Gasteruption Latreille, 1797

Tan, Jiang-Li, Achterberg, Cornelis van, Wu, Jia-Xuan, Wang, Hang & Zhang, Qi-Jing, 2021, An illustrated key to the species of Gasteruption Latreille (Hymenoptera, Gasteruptiidae) from Palaearctic China, with description of four new species, ZooKeys 1038, pp. 1-103 : 1

Gasteruption Latreille, 1797 Figs 1-2 , 3 , 4-12 , 13-17 , 18-26 , 27-28 , 29-37 , 38-40 , 41-49 , 50-56 , 57-62 , 63-71 , 72-79 , 80-82 , 83-92 , 93-97 , 98-106 , 107-108 , 109-117 , 118-123 , 124-127 , 128-136 , 137-138 , 139-143 , 144 , 145-154 , 155-156 , 157-165 , 166-167 , 168-173 , 174-175 , 176-187 , 188 , 189-194 , 195-197 , 198-207 , 208-212 , 213-214 , 215-223 , 224-225 , 226-231 , 232-234 , 235-245 , 246-252 , 253 , 254-263 , 264-271 , 272-275 , 276-284 , 285-291 , 292-298 , 299-307

Remarks.

Gasteruption Latreille, 1797: 113; Zhao et al. 2012: 6-7 (diagnosis, references, key); van Achterberg 2013: 59 (key to Dutch spp.); Jennings and Parslow 2014: 95 (Australia); van Achterberg and Talebi 2014: 10 (illustrated key Iran and Turkey); Žikić et al. 2014: 573 (distribution in former Yugoslavia); van Breugel 2014: 424-432 ( Gasteruption in bee hotels); Mao et al. 2014: 1864; Jennings et al. 2015: 399 (New Caledonia); Tan et al. 2016: 53 (illustrated key Pal. China); Johansson and van Achterberg 2016: 74 ( G. assectator aggregate); Lotfalizadeh et al. 2017: 144 (Iran); Saure et al. 2017: 191 (Arabian Peninsula); Bogusch et al. 2018: 4 ( Gasteruption spp. in reed galls); Orlovskytė et al. 2018: 119 (checklist Lithuania). Type-species (designated by Latreille 1810): Ichneumon assectator Linnaeus, 1758.

