Mesopolobus Westwood, 1833

Xiao, Hui, Sun, Lei, Jiao, Tianyang & Li, Zi, 2016, A revision of Chinese species of Mesopolobus Westwood (Hymenoptera: Pteromalidae) with descriptions of four new species from China, Zoological Systematics 41 (1), pp. 64-81 : 65-66

Mesopolobus Westwood, 1833

Mesopolobus Westwood, 1833: 443 . Type species: M. fasciiventris Westwood.

Mesopolobus Westwood : Rosen, 1958: 203–240; Graham, 1969: 638–681; Liao et al., 1987: 71; Bouček, 1988: 432–433; Baur et al., 2007: 387–397; Pujade, 1994: 63–73; Yang, 1996: 185–188.

Synonymy: Platymesopus Westwood, 1833: 444 ; Platyterma Walker, 1834a: 303 ; Amblymerus Walker, 1834a: 303 ; Eutelus Walker, 1834b: 351 ; Xenocrepis Förster, 1856: 64 ; Selitrichus Rondani, 1877: 196 ; Asemantus Förster, 1878: 51 ; Syntomocera Förster, 1878: 52 ; Disema Förster, 1878: 54 ; Zacalochlora Crawford, 1913: 251 ; Urielloides Girault, 1913: 106 ; Paranogmus Girault & Dodd, in Girault, 1915: 318 Anogmoidea Girault, 1924: 174 ; Baeoponerus Masi, 1924: 222 ; Euamblymerus Hincks, 1944: 37 ; Ahlbergiella Rosen, 1955: 88 ; Isoptrynea Szelényi, 1982: 381 ; Sturovia Bouček, 1961: 86 .

Diagnosis. Body green with luster; antenna 13-segmented, antennal formula 11353 or 11263; antennal insertion clearly below centre of face; right mandible 4-toothed and left mandible 3-toothed. Head occiput not margined; pronotum reticulate and posterior edge with conspicuous shiny strip, pronotal collar with abrupt edge but not carinate; notauli incomplete; scutellum without frenal line; propodeum usually with median carina complete, and plica developed or at least in posterior third, spiracles elongate; mesepisternum with upper triangular areas smooth; fore wing with speculum extending to marginal vein; costal cell on upper surface bare; gaster sessile.

Biology. Most species of the genus parasitize pupae of sawflies (Symphyta), Hymenoptera , Lepidoptera and Diptera . For example, M. mayetiolae (Gahan) lays eggs in pupa of Mayetiola destructor ( Gahan, 1933) , and M. subfumatus (Ratzeburg) attacks pupae of sawflies ( Kamijo, 1982). Some species develop as parasitoids in egg of host, such as M. superansi Yang & Gu was recorded from eggs of Dendrolimus superans (Butler) (Yang & Gu, 1995) , M. verditer (Noton) from eggs of Diprion simile ( Drooz et al., 1985) . Some species develop as ectoparasitoid, such as M. typographi (Ruschka) ectoparasitizing on Tomicobia seitneri (Ruschka) ( Graham, 1969) . Others develop as facultative hyperparasitism, such as M. subfumatus (Ratzeburg) , M. fagi Askew & Lamp , etc ( Noyes, 2014).

Distribution. Widespread in the world.

3.1 Key to the Chinese species of Mesopolobus Westwood, 1833

1. Marginal vein short, only 1.1–1.2 times as long as stigmal vein; lower face with striate or densely emgraved striate; gaster at most 2 times as long as broad ...................................................................................................................................................... M. albitarsus Marginal vein as least 1.4 times as long as stigmal vein; lower face reticulation.................................................................................2

2. Antennae inserted above lower ocular line; antennal toruli to clypeal margin slightly shorter than it to middle ocellus; pronotum with collar slightly margined................................................................................................................................................. M. aequus Antennae inserted below or at lower ocular line; antennal toruli to clypeal margin distinctly shorter than it to middle ocellus; pronotum with collar margined ............................................................................................................................................................3

3. Fore wing with basal cell hairy on 1/3–1/2 part ............................................................................................................ M. anogmoides Fore wing with basal cell bare or several hairs ....................................................................................................................................4

