Merostenus

Gibson, Gary A. P., 2017, Synonymy of Reikosiella Yoshimoto under Merostenus Walker (Hymenoptera: Chalcidoidea: Eupelmidae), with a checklist of world species and a revision of those species with brachypterous females, Zootaxa 4255 (1), pp. 1-65 : 21-22

publication ID	https://doi.org/ 10.5281/zenodo.556479
publication LSID	lsid:zoobank.org:pub:3EF97DA3-EF37-4D91-8689-2AB9151D1440
DOI	https://doi.org/10.5281/zenodo.6049189
persistent identifier	https://treatment.plazi.org/id/03C187CB-2278-CF30-FF78-FA33FA204FCD
treatment provided by	Plazi
scientific name	Merostenus
status

Treatment

Key to species of Merostenus View in CoL View at ENA with brachypterous females

1 Female..............................................................................................2

- Male............................................................................................... 11

2(1) Mesosoma in lateral view with apex of scutellum protuberant over underlying dorsellum ( Fig. 132 View FIGURES 124 – 133 ) and in dorsal view propodeum with transverse carina dividing anterior concave portion under apex of scutellum from posterior portion behind scutellar apex ( Fig. 131 View FIGURES 124 – 133 ); mesotibia with patch of strong spines apically over base of mesotarsus but not row of pegs; head green and meso- and metasoma yellowish to orange with some brown markings ( Figs 125, 126 View FIGURES 124 – 133 ); outer surface of metacoxa entirely and about ventral half of metapleuron setose ( Fig. 132 View FIGURES 124 – 133 )..................... Merostenus (Reikosiella) melinus (Yoshimoto)

- Mesosoma in lateral view with dorsellum subvertical, cuplike over apex of scutellum and in dorsal view propodeum variable in structure but without transverse carina dividing plical region into anterior and posterior portions; mesotibia with variable number of pegs in row apically over base of mesotarsus; other features variable, but not in combination......3 [M. ( Merostenus View in CoL )]

3(2) Pronotum divided medially ( Figs 26 View FIGURES 22 – 30 , 60 View FIGURES 56 – 65 )...................................................................4

- Pronotum uniformly sclerotized ( Figs 33 View FIGURES 31 – 38 , 41 View FIGURES 39 – 48 , 86 View FIGURES 83 – 89 , 93 View FIGURES 90 – 97 , 100 View FIGURES 98 – 105 ) even if sometimes with paler line mediolongitudinally ( Fig. 41 View FIGURES 39 – 48 ) or short mediolongitudinal furrow posteriorly ( Fig. 100 View FIGURES 98 – 105 : arrow)..............................5 [ excavatus View in CoL species-group]

4(3) Flagellum with at least fl3 and fl4 white, and fl5 somewhat lighter yellowish-brown in contrast to other darker brown flagellomeres ( Figs 22, 24 View FIGURES 22 – 30 ); ovipositor sheaths short and rigid, exserted beyond syntergum by only about one-fifth length of gaster ( Fig. 29 View FIGURES 22 – 30 ); scutellar-axillar complex longitudinally strigose without large depression between axillae anterior to scutellum ( Figs 26, 28 View FIGURES 22 – 30 ); fore wing slender and tapered to angulate apex ( Fig. 28 View FIGURES 22 – 30 ); propodeum with posterior margin widely separated from anterior margin and with median carina ( Fig. 28 View FIGURES 22 – 30 )............................ M. (Merostenus) congoensis n. sp.

- Flagellum entirely dark ( Fig. 59 View FIGURES 56 – 65 ); ovipositor sheaths long and filamentous, exserted beyond syntergum for distance at least equal to length of gaster ( Fig. 58 View FIGURES 56 – 65 ); scutellar-axillar complex meshlike coriaceous to coriaceous-imbricate and with large depression between axillae anterior to scutellum ( Figs 61, 63 View FIGURES 56 – 65 ); fore wing spatulate with broadly rounded apical margin ( Figs 61, 63 View FIGURES 56 – 65 ); propodeum with posterior margin incurved to anterior margin medially ( Fig. 61 View FIGURES 56 – 65 )....................................................................................................... M. (Merostenus) longistylus n. sp.