Key to species of the genus Gasteruption Latreille from Palaearctic China

1	Ovipositor present (a); antenna with 14 segments (b) (females)	2
-	Ovipositor absent (aa); antenna with 13 segments (bb) (males); [if males are unknown, the species is provisionally inserted]	38
2	Apex of ovipositor sheath blackish or dark brown; if narrowly pale apically, then white, ivory or brownish-yellow part at most 0.3 × as long as hind basitarsus (a); (intermediate species are included in both alternatives)	3
-	Apex of ovipositor sheath distinctly white or ivory (but rarely pale brown) and pale part 0.3-8.0 × as long as hind basitarsus (aa)	23
3	Ovipositor sheath 0.6-2.0 × as long as hind tibia and 0.3-1.2 × as long as hind tibia and tarsus combined (a); incision of hypopygium shallow V-shaped and up to apical 0.2 (b) or absent; occipital carina obsolescent to narrowly lamelliform medio-dorsally (c)	4
-	Ovipositor sheath 3.0-7.0 × as long as hind tibia and 1.9-4.0 × as long as hind tibia and tarsus combined (aa); incision of hypopygium often deep and slit-like up to apical 0.3-0.5 (bb); occipital carina obsolescent (c) or distinctly lamelliform (cc) medio-dorsally	16
4	Head in anterior view protruding below lower level of eyes, 0.5-0.6 × length of second antennal segment and 0.4-0.6 × basal width of mandible and mandibular condylus distinctly below lower level of eyes (a); in lateral view condylar incision of malar space remains far removed from eye (b); ovipositor sheath 0.4-0.9 × as long as hind tibia (c)	G. minutum (Tournier, 1877)
-	Head in anterior view slightly protruding below lower level of eyes by less than half basal width of mandible and mandibular condylus near lower level of eyes (aa); in lateral view condylar incision of malar space close to eye (bb), rarely slightly wider; ovipositor sheath 0.7-2.7 × as long as hind tibia (cc)	5
5	Clypeus with rather large shallow depression (a); mesoscutum densely reticulate-rugulose or -rugose (b); hind basitarsus stout (c); apical antennal segment 1.4-1.6 × third antennal segment (d); [ovipositor sheath 0.6-1.5 × as long as hind tibia]	G. hastator (Fabricius, 1804)
-	Clypeus with small depression or depression obsolescent (aa); mesoscutum mainly densely coriaceous or rugulose (bb); hind basitarsus more slender (cc), rarely similarly stout; apical antennal segment at most 1.2 × as long as third antennal segment (dd)	6
6	Mesoscutum coarsely (often “crater” -like) punctate (a); head distinctly emarginate medio-posteriorly (b); head less protruding in lateral view (c) and narrower in anterior view (d)	7
-	Mesoscutum predominantly densely coriaceous, at most with some shallow punctures (aa); head truncate medio-posteriorly or nearly so (bb); head more protruding in lateral view (cc) and wider in anterior view (dd)	8
7	Hind tibia about as long as hind femur and trochanter combined or slightly longer (a); head somewhat longer in dorsal (b) and lateral (c) view; head directly narrowed behind eyes in dorsal view (d)	G. formosanum Enderlein, 1913
-	Hind tibia 1.1-1.2 × as long as hind femur and trochanter combined (aa); head somewhat shorter in dorsal (bb) and lateral (cc) view; head roundly narrowed behind eyes in dorsal view (dd)	G. sinicola (Kieffer, 1924)
8	Vertex strongly bulging above upper level of eyes (a); head comparatively long in dorsal view (b); ovipositor sheath 1.2-1.7 × as long as hind tibia and apex of ovipositor wide and with distinct dorsal teeth (c); propleuron slightly less robust in lateral view (d); [hind tibia moderately slender; propleuron antero-dorsally and pronotum ventrally coriaceous; pronotum convex antero-ventrally]	G. parvicollarium Enderlein, 1913
-	Vertex at most moderately bulging above upper level of eyes (aa); head shorter in dorsal view (bb); ovipositor sheath usually shorter; if 1.2-1.9 × longer than hind tibia, then apex of ovipositor narrow and with minute dorsal teeth (cc); propleuron robust in lateral view (dd)	9
9	Hind tibia slender (a); pronotal sides antero-dorsally granulate (b); side of pronotum slender and with narrow and weakly crenulated grooves (c); ovipositor sheath 1.3-1.9 × as long as hind tibia; [hind basitarsus elongate; hind tibia dark brown to yellowish-brown ventro-basally]	G. granulatum sp. nov.
-	Hind tibia distinctly inflated (aa); pronotal sides antero-dorsally coriaceous or rugulose (bb); side of pronotum robust and with wider and distinctly crenulated grooves (cc); ovipositor sheath 0.7-1.4 × as long as hind tibia	10
10	Mandible black, dark brown or reddish-brown basally (a), rarely narrowly so and largely brownish-yellow; basal depression of mandible rather large and deep (b); tegula dark brown or brown (c); fifth (= pre-apical) sternite dark brown, blackish or narrowly pale medio-apically (d)	11
-	Mandible pale yellow basally (aa); basal depression of mandible often smaller and shallower (bb); tegula yellow (cc), brownish-yellow or brown (ccc); fifth sternite more or less yellowish medio-apically (dd)	14