4. Antennae with 2 anelli and 6 funicular segments .................................................................................................................................5 Antennae with 3 anelli and 5 funicular segments .................................................................................................................................7

5. Postmarginal vein almost as long as marginal vein; basal cell hairy on 1/4–1/3 part.................... M. equivenae Sun & Xiao , sp. nov. Postmarginal vein shorter than marginal vein; basal cell bare.............................................................................................................. 6

6. Clypeal margin emarginate in the middle; malar area with white hairs in male................................................................ M. tortricidis Clypeal margin not emarginate; malar area without white hairs ........................................................................................... M. tibialis

7. Body small, nomally shorter than 1.5 mm, at most 1.5 mm ..................................................................................................................8 Body relatively big, at least bigger than 1.5 mm .................................................................................................................................. 9

8. Postmarginal vein at most as long as stigmal vein ........................................................................................................... M. keralensis Postmarginal vein distinctly longer than stigmal vein; male with a brown spot under stigmal vein ................................... M. minutus

9. Propodeum without medial carina...................................................................................................................................................... 10 Propodeum with distinctly medial carina ........................................................................................................................................... 11

10. Gaster oval, 1.6 times as long as broad ............................................................................................................................. M. superansi Gaster long, 2.95 times as long as broad .............................................................................................. M. changbaicus Xiao , sp. nov.

11. Clypeal margin emarginate and with two teeth .................................................................................................................................. 12 Clypeal margin truncate or sligtly emarginate, without tooth ............................................................................................................14

12. Pronotum with collar elongate, about 1/5–1/4 of mesoscutum in middle........................................................................... M. amaenus Pronotum with collar short, about 1/7–1/6 of mesoscutum in middle................................................................................................ 13

13. Scape reaching media occullus, as long as eye height......................................................................................................... M. semenis Scape not reaching media occellus, shorter than eye height...................................................................................... M. mesoeminulus

14. Propodeum with very roughly reticulation, media carina complete and plica distinct at half part; fore wing with a pale brown spot under stigmal vein......................................................................................................................................................... M. subfumatus Propodeum smooth on media part; others different ........................................................................................................................... 15

15. Fu 1 ring like, as long as the third anellus............................................................................................................................................16 Fu 1 distinct longer than the third anellus............................................................................................................................................ 17

16. Clava 1.75 times as long as broad; scape as long as eye height ........................................................................ M. tongi Xiao , sp. nov. Clava 1.6 times as long as broad; scape 0.89 times as long as eye height ......................................................................... M. teliformis

17. Gaster oval, 1.54 times as long as broad .......................................................................................................................... M. mesolatus Gaster long oval, at least 2 times as long as broad .............................................................................................................................18

18. Gaster 3 times as long as broad, and 1.2 times as long as head and thorax combined .............................................. M. rhabdophagae Gaster at most 2.7 times as long as broad, and as long as or shorter than head and thorax combined ............................................... 19

19. Pronotum with collar not margined.................................................................................................................................................... 20 Pronotum with collar margined ..........................................................................................................................................................21

20. Marginal vein 2.2 times as long as stigmal vein; gaster 2.3 times as long as broad; POL 2.16 times OOL ........................................... ................................................................................................................................................... M. beilingicus Sun & Xiao , sp. nov. Marginal vein 1.9 times as long as stigmal vein; gaster 2.5 times as long as broad; POL 2.83 times OOL ................... M. mongolicus

21. Scape slightly longer than eye height; marginal vein 1.68 times as long as stigmal vein...................................................... M. aspilus Scape distinctly shorter than eye height; marginal vein 1.8–2 times as long as stigmal vein .............................................................22

22. Propodeum with media carina only distinct at the basal part, plica complete .............................................................. M. agropyricola Propodeum with media carina and plica complete ............................................................................................................................. 23

23. Head width 2.17 times length in dorsal view; antennal insertion below lower ocular line.............................................. M. typographi Head width at most 2 times length in dorsal view; antennal insertion place on or slight higher lower ocular line ............................24

24. Gaster 2.6 times as long as broad; clava slightly clavate, 1.75 times as long as broad.......................................................... M. nobilis Gaster 2.37 times as long as broad; clava clavate distintly, 1.55 times as long as broad.................................................... M. prasinus