Exochus villosus Tolkanitz, 2003

Choi, Jin-Kyung, Kolarov, Janko & Lee, Jong-Wook, 2016, A taxonomic review of the genus Exochus Gravenhorst (Hymenoptera: Ichneumonidae: Metopiinae) from South Korea with descriptions of ten new species, Journal of Natural History 50, pp. 2327-2367 : 2360-2365

Exochus villosus Tolkanitz, 2003

( Figures 5g, n )

Exochus villosus Tolkanitz, 2003: 1075 – 1085 . Type: female; Type depository: ZI.

Specimens examined

( South Korea) 1 female, GW, Hongcheon-gun , Hongcheon-eup , Jangjeonpyeong 1-ri, Geomdungae village (M. T.), 37°39' N, 127°52' E, 1 – 20 June 2007, J .W. Lee ; 1 female, GW, Hongcheon-gun , Bukbang, Environment Research Park, 35°45'15.6" N, 127°51'1.7 “ E, 29 June – 16 July 2012, S .J. Jang .

Diagnosis

Female. Forewing 4.0 mm, body 4.0 mm long.

Face, mandible and malar space yellow ( Figure 5g ). Vertex without yellow spot. Antenna with 23 flagellomeres; ventral part of antenna yellowish brown and dorsal part of antenna dark blackish brown. Mesosoma black. Scutellum convex and black. Propodeum with lateromedian longitudinal carinae, without costula ( Figure 5n ); area basalis and area superomedia not separated by carina. Fore and mid legs yellow except basal part of coxae dark reddish brown. Hind leg yellow except coxa dark blackish brown. Vein Cu-a of forewing distad of vein Rs+M. Vein 2 rs-m shorter than vein between 2 rs-m and 2 m-cu. Vein cu-a of hindwing intercepted at lower part, vein Cu1 absent. Area between median longitudinal carinae of tergite 1 glabrous. Tergite 2 finely punctate. Epipleuron of third tergite wedge-shaped.

Distribution

South Korea (new record), Russia.

Key to species of the genus Exochus from South Korea

1. Epipleuron of third tergite wedge-shaped, basal three-quarters of the edge straight or weakly convex ( Figure 8a ). ..................................................................................................... 2

– Epipleuron of third tergite semicircular, basal three-quarters of the edge strongly convex ( Figure 8b ). ....................................................................................................................... 16

2. Vertex without yellow marks. Face and mandible yellow ( Figure 5g ) ............................. ............................................................................................................................ E. villosus Tolkanitz

– Vertex with triangular or other yellow marks at top of eyes ( Figure 8f ), or yellow triangular marks confluent with yellow inner orbits. Face and mandible yellow to black. ...................................................................................................................................................... 3

3. Mesosoma mostly yellow, with three black stripes on mesoscutum. Tergites 1 – 4 with brown band basally, tergites 5 – 7 brown. ............................ E. momoii Tolkanitz

– Mesosoma mostly black. Metasoma black. ........................................................................... 4

4. Yellow triangular marks and yellow inner orbits confluent ( Figure 8d ). Notaulus deep and distinct. Mesoscutum with square yellow mark, with spots at the anteriorly. Scutellum and postscutellum completely yellow. Propodeum with transverse area superomedia. ............................. ............................. E. areolalis Lee & Choi sp. nov.

– Yellow triangular marks and yellow inner orbits not confluent ( Figure 8e ). Notaulus absent or present but black. Mesoscutum black. Scutellum and postscutellum black or yellow. Propodeum with or without area superomedia, if present as wide as long or longer than width. ..................................................................................................................... 5

5. Antenna with fewer than 23 flagellomeres. Face and mandible completely yellow.. ........................................................... ......................................................... E. selenanae Tolkanitz

– Antenna with more than 23 flagellomeres. Face and mandible black and yellow (at least clypeus black). ......................................................................................................................... 6

6. Inner margins of eyes ventrally convergent. Antenna with fewer than 25 flagello- meres. .................................................................................... E. orbitalis Lee & Choi sp. nov.