11	Head in dorsal view directly narrowed posteriorly and longer (a); vertex moderately protruding above eye in lateral view (b); mesopleuron more elongated (c)	G. latitibia Zhao, van Achterberg & Xu, 2012
-	Head in dorsal view rounded narrowed posteriorly and shorter (aa); vertex less protruding above eye in lateral view (bb); mesopleuron less elongated (cc)	12
12	Ovipositor sheath with curved bristles ( “velcro” -type; a); lateral buccal area shallowly depressed (b); hypostomal bridge often longer (behind buccal area at underside of head; c); [pronotum antero-laterally evenly finely sculptured; POL 1.7-2.3 × width of anterior ocellus]	G. nigritarse (Thomson, 1883)
-	Ovipositor sheath with normal straight setae, either largely bristly and erect (aa) or mostly adpressed and finely setose (aaa); lateral buccal area distinctly depressed (bb); hypostomal bridge usually shorter (bb); [sculpture of pronotum antero-laterally variable]	13
13	Ovipositor sheath medially only with short adpressed pale setae at 50 × (lacking upward directed dark brown and short bristly setae) and subapically slightly bristly setose (a); ovipositor sheath not or slightly widened subapically (b), 0.9-1.4 × as long as hind tibia (only to measure if fully exserted); second and third antennal segments usually more robust (c); occipital carina wider latero-dorsally (d); [medially sculpture of mesoscutum at 60 × variable, often dissimilar to very fine sculpture of vertex and more or less rugulose]	G. assectator (Linnaeus, 1758)
-	Ovipositor sheath medially with erect setae or bristles at 50 × and subapically distinctly bristly setose (aa); ovipositor sheath widened subapically (bb), 0.6-1.1 × as long as hind tibia; second and third antennal segments usually more slender (cc); occipital carina narrower latero-dorsally (dd); [medially sculpture of mesoscutum at 60 × variable, frequently similar to fine sculpture of vertex or somewhat coarser	G. abeillei Kieffer, 1912
14	Hind basitarsus rather stout and at least partly ivory dorsally (a); mesoscutum somewhat coarser sculptured (b); fifth metasomal sternite widely pale yellowish posteriorly (c); [hind tibia dark ventrally and hind femur black]	G. flavimarginatum van Achterberg, 2014
-	Hind basitarsus slender and entirely dark brown or brown dorsally (aa); mesoscutum finely sculptured (bb); fifth sternite narrowly pale yellowish posteriorly or mainly dark brown (cc)	15
15	Posterior ocellus situated near upper level of vertex (a); head in dorsal view directly narrowed posteriorly (b); ovipositor sheath 0.5-0.7 × as long as hind tibia (c); [hind femur often partly dark reddish-brown; malar space 0.2-0.3 × basal width of mandible]	G. bicoloratum Tan & van Achterberg, 2016
-	Posterior ocellus situated distinctly below upper level of vertex (aa); head in dorsal view gradually narrowed posteriorly (bb); ovipositor sheath 0.8-1.1 × as long as hind tibia (cc)	G. brevicuspis Kieffer, 1911
16	Vertex of ♀ with reversed V-shaped emargination medio-posteriorly (a; emargination hardly developed in ♂), flat (b) and smooth, shiny and long dorsally (c); mesoscutum of ♀ finely transversely rugose to nearly smooth (d); [dorsal apical teeth of ovipositor distinct]	G. bimaculatum Pasteels, 1958
-	Vertex of ♀ truncate medio-posteriorly (aa) or reversed U-shaped emarginate (aaa), shorter and moderately convex (bb); if vertex more or less emarginate and/or flat, then vertex finely sculptured, with satin sheen and shorter (cc); mesoscutum of ♀ punctate, punctate-rugose or transversely wrinkled (dd)	17
17	Head rather elongate and below eyes slightly enlarged, minimum length of malar space 0.3-0.4 × second antennal segment (a); head distinctly reversed U-shaped emarginate medio-posteriorly (b); mandible and malar space brown (c); hind tarsus brownish apically, paler than basally (d); [apex of ovipositor sheath ivory; first metasomal tergite orange or yellowish-brown]	G. dimidiatum Semenov, 1892
-	Head less elongate and below eyes not enlarged, minimum length of malar space 0.1-0.2 × second antennal segment (aa); head shallowly emarginate medio-posteriorly (bb); if intermediate (bbb), then mandible brownish-yellow and contrasting with colour of malar space (cc); apically hind tarsus as dark brown as basally (dd); [apex of ovipositor sheath dark brown or black]	18
18	Mesosoma sparsely setose laterally (a); pale apical part of ovipositor sheath 0.3-1.0 × as long as hind basitarsus, apex ivory, brownish-yellow or brown (b); hind femur dark brown or black (c)	19
-	Mesosoma densely setose laterally (aa); apex of ovipositor sheath blackish or mainly dark brown (bb); if apex pale, then at most 0.3 × as long as hind basitarsus (bbb); hind femur orange or reddish-brown (cc), but black in G. shengi	20
19	Middle lobe of mesoscutum coarsely punctate (a); vertex strongly convex (b); mandible largely blackish or dark brown (c); mesosoma less elongated (d)	G. sinarum Kieffer, 1911