5(3) Antenna with scape to fl2 yellowish ( Fig. 77 View FIGURES 74 – 82 ); fore wing right-angle bent with about basal half of disc membranous and apical half consisting only of dark, linear venation ( Fig. 77 View FIGURES 74 – 82 : insert); propodeum strongly transverse with narrow plical region deeply concave on either side of high median carina and mesal to convex callar regions ( Fig. 79 View FIGURES 74 – 82 ); scutellar-axillar complex with each axilla almost flat except for indistinct mediolongitudinal carina ( Figs 78, 79 View FIGURES 74 – 82 ); syntergum recurved apically as posteriorly rounded syntergal flange ( Figs 75, 81 View FIGURES 74 – 82 ) [New World]............................... M. (Merostenus) mexicanus n. sp.

- Antenna sometimes with scape and pedicel yellowish but flagellum dark; fore wing flat over body and disc membranous to apex; propodeum variable, but if similar to above then axillae longitudinally striate-strigose; syntergum flat with posterior margin transverse [Old World]........................................................................... 6

6(5) Scutellar-axillar complex with each axilla at least as large as scutellum and longitudinally striate-strigose ( Fig. 43 View FIGURES 39 – 48 ); propodeum ( Fig. 43 View FIGURES 39 – 48 ) with posterior margin sinuately incurved almost to anterior margin such that medial margins contiguous over much of length and curved up to form high median carina and forming narrow plical region between cone-like protuberant callar regions ( Figs 43, 44 View FIGURES 39 – 48 ); fore wing with disc short-spatulate, only slightly longer than wide and extending only to about level of anterior margin of scutellar frenum ( Fig. 43 View FIGURES 39 – 48 ); antenna with scape yellow ( Figs 39, 42 View FIGURES 39 – 48 ) [Palaearctic]............................................................................................ M. (Merostenus) excavatus (Dalman) View in CoL

- Scutellar-axillar complex with each axilla much smaller than scutellum and smooth to finely coriaceous; propodeum with posterior margin distant from anterior margin, only shallowly, Π-like incurved, and broad plical region with median carina in almost same plane as callar regions; fore wing usually with disc elongate-spatulate, much longer than wide and extending to base of gaster; antenna sometimes with scape dark [Afrotropical]................................................ 7

7(6) Antenna with scape foliaceously compressed and flagellum robust-clavate with all funiculars strongly transverse ( Figs 90–92 View FIGURES 90 – 97 ); metapleuron bare (not to be confused with ventral setose region between acropleuron and meso- and metacoxae, Fig. 95 View FIGURES 90 – 97 ); scutellar-axillar complex with scutellum carinate anteriorly between longitudinally carinate axillae ( Fig. 94 View FIGURES 90 – 97 )...................................................................................... M. (Merostenus) platyscapus n. sp.

- Antenna with scape slender and flagellum gracile-clavate with all or most funiculars quadrate to longer than wide ( Figs 34 View FIGURES 31 – 38 , 85 View FIGURES 83 – 89 , 101 View FIGURES 98 – 105 , 117 View FIGURES 115 – 123 ); metapleuron mostly setose ( Figs 35 View FIGURES 31 – 38 , 88 View FIGURES 83 – 89 , 102 View FIGURES 98 – 105 , 120 View FIGURES 115 – 123 ); scutellar-axillar complex with scutellum uniformly convex and oval, and axillae not distinctly carinate ( Figs 36 View FIGURES 31 – 38 , 87 View FIGURES 83 – 89 , 103 View FIGURES 98 – 105 , 119 View FIGURES 115 – 123 )..................................................8

8(7) Fore wing extending only to about level of posterior margin of propodeal spiracle ( Fig. 87 View FIGURES 83 – 89 ); head with frons ( Fig. 83 View FIGURES 83 – 89 ) and mesoscutum ( Fig. 86 View FIGURES 83 – 89 ) smooth and shiny; scrobal depression shallow and high O-like, about as high as wide ( Fig. 83 View FIGURES 83 – 89 ).............................................................................. M. (Merostenus) micropterus n. sp.