– Inner margins of eyes subparallel. Antenna with more than 29 flagellomeres. .......... 7

7. Antennal scape, scutellum and postscutellum partly yellowish brown. Hind tibia yellow with apical black band. ............................. ............................. E. vexator Tolkanitz

– Antennal scape almost dark brown. Scutellum and postscutellum completely black. Hind tibia yellow to brown without black band apically. .............................................. 8

8. Forewing vein cu-a opposite rs+m. ( Figure 8g ). ................................................................. 9

– Forewing vein cu-a distad distad of Rs+M. ( Figure 8h ). ............................................... 13

9. Body length less than 6 mm. Vertex with small yellow spot at apex of inner orbit (spot circular, of similar size to ocellus) ................ ................ E. kusigematii Tolkanitz

– Body length more than 6 mm. Vertex with triangular yellow marks on apex of eyes orbit. .................................................................................................................................................... 10

10. Area superomedia and area basalis separated by transverse carina ( Figure 7a ). Face yellow and black (at least inter-antennal projection yellow). .................................... 11

– Area superomedia and area basalis not separated by transverse carina ( Figure 7h ). Face black. ........................................................................................................................................ 12

11. Pronotum matt and sparsely punctate. Basal transverse carina of propodeum medially incomplete ( Figure 7e ). ................. ................. E. flavomarginatus Holmgren

– Pronotum glabrous. Basal transverse carina of propodeum complete ( Figure 7a ). Face black and angular projection between antennal sockets yellow ( Figure 4a ). ... ........................................................................................................................... E. argutus Tolkanitz

12. Frons flat, not concave, between antennal sockets without longitudinal ridge. ........ ............................................................... E. nigrifaciatus Momoi, Kusigemati & Nakanishi

– Frons convex, between antennal sockets with longitudinal ridge. ................................... ............................................................................................................... E. gravipes (Gravenhorst)

13. Body longer than 8 mm. Antenna with more than 36 flagellomeres. Propodeum with full areolation ( Figure 6d ). .................................. E. carinalis Lee & Choi sp. nov.

– Body shorter than 7 mm. Antenna with fewer than 32 flagellomeres. Propodeum without full areolation (at least area basalis and area superomedia not separated by carina) .......................................................................................................................................... 14

14. Vein cu-a of hindwing almost not intercepted, vein Cu1 vestigial. Tergite 1 with strong lateral carina and strong angle basally in lateral view. .. E. antis Tolkanitz

– Vein cu-a of hindwing intercepted lower 0.3, vein Cu1 present. Tergite 1 with weak lateral carina and round in lateral view. ............................................................................. 15

15. All coxae black. Propodeum with costula; area petiolaris setose and area posteroexterna depressed. .......................................................................... E. consimilis Holmgren

– All coxae reddish brown. Propodeum without costula; area petiolaris hairless and area posteroexterna not depressed. .................. E. acostulatus Lee & Choi sp. nov.

16. Vertex black, without yellow triangular spots; face, malar space and antennal scape black in frontal view. ...................................................... E.nigritulus Lee & Choi sp. nov.

– Vertex black, with yellow triangular spots or with yellow continuous from inner orbit to vertex; face, malar space and antennal scape yellow and black in frontal view ..................................................................................................................................................... 17

17. Yellow triangular marks and yellow inner orbits confluent. Upper margin of pronotum with yellow line .............................................................................................................. 18

– Yellow triangular marks and yellow inner orbits not confluent. Pronotum completely black or with yellow spot on upper right corner. ................................................. 24

18. Area superomedia and area basalis of propodeum separated by transverse carina, area superomedia longer than wide. Vein Cu1 of hindwing absent.. .... ....................... ...................................................................................................................... E. frontellus Holmgren

– Area superomedia and area basalis of propodeum not separated by transverse carina. Vein Cu1 of hindwing present or vestigial. ......................................................... 19

19. Lower tooth of mandible indistinct ( Figure 8i ). Mesopleuron with yellow lines. ....... ................................................................................................ E. adentatus Lee & Choi sp. nov.