-	Middle lobe of mesoscutum without punctures and finely transversely wrinkled (aa); vertex moderately convex (bb); mandible yellowish (cc); mesosoma distinctly elongated (dd)	G. pannuceum Tan & van Achterberg, 2016
20	Hind tibia more slender (a); first metasomal tergite dark brown (b); middle lobe of mesoscutum remotely punctate (c); hind femur black or blackish-brown (d); mesoscutum and head black (e)	G. shengi Tan & van Achterberg, 2016
-	Hind tibia more inflated (aa), but intermediate in G. argentifrons and G. coloratum (21bb); first tergite reddish or orange (bb); middle lobe of mesoscutum densely punctate or punctate-rugose (cc); hind femur orange brown to dark brown (dd), but partly or entirely black in G. coloratum ; mesoscutum often paler than head (ee) or both reddish	20
21	Ovipositor sheath 3.1-4.4 × as long as hind tibia (a); hind tibia more inflated (b); vertex longer setose (c); mesosoma largely or entirely black laterally (d); [hind femur and tibia (except basally) similarly coloured, orange brown or dark brown]	G. dilutum Semenov, 1892
-	Ovipositor sheath approx. 7.0 × as long as hind tibia (aa); hind tibia less inflated (bb); vertex shorter setose (cc); mesosoma often dark reddish or orange brown laterally (dd)	22
22	Basal half of hind coxa mainly transversely rugose or punctate dorsally (a); apex of ovipositor sheath largely dark brown or brown (b); pronotum longer setose (c); [hind coxa orange brown or blackish]	G. coloratum Zhao, van Achterberg & Xu, 2012
-	Basal half of hind coxa superficially coriaceous dorsally (aa); apex of ovipositor sheath ivory or brownish-yellow (bb); pronotum shorter setose (cc)	G. argentifrons Semenov-T.-S. & Kostylev, 1928
23	Head with medial depression in front of occipital carina and with pair of lateral depressions (a); if shallow, then head in dorsal view nearly parallel-sided behind eyes (b); occipital carina wide lamelliform medio-dorsally (c)	24
-	Head flat or evenly convex in front of occipital carina (aa); if with a shallow depression in front of occipital carina (aaa), then head directly narrowed behind eyes (bb) and occipital carina at most moderately lamelliform medio-dorsally (cc)	26
24	Propleuron moderately robust and 0.8-1.0 × as long as mesoscutum in front of tegula (a); vertex medially weakly convex in lateral view (b); head shorter in dorsal view (c); mandible often pale in anterior view medially (d); [white or ivory part of ovipositor sheath 1.7-3.3 × longer than hind basitarsus]	G. oshimense Watanabe, 1934
-	Propleuron slender and 1.0-1.2 × as long as mesoscutum in front of tegula (aa); vertex medially nearly flat in lateral view (bb); head comparatively long in dorsal view (cc); mandible often darker in anterior view (dd)	25
25	Head in dorsal view distinctly narrowed behind eyes (a); middle lobe of mesoscutum with fine transverse elements anteriorly (b; sometimes coarsely sculptured); propleuron in ventral view less slender anteriorly (c); white or ivory apical part of ovipositor sheath 2.4-3.8 × longer than hind basitarsus (d)	G. corniculigerum Enderlein, 1913
-	Head in dorsal view nearly parallel-sided behind eyes (aa); middle lobe of mesoscutum only coriaceous between punctures (bb); propleuron in ventral view more slender anteriorly (cc); white or ivory apical part of ovipositor sheath 1.0-2.1 × longer than hind basitarsus (dd)	G. kexinae sp. nov.
26	Ovipositor sheath comparatively wide and about 0.9 × as long as hind tibia, 0.3 × as long as metasoma and 0.2 × as long as body (a); middle lobe of mesoscutum rather protuberant in lateral view (b); pronotal tooth slender and acute	G. assectoides Zhao, van Achterberg & Xu, 2012
-	Ovipositor sheath comparatively narrow and 1.1-9.0 × as long as hind tibia, 0.6-2.8 × as long as metasoma and 0.4-1.4 × as long as body (aa); middle lobe of mesoscutum less protuberant in lateral view (bb); if convex (bbb), then pronotal tooth wider and rather blunt (cc)	27
27	Ovipositor about 0.4 × as long as body and 0.6 × as long as metasoma (a); hind coxa very slender (b); ovipositor widened apico-ventrally and more or less angularly up-curved apically in dead specimens (c)	G. angulatum Zhao, van Achterberg & Xu, 2012
-	Ovipositor 0.8-1.4 × as long as body and 1.2-1.9 × as long as metasoma (aa); hind coxa slightly less slender (bb); ovipositor narrow apico-ventrally and nearly straight or gradually up-curved apically (cc)	28
28	Hind femur and tibia widened (a); hind basitarsus robust (b); head slightly narrowed in dorsal view (c); head slender in anterior view (d) and face narrower than clypeus (e); hind basitarsus entirely dark brown (f); [ovipositor sheath about 1.4 × as long as body and 8.5 × as long as hind tibia]	G. huangshii Tan & van Achterberg, 2016
-	Hind femur and tibia slender (aa); hind basitarsus more slender (bb); head in dorsal view distinctly narrowed (cc); head in anterior view subglobular (dd); if slender (ddd), then face as wide as clypeus (ee); hind basitarsus often partly ivory (ff)	29
