 18) Penis. S. fraternus: 19) Tegmen, lateral view; 20) Tegmen, ventral view; 21) Penis.

Figs. 34–39. Scymnus spp., male genitalia (figures are not to same scale). S. rohdendorfi: 34) Tegmen, lateral view;

Figs. 11–15. Scymnus spp., male genitalia (figures are not to same scale). S. cerinotum: 11) Tegmen, ventral view;

Figs. 5–10. Scymnus spp., male genitalia (figures are not to same scale). S. kansanus: 5) Tegmen, lateral view;

Figs. 57–62. Scymnus (Pullus) erwini, new species. 57) Metaventral spiniform process; 58) Dorsal habitus; 59) Abdomen; 60) Tegmen, lateral view; 61) Tegmen, ventral view; 62) Penis. Scale bar for 57–59: 2.0 mm; for 60–62: 1.0 mm.

Figs. 51–56. Scymnus spp., male genitalia (figures are not to same scale). S. bryanti: 51) Tegmen, lateral view; 52) Tegmen, dorsal view; 53) Penis. S. erwini, new species: 54) Tegmen, lateral view; 55) Tegmen, ventral view; 56) Penis.

Figs. 22–27. Scymnus spp., male genitalia (figures are not to same scale). S. gilae: 22) Tegmen, lateral view;

Figs. 28–33. Scymnus spp., male genitalia (figures are not to same scale). S. louisianae: 28) Tegmen, lateral view;

Figs. 45–50. Scymnus spp., male genitalia (figures are not to same scale).S.zuritai, new species: 45) Tegmen, lateral view;

Figs. 81–83. Scymnus simillimus, male genitalia (figures are not to same scale). 81) Tegmen, lateral view;

Figs. 75–80. Scymnus spp., male genitalia (figures are not to same scale). S. ignarus: 75) Tegmen, lateral view;

Figs. 63–68. Scymnus spp., male genitalia (figures are not to same scale). S. horni: 63) Tegmen, lateral view; 64) Tegmen, ventral view; 65) Penis. S. howdeni: 66) Tegmen, lateral view; 67) Tegmen, ventral view; 68) Penis.

Figs. 69–74. Scymnus spp., male genitalia (figures are not to same scale). S. huachuca: 69) Tegmen, lateral view; 70) Tegmen, ventral view; 71) Penis. S. hubbardi: 72) Tegmen, lateral view; 73) Tegmen, ventral view; 74) Penis.