– Lower tooth of mandible distinct ( Figure 8j ). Mesopleuron with yellow spot, sometimes with thin yellow line on upper margin of mesopleuron. ............................... 20

20. Antenna with fewer than 23 flagellomeres. Body shorter than 4 mm. Propodeum without apical transverse carina. .................................................. E. destitutus Tolkanitz

– Antenna with more than 30 flagellomeres. Body longer than 5 mm. Propodeum with apical transverse carina. ................................................................................................... 21

21. Clypeus black. Mesopleuron completely black. Area superomedia and area dentipara rectangular, longer than wide in dorsal view. ....................................................... 22

– Clypeus yellow. Mesopleuron black with yellow spot on anterior part. Area superomedia and area dentipara square or wider than long in dorsal view. ............... 23

22. Fore and mid coxae of same colour. Median longitudinal areas of tergites 1 – 2 glabrous, width of median longitudinal area of tergite 1 as wide as median longitudinal area of tergite 2 ................................. ................................. E. lineifrons Thomson

– Fore coxa darker than mid coxa. Median longitudinal areas of tergites 1 – 2 glabrous, width of median longitudinal area of tergite 1 wider than median longitudinal area of tergite 2... .................................................... E. semilividus Vollenhoven

23. Upper face pale yellow and lower face black ( Figure 4j ). All legs yellow without black bands. Vein cu-a of hindwing intercepted at lower 0.25, vein Cu1 present. Body length 5.5 – 6 mm. .................................................................................. E. lictor Haliday

– Face mostly yellow with blackish brown shield mark on central part of face ( Figure 4i ). Legs yellow, hind tibia with black bands basally and apically. Vein cu- a of hindwing intercepted at lower 0.1, vein Cu1 absent. Body length 7 – 7.5 mm. .. ......................................................................................................................... E. guttatus Tolkanitz

24. Interantennal process of upper face very strong (recurved projection, almost reaching frons) ( Figure 8k ). Metasoma coarsely, densely punctate and matt. ........................ ................................................................................................................... E. mitratus Gravenhorst

– Interantennal process of upper face not so strong (projection not reaching frons) ( Figure 8l ). Metasoma sparsely punctate and polished. ............................................... 25

25. Propodeal carinae almost absent, apical transverse carina weak ( Figure 6j ) ............... ............................................................................................ E. propodealis Lee & Choi sp. nov.

– Propodeal carinae present, at least apical transverse carina distinct. .................... 26

26. Costula of propodeum absent. All coxae dark blackish brown to black. ............. 27

– Cotula of propodeum present. All coxae reddish brown. ........................................... 28

27. Frons and area of ocelli strongly convex. Mesoscutum strongly depressed and notaulus deep ( Figure 8m ). Vein 2 rs-m shorter than vein between 2 rs-m and 2 m-cu. Antenna with 24 flagellomeres .............. E. depressus Lee & Choi sp. nov.

– Frons weakly convex and area of ocelli flat. Mesoscutum not depressed, convex in lateral view ( Figure 8n ). Vein 2 rs-m as long as vein between 2 rs-m and 2 m-cu. Antenna with 20 flagellomeres. ............................................................ E. gratus Tolkanitz

28. Face and clypeus completely yellow. .................................................................................... 29

– Face mostly black, projection with yellow marks partly; clypeus black. ............... 30

29. Metasoma finely punctate. Scutellum and postscutellum partly yellow. Antenna with 28 flagellomeres. Body length 6 mm. ............................ E. alpinus (Zetterstedt)

– Metasoma coarsely punctate. Scutellum and postscutellum black. Antenna with 23 flagellomeres. Body length 5 mm. .......................... .......................... E. velatus Tolkanitz

30. Occipital carina absent. .............................................. E. occipitalis Lee & Choi sp. nov.

– Occipital carina complete. ......................................................................................................... 31

31. Mesosternum projecting backward as a couple of teeth ( Figure 8c ). Antenna with 24 flagellomeres .......................... .......................... E. dentisternum Lee & Choi sp. nov.