29	Pale apical part of ovipositor sheath 0.2-1.0 × as long as hind basitarsus (a); occipital carina non-lamelliform medio-dorsally (b) and mesoscutum distinctly punctate or rugose (c); if narrow lamelliform (bb), then hypopygium yellowish-brown or yellow; [ovipositor sheath 1.0-1.3 × as long as body]	30
-	Pale apical part of ovipositor sheath 1.1-3.5 × as long as hind basitarsus (aa); occipital carina narrow lamelliform medio-dorsally (bb) and hypopygium dark brown or black; if non-lamelliform (bbb), then mesoscutum very finely coriaceous and, at most, punctulate (cc) or transversely rugulose	32
30	Hypopygium dark brown or black (a); mesoscutum between coarse punctures with satin sheen and densely punctulate (b); head longer in dorsal view (c); face with short setosity laterally (d); [mandible dark brown or brown in anterior view]	G. sinarum Kieffer, 1911
-	Hypopygium yellowish-brown or yellow (aa); mesoscutum between punctures rather shiny and sparsely punctulate (bb); head shorter in dorsal view (cc); face with long setosity laterally (dd)	31
31	Head slightly elongated ventrally (a); mandible largely dark brown in anterior view (b); mesosoma dorsally black (c), hind coxa (d), hind femur (e) and hind basitarsus (f) dark brown	G. dimidiatum Semenov, 1892
-	Head short ventrally (aa); mandible yellow in anterior view (bb); mesosoma dorsally (cc), hind coxa (dd) and femur (ee) reddish or orange brown; hind basitarsus mainly ivory (ff)	G. argentifrons Semenov T.-S. & Kostylev, 1928
32	Notauli with transverse rugae posteriorly and shallow (a) and anteriorly narrow, finely crenulate or nearly smooth (b); middle lobe of mesoscutum very finely transversely rugulose (c) and vertex (d) dull and finely coriaceous (as temple dorsally (e))	G. reductum sp. nov.
-	Notauli only crenulate posteriorly and distinctly impressed (aa) and anteriorly wider and moderately crenulate (bb); middle lobe of mesoscutum very finely coriaceous (cc); if finely transversely rugulose, then vertex (dd) and temple dorsally (ee) shiny and largely smooth	33
33	Occipital carina non-lamelliform medio-dorsally and narrow laterally (a); head gradually narrowed in dorsal view (b) and short (c); vertex in lateral view more (d) or less (dd) above level of ocelli; head dorsally with satin sheen (e)	34
-	Occipital carina narrowly lamelliform medio-dorsally and moderately wide laterally (aa); head usually directly narrowed posteriorly in dorsal view (bb); if gradually narrowed (bbb), then head longer (cc); vertex in lateral view near level of ocelli (dd); head dorsally more or less shiny (ee)	35
34	Mesoscutum densely punctate (a) and punctulate-coriaceous between punctures (b); pronotal side more or less rugose or rugulose ventrally (c); white or ivory apical part of ovipositor sheath 1.1-1.9 × as long as hind basitarsus (d)	G. subtile (Thomson, 1883)
-	Mesoscutum at most sparsely punctulate (aa) and very finely coriaceous between minute punctures (bb); pronotal side entirely finely coriaceous ventrally (cc); white or ivory apical part of ovipositor sheath 2.1-2.6 × as long as hind basitarsus (dd)	G. pedion sp. nov.
35	Head elongate-elliptical in dorsal view (a); propleuron 1.1-1.2 × as mesoscutum in front of tegula (b); mesosoma more slender in lateral view (c); mesoscutum less convex dorsally (d); hind tibia slender (e)	G. amoyense Pasteels, 1958
-	Head trapezoid in dorsal view (aa); propleuron 0.9-1.0 × mesoscutum in front of tegula (bb); mesosoma less slender in lateral view (cc); mesoscutal lobes distinctly convex dorsally (dd); hind tibia more robust (ee) or slender (e)	36
36	Pale apical part of ovipositor sheath 3.0-3.5 × as long as hind basitarsus (a); fourth antennal segment 1.7-2.3 × as long as third antennal segment (b); vertex shiny and largely smooth or finely punctulate (c), without shallow depression medio-posteriorly (d) and in lateral view distinctly convex (e); [hind basitarsus black]	G. tonkinense Pasteels, 1958
-	Pale apical part of ovipositor sheath 1.1-2.4 × as long as hind basitarsus (aa); fourth antennal segment 1.2-1.9 × as long as third antennal segment (bb); head dorsally with satin sheen and finely sculptured (cc), rather often with shallow depression medio-posteriorly (dd; G. japonicum ) and vertex less convex (ee)	37
37	Lobes of mesoscutum distinctly convex in lateral view (a); middle mesoscutal lobe more protuberant in dorsal (b) and lateral (c) view; fourth antennal segment 1.7-1.9 × as long as third segment (d); hind tibia more slender (e); [occipital carina fine and non-lamelliform dorsally; vertex in front of occipital carina without depression]	G. sinepunctatum Zhao, van Achterberg & Xu, 2012
-	Lobes of mesoscutum comparatively flat in lateral view (aa); middle mesoscutal lobe less protuberant in dorsal (bb) and lateral (cc) view; fourth antennal segment 1.2-1.5 × as long as third segment (dd); hind tibia less slender (ee); [hind basitarsus often partly ivory]	G. japonicum Cameron, 1888