- Fore wing extending to base of gaster ( Figs 36 View FIGURES 31 – 38 , 103 View FIGURES 98 – 105 ); head either with frons and mesoscutum coriaceous to reticulate ( Figs 31 View FIGURES 31 – 38 , 98 View FIGURES 98 – 105 ) or scrobal depression distinctly concave and transversely Π-like ( Fig. 115 View FIGURES 115 – 123 )..................................... 9

9(8) Mesoscutum with subcircular pit on lateral lobe near mid-length ( Fig. 33 View FIGURES 31 – 38 : arrows); head with frons finely coriaceous between scrobal depression and anterior ocellus ( Fig. 31 View FIGURES 31 – 38 ); mesoscutum coriaceous ( Fig. 33 View FIGURES 31 – 38 ); body mostly dark brown, including entire gaster ( Figs 32, 34 View FIGURES 31 – 38 )........................................................... M. (Merostenus) distigma n. sp.

- Mesoscutum uniformly sclerotized without pits; head and mesoscutum either smooth and shiny or more strongly reticulate than above; body extensively orangish to orangish-brown, including basal two gastral tergites........................10

10(9) Head with face ( Fig. 98 View FIGURES 98 – 105 ), mesoscutum ( Fig. 100 View FIGURES 98 – 105 ) and most of gaster ( Fig. 104 View FIGURES 98 – 105 ) strongly reticulate; scrobal depression shallow and high Π-like, about as high as wide ( Fig. 98 View FIGURES 98 – 105 ).................................. M. (Merostenus) reticulatus n. sp.

- Head between scrobal depression and anterior ocellus ( Fig. 115 View FIGURES 115 – 123 ), mesoscutum ( Fig. 118 View FIGURES 115 – 123 ) and gaster ( Fig. 121 View FIGURES 115 – 123 ) smooth and shiny; scrobal depression distinctly concave and transversely O-like ( Fig. 115 View FIGURES 115 – 123 )........... M. (Merostenus) speculum n. sp.

11(1) Metapleuron setose within ventral half ( Fig. 111 View FIGURES 106 – 114 )................................. M. (Merostenus) reticulatus n. sp.

- Metapleuron bare or with at most one or two setae anteroventrally ( Fig. 50 View FIGURES 49 – 55 : insert).................................12

12(11) Metapleuron extending dorsally to level equal with anterior margin of spiracle ( Fig. 55 View FIGURES 49 – 55 ); propodeum with callus usually at least noticeably convex and often variably distinctly cone-like produced ( Fig. 55 View FIGURES 49 – 55 ), but at least spiracle positioned near mid-length ( Fig. 54 View FIGURES 49 – 55 ); length of pedicel + flagellum more than twice head width and funiculars beyond fl1 more than twice as long as wide ( Fig. 52 View FIGURES 49 – 55 ); fore wing elongate-slender, with marginal vein similar in length to width of wing and with disc uniformly setose ( Fig. 53 View FIGURES 49 – 55 )............................................................... M. (Merostenus) excavatus (Dalman) View in CoL

- Metapleuron extending dorsally obviously anterior to level of spiracle ( Fig. 71 View FIGURES 66 – 73 ); propodeum with callus not distinctly convex and spiracle positioned within about one ocellar diameter from anterior margin ( Figs 70, 73 View FIGURES 66 – 73 ); length of pedicel + flagellum less than twice head width and funiculars beyond fl1 less than twice as long as wide ( Fig. 69 View FIGURES 66 – 73 ); fore wing comparatively broad and short with marginal vein only about 0.6× width of wing and disc basally with variably conspicuous, oblique bare band separated by setae from venation and basal and mediocubital folds ( Fig. 72 View FIGURES 66 – 73 )................ M. (Merostenus) longistylus n. sp.