– Mesosternum without projections. Antenna with more than 32 flagellomeres 32

32. Face mostly black, malar space black. Scutellum and postscutellum black. Lateral carinae of area superomedia subparallel. Antenna with 34 flagellomeres. ................... ....................................................................................................................... E. ventralis Holmgren

– Face black with yellow marks, malar space yellow. Scutellum and postscutellum yellow. Lateral carinae of area superomedia posteriorly convergent. Antenna with more than 38 flagellomeres. .................................................................................................... 33

33. Body sparsely pilose and polished. Epicnemium of mesosoma with yellow spot. Metasoma dark reddish brown with brown apical line and polished. Hindwing with seven distal hamuli. .............................................................................. E. britannicus Morley

– Body densely pilose. Epicnemium of mesosoma without yellow spot. Metasoma black. Hindwing with eight distal hamuli. .......................................................................... 34

34. Median longitudinal carinae of tergite 1 reaching middle of tergite. Area between longitudinal carinae of tergite 1 matt; tergite 1 with scattered punctures. .................. ................................................................................................... E. suborbitalis Schmiedeknecht

– Median longitudinal carinae of tergite 1 not reaching middle of tergite. Area between longitudinal carinae glabrous. ...................... E. thomsoni Schmiedeknecht

Figures

Figure 4. Head in frontal view. (a) Exochus argutus; (b) Exochus britannicus; (c) Exochus consimilis; (d) Exochus destitutus; (e) Exochus flavomarginatus; (f) Exochus frontellus; (g) Exochus gratus; (h) Exochus gravipes; (i) Exochus guttatus; (j) Exochus lictor; (k) Exochus lineifrons; (l) Exochus mitratus. Scale bar = 0.2 m m.

Figure 5. Head in frontal view. (a) Exochus momoii; (b) Exochus nigrifaciatus; (c) Exochus selenanae; (d) Exochus velatus; (e) Exochus ventralis; (f) Exochus vexator; (g) Exochus villosus; (h) Exochus momoii; (i) Exochus nigrifaciatus; (j) Exochus selenanae; (k) Exochus velatus; (l) Exochus ventralis; (m) Exochus vexator; (n) Exochus villosus. Scale bar = 0.2 mm.

Figure 6. Propodeum in dorsal view. (a) Exochus acostulatus Lee & Choi, sp. nov.; (b) Exochus adentatus Lee & Choi, sp. nov.; (c) Exochus areolaris Lee & Choi, sp. nov.; (d) Exochus carinalis Lee & Choi, sp. nov.; (e) Exochus dentisternum Lee & Choi, sp. nov.; (f) Exochus depressus Lee & Choi, sp. nov.; (g) Exochus nigritulus Lee & Choi, sp. nov.; (h) Exochus occipitalis Lee & Choi, sp. nov.; (i) Exochus orbitalis Lee & Choi, sp. nov.; (j) Exochus propodealis Lee & Choi, sp. nov.; (k) Exochus alpinus; (l) Exochus antis. Scale bar = 0.2 mm.

Figure 7. Propodeum in dorsal view. (a) Exochus argutus; (b) Exochus britannicus; (c) Exochus consimilis; (d) Exochus destitutus; (e) Exochus flavomarginatus; (f) Exochus frontellus; (g) Exochus gratus; (h) Exochus gravipes; (i) Exochus guttatus; (j) Exochus lictor; (k) Exochus lineifrons; (l) Exochus mitratus. Scale bar = 0.2 m m.

Figure 8. Morphological characters. (a) Third epipleuron of Exochus nigrifaciatus; (b) third epipleuron of Exochus ventralis; (c) Projection of mesosternum in Exochus dentisternum; (d) Frons of Exochus areolalis; (e) Frons of Exochus alpinus; (f) Frons of Exochus fravomarginatus; (g) Vein Cu-a of Exochus fravomarginatus; (h) Vein Cu-a of Exochus consimilis; (i) Mandible of Exochus adentatus; (j) Mandible of Exochus guttatus; (k) Interantennal process of Exochus mitratus; (l) Interantennal process of Exochus propodealis; (m) Mesoscutum of Exochus depressus; (n) Mesoscutum of Exochus gratus. Scale bars: (a–f), (i–n) = 0.2 mm; (g, h) = 0.5 mm.