Males

38	Vertex with distinct medio-posterior depression or a groove with two minute tubercles in front of distinctly lamelliform occipital carina (a); mesoscutum medially transversely or obliquely rugulose, in large specimens transversely rugose (b); occipital carina wide lamelliform (c)	39
-	Vertex flat or evenly convex in front of occipital carina (aa); if slightly depressed (aaa), then mesoscutum mainly punctate medially (bb) or occipital carina narrow lamelliform (cc)	41
39	Propleuron moderately robust and 0.8-1.0 × as long as mesoscutum in front of tegula (a); fifth antennal segment 2.2-2.9 × as long as third segment (b); head shorter in dorsal view (c)	G. oshimense Watanabe, 1934
-	Propleuron slender and 1.0-1.2 × as long as mesoscutum in front of tegula (aa); fifth antennal segment 1.8-2.1 × as long as third segment (bb); head comparatively long in dorsal view (cc)	40
40	Middle lobe of mesoscutum with transverse elements (a); mesoscutum distinctly rugose medio-posteriorly (b); hind femur slightly more slender (c)	G. corniculigerum Enderlein, 1913
-	Middle lobe of mesoscutum without transverse elements, only coriaceous between punctures (aa); mesoscutum only punctate medio-posteriorly (bb); hind femur slightly widened (cc)	G. kexinae sp. nov.
41	Clypeus with rather large shallow depression (a); hind basitarsus rather stout (b); mesoscutum reticulate or rugose (c); [head and scapus more or less orange or reddish-brown, but sometimes entirely black]	G. hastator (Fabricius, 1804)
-	Clypeus with small depression or depression obsolescent (aa); hind basitarsus often more slender (bb) or mesoscutum coriaceous or rugulose (cc)	42
42	Head in anterior view distinctly protruding below lower level of eyes (a), in lateral view condylar incision of malar space remains distinctly removed from eye, malar area behind indentation square and at least 0.8 × as long as second antennal segment (= pedicellus) and 0.6-0.9 × basal width of mandible (b); [mesoscutum densely coriaceous and matt, similar to vertex]	G. minutum (Tournier, 1877)
-	Head in anterior view hardly protruding below lower level of eyes (aa), in lateral view condylar incision of malar space close to eye and malar area behind indentation transverse and 0.3-0.5 × as long as second antennal segment and 0.2-0.3 × basal width of mandible (bb), rarely slightly longer (aaa, bbb)	43
43	Mesoscutum only coriaceous or finely rugulose medially (a), at most with a few shallow punctures; [♂ unknown of G. assectoides , G. granulatum and G. pannuceum and are provisionally included]	44
-	Mesoscutum with several distinctly impressed punctures medially (aa; but often shallow in G. japonicum ) or reticulate-rugose (aaa)	60
44	Hind tibia slender, hardly to moderately inflated (a); mesoscutum often very finely and regularly sculptured (b)	45
-	Hind tibia distinctly inflated (aa); mesoscutum mainly densely coriaceous or irregularly rugulose (aa), especially near notauli (bb)	54
45	Mesoscutum distinctly regularly transversely rugulose (a); hind tibial spurs yellowish and distinctly contrasting with dark hind basitarsus (b)	G. assectoides Zhao, van Achterberg & Xu, 2012
-	Mesoscutum mainly finely coriaceous or superficially irregularly rugulose (aa); hind tibial spurs more or less brown and less contrasting with hind basitarsus (bb)	46
46	Fourth antennal segment 1.8-3.5 × as long as third segment (a); face rather narrow (b)	47
-	Fourth antennal segment 1.4-1.7 × as long as third segment (aa; unknown of G. pannuceum and G. granulatum ); face wide (bb)	50
47	Hind femur rather robust (a); second antennal segment (= pedicellus) more slender (b); middle lobe of mesoscutum less protuberant in lateral view (c); [fourth antennal segment 2.5-2.9 × as long as third segment]	G. huangshii Tan & van Achterberg, 2016
-	Hind femur slender (aa); pedicellus robust (bb); middle lobe of mesoscutum more protruding in lateral view (cc)	48
48	Mandible medially yellow (a); fourth antennal segment 2.5-3.5 × as long as third segment (b); vertex largely smooth or densely punctulate (c)	G. sinepunctatum Zhao, van Achterberg & Xu, 2012
-	Mandible medially black or dark brown (aa); fourth antennal segment 1.8-2.3 × as long as third segment (bb); vertex coriaceous (cc)	49
49	Mesoscutum with fine transverse rugulae (a); propleuron less elongate (b); middle lobe of mesoscutum less protruding (c)	G. reductum sp. nov.
-	Mesoscutum with transverse rugulae absent or with very fine rugulae (aa); propleuron more elongate (bb); middle lobe of mesoscutum more protruding (cc)	G. pedion sp. nov.
50	Head strongly convex in lateral view (a); head longer in dorsal view (b); hind coxa and tibia rather robust (c); [mandible dark brown]	G. parvicollarium Enderlein, 1913 s. str.
-	Head moderately convex in lateral view (aa); head rather short in dorsal view (bb); hind coxa and tibia slender (cc)	51
51	Hind coxa distinctly narrower than hind tibia (a); hind femur narrower medially (b); mesosternal sulcus narrow and largely smooth (c); mandible dark brown basally (d)	G. angulatum Zhao, van Achterberg & Xu, 2012
-	Hind coxa about as wide as hind tibia (aa); hind femur wider medially (bb); mesosternal sulcus wide and coarsely crenulate (cc); mandible brownish-yellow basally (dd)	52
52	Anterior half of propleuron parallel-sided and long in ventral view (a); propleuron 1.1-1.2 × as long as mesoscutum up to tegula in lateral view (b); head comparatively long in dorsal view (c); [eye elongate in lateral view; ♂ unknown]	G. amoyense Pasteels, 1958
-	Anterior half of propleuron narrowed anteriorly and rather short in ventral view (aa); propleuron 0.8-0.9 × as long as mesoscutum up to tegula in lateral view (bb); head short in dorsal view (cc)	53
53	Mesoscutum densely and finely granulate (a); scutellum granulate and rather flat (b); frons granulate and matt (c); [hind tibia slender and yellowish-brown ventro-basally]	G. granulatum sp. nov.
-	Mesoscutum rugulose or punctate (aa); scutellum rugulose and slightly more convex (bb); frons largely smooth, and more or less shiny (cc); [♂ unknown]	G. pannuceum Tan & Achterberg, 2016
54	Frons and vertex shiny and smooth (a); mesoscutum rugose medio-posteriorly (b) and near notauli (c); hind femur slightly wider (c); [mesoscutum with satin sheen]	G. latitibia Zhao, van Achterberg & Xu, 2012
-	Frons and vertex matt or with satin sheen, micro-sculptured (aa); mesoscutum medio-posteriorly rugulose (bb) or mainly punctate and near notauli coriaceous or rugulose (cc); hind femur usually more slender (dd)	55
55	Apex of paramere yellowish-brown (a); pre-apical metasomal sternite distinctly yellowish posteriorly (b); mandible yellowish basally (c)	G. flavimarginatum van Achterberg, 2014
-	Apex of paramere dark brown (aa); pre-apical metasomal sternite at most narrowly yellowish posteriorly (bb); colour of mandible variable, often darkened basally (cc)	56
56	Mandible largely pale yellowish (a)	57
-	Mandible largely brown, dark brown or black (aa); [additional females needed for reliable identification]	58
57	Middle lobe of mesoscutum distinctly protruding (a); head longer and rather trapezoid in dorsal view (b); hind tibia dark brown or blackish ventrally (c); scutellum wider (d)	G. brevicuspis Kieffer, 1911
-	Middle lobe of mesoscutum hardly protruding (aa); head shorter and transverse in dorsal view (bb); hind tibia more or less yellowish-brown ventrally (cc); scutellum narrower (dd)	G. bicoloratum Tan & van Achterberg, 2016
58	Hind tibia with ill-defined pale subbasal patch (a); hypostomal bridge usually medium-sized (b)	G. nigritarse (Thomson, 1883)
-	Hind tibia usually with well-defined subbasal ivory patch (aa); hypostomal bridge narrow (bb)	59
59	Mesoscutum often coarser sculptured than vertex (a); head directly narrowed behind eyes (b); temple rather convex (c)	G. assectator (Linnaeus, 1758)
-	Mesoscutum slightly coarser sculptured than vertex (aa); head less directly narrowed behind eyes (bb); temple less convex (cc)	G. abeillei Kieffer, 1912
60	Posteriorly vertex flat in lateral view and long (a); head smooth and shiny dorsally (b); head moderately narrowed posteriorly (c); mesosoma laterally often paler than dorsally (d)	G. bimaculatum Pasteels, 1958
-	Posteriorly vertex convex in lateral view and usually shorter (aa); sculpture of head dorsally variable (bb); if smooth (bbb), then more narrowed posteriorly (cc); mesosoma usually unicoloured (dd) or dorsally paler than laterally	61
61	Hind coxa orange brown or dark brown (a); mesoscutum conspicuously setose (b); metasoma largely reddish-brown (c); [mandible orange yellow or yellowish-brown; mesoscutum finely or coarsely punctate and often with narrow interspaces]	62
-	Hind coxa black (aa); mesoscutum less conspicuously setose (bb); metasoma often largely dark brown or black (cc)	64
62	Mesoscutum finely punctate, with rather wide interspaces (a); hind tibia yellowish-brown or indistinctly infuscate basally (b); apical half of hind basitarsus partly dark brown and only apically ivory (c)	G. dilutum Semenov, 1892
-	Mesoscutum coarsely punctate and interspaces narrower (aa); hind tibia distinctly dark brown basally (bb); apical half of hind basitarsus mainly ivory (cc)	63
63	Basal half of hind coxa rugose dorsally (a); outer side of hind tibia (except basally) dark brown or blackish (b); head subtruncate posteriorly in dorsal view (c)	G. coloratum Zhao, van Achterberg & Xu, 2012
-	Basal half of hind coxa superficially coriaceous dorsally (aa); ventral half of outer side of hind tibia orange-brown (bb); head emarginate posteriorly in dorsal view (cc)	G. argentifrons Semenov-T.-S. & Kostylev, 1928
64	Third antennal segment slightly longer than wide and similar to pedicellus (a); ventral half of pronotal side largely superficially coriaceous to nearly smooth, only grooves crenulate (b); pronotum partly densely setose (c)	65
-	Third antennal segment less robust compared to pedicellus and distinctly longer than wide (aa); ventral half of pronotal side largely moderately reticulate-rugose, at most ventrally coriaceous (bb); pronotum sparsely setose (cc)	66
65	Malar space narrow (a); head less emarginate medio-posteriorly (b); mesoscutum usually with less coarse sculpture (c); scutellum mainly micro-sculptured (d), at most with few large punctures	G. shengi Tan & van Achterberg, 2016
-	Malar space slightly wider (aa); head distinctly emarginate medio-posteriorly (bb); mesoscutum with coarser sculpture (cc); scutellum coarsely punctate (dd)	G. dimidiatum Semenov, 1892
66	Hind tibia distinctly inflated and bulging ventrally (a); head directly narrowed posteriorly in dorsal view (b); third antennal segment slender, 1.6-1.9 × as long as second segment (c); [mesoscutum distinctly “crater-like” punctate; head concave medio-posteriorly]	67
-	Hind tibia slender and hardly bulging ventrally (aa); head usually gradually narrowed posteriorly in dorsal view (bb); third antennal segment robust, 1.2-1.7 × as long as second segment (cc)	68
67	Hind tibia strongly inflated (a); third antennal segment slightly more robust (b)	G. sinicola (Kieffer, 1924)
-	Hind tibia less inflated (aa); third antennal segment slender (bb)	G. formosanum Enderlein, 1913
68	Occipital carina moderately wide (a); vertex distinctly convex (b); [middle lobe of mesoscutum coarsely punctate laterally]	G. tonkinense Pasteels, 1958
-	Occipital carina narrow lamelliform or non-lamelliform (aa); vertex comparatively flat (bb)	69
69	Occipital carina narrow lamelliform (a) and vertex slightly depressed medio-dorsally (b); mesoscutum less coarsely punctate (c)	G. japonicum Cameron, 1888
-	Occipital carina less or non-lamelliform (aa) and vertex flat medio-dorsally (bb); mesoscutum more or less coarsely punctate (cc)	70
70	Lateral lobe of mesoscutum rather matt and at most finely punctate (a); head slightly enlarged below eyes in anterior view (b)	G. subtile (Thomson, 1883)
-	Lateral lobe of mesoscutum with satin sheen and with coarse punctures (aa); head not enlarged below eyes in anterior view (bb)	G. sinarum Kieffer, 1911

Systematics

Figures

Figure 3. Gasteruption abeillei Kieffer, male, Shaanxi, habitus lateral.

Figure 144. Gasteruption latitibia Zhao, van Achterberg & Xu, female, Shaanxi, habitus lateral.

Figure 188. Gasteruption nigritarse (Thomson), male, Shaanxi, habitus lateral.

Figure 253. Gasteruption reductum Tan & van Achterberg, sp. nov., female, holotype, habitus lateral.

Figures 1, 2. Gasteruption abeillei Kieffer, female, Shaanxi 1 habitus lateral 2 detailed apical half of ovipositor sheath lateral.

Figures 4 - 12. Gasteruption abeillei Kieffer, female, Shaanxi 4 head lateral 5 mesosoma lateral 6 mesosoma dorsal 7 wings 8 ovipositor and its sheath lateral 9 head anterior 10 head dorsal 11 hind leg 12 antenna.

Figures 13 - 17. Gasteruption amoyense Pasteels, female, Shaanxi 13 habitus lateral 14 propleuron ventral 15 apex of ovipositor 16 apex of antenna 17 base of antenna.

Figures 18 - 26. Gasteruption amoyense Pasteels, female, Shaanxi 18 head lateral 19 mesosoma lateral 20 mesosoma dorsal 21 wings 22 apex of metasoma ventral 23 apex of ovipositor sheath lateral 24 head anterior 25 head dorsal 26 hind leg lateral.

Figures 27 - 28. Gasteruption angulatum Zhao, van Achterberg & Xu, male, Shaanxi 27 habitus lateral 28 apex of metasoma lateral.

Figures 29 - 37. Gasteruption angulatum Zhao, van Achterberg & Xu, male, Shaanxi 29 head lateral 30 mesosoma lateral 31 mesosoma dorsal 32 wings 33 propleuron ventral 34 head anterior 35 head dorsal 36 hind leg 37 base of antenna.

Figures 38 - 40. Gasteruption bimaculatum Pasteels, female, Shaanxi, habitus lateral.

Figures 41 - 49. Gasteruption bimaculatum Pasteels, female, Shaanxi 41 head lateral 42 mesosoma lateral 43 mesosoma dorsal 44 wings 45 apex of metasoma ventral 46 head anterior 47 head dorsal 48 hind leg 49 apex of ovipositor sheath lateral.

Figures 50 - 56. Gasteruption bimaculatum Pasteels, male, Shaanxi 50 habitus lateral 51 apex of antenna 52 mesosoma dorsal 53 hind leg 54 base of antenna 55 head dorsal 56 apex of metasoma lateral.

Figures 57 - 62. Gasteruption brevicuspis Kieffer, female, Shaanxi 57 habitus lateral 58 ovipositor and its sheath 59 propleuron ventral 60 apex of antenna lateral 61 apex of antenna latero-ventral 62 ovipositor apex lateral.

Figures 63 - 71. Gasteruption brevicuspis Kieffer, female, Shaanxi 63 head lateral 64 mesosoma lateral 65 mesosoma dorsal 66 hind leg 67 head anterior 68 head dorsal 69 base of antenna lateral 70 fore wing 71 apex of metasoma ventral.

Figures 72 - 79. Gasteruption brevicuspis Kieffer, male, Shaanxi 72 habitus lateral 73 apex of metasoma lateral 74 base of antennae 75 mesosoma lateral 76 mesosoma dorsal 77 hind legs 78 head dorsal 79 apex of antenna.

Figures 80 - 82. Gasteruption coloratum Zhao, van Achterberg & Xu, female, Xinjiang 80 habitus lateral 81 apex of ovipositor lateral 82 id., ventral.

Figures 83 - 92. Gasteruption coloratum Zhao, van Achterberg & Xu, female, Xinjiang 83 head lateral 84 mesosoma lateral 85 mesosoma dorsal 86 wings 87 base of antenna lateral 88 apex of metasoma ventral 89 head anterior 90 head dorsal 91 hind leg 92 apex of ovipositor sheath.

Figures 93 - 97. Gasteruption corniculigerum Enderlein, female, Shaanxi 93 habitus lateral 94 apex of ovipositor lateral 95 apex of antenna 96 base of antenna 97 apex of metasoma ventral.

Figures 98 - 106. Gasteruption corniculigerum Enderlein, female, Shaanxi 98 head lateral 99 mesosoma lateral 100 mesosoma dorsal 101 propleuron ventral 102 fore wing 103 apex of ovipositor sheath 104 head anterior 105 head dorsal 106 hind leg.

Figures 107 - 108. Gasteruption granulatum Tan & van Achterberg, sp. nov., female, holotype 107 habitus lateral 108 propleuron ventral.

Figures 109 - 117. Gasteruption granulatum Tan & van Achterberg, sp. nov., female, holotype 109 head lateral 110 mesosoma lateral 111 mesosoma dorsal 112 hind leg 113 apex of ovipositor sheath 114 head anterior 115 head dorsal 116 wings 117 apex of metasoma ventral.

Figures 118 - 123. Gasteruption granulatum Tan & van Achterberg, sp. nov., male, paratype 118 habitus lateral 119 mesosoma dorsal 120 hind leg 121 head dorsal 122 basal antennal segments 123 apex of metasoma lateral.

Figures 124 - 127. Gasteruption kexinae Tan & van Achterberg, sp. nov., female, holotype 124 habitus lateral 125 apex of metasoma ventral 126 base of antenna 127 details of vertex dorsal.

Figures 128 - 136. Gasteruption kexinae Tan & van Achterberg, sp. nov., female, holotype 128 head lateral 129 mesosoma lateral 130 mesosoma dorsal 131 wings 132 propleuron ventral 133 apex of ovipositor sheath 134 head anterior 135 head dorsal 136 hind leg.

Figures 137 - 138. Gasteruption kexinae Tan & van Achterberg, sp. nov., male, paratype 137 habitus lateral 138 apex of metasoma lateral.

Figures 139 - 143. Gasteruption kexinae Tan & van Achterberg, sp. nov., male, paratype 139 mesosoma dorsal 140 hind leg 141 base of antenna 142 head dorsal 143 head lateral.

Figures 145 - 154. Gasteruption latitibia Zhao, van Achterberg & Xu, female, Shaanxi 145 head lateral 146 mesosoma lateral 147 mesosoma dorsal 148 hind leg 149 ovipositor and its sheath lateral 150 head anterior 151 head dorsal 152 wings 153 base of antenna 154 hypopygium ventral.

Figures 155 - 156. Gasteruption minutum (Tournier), female, Shaanxi 155 habitus lateral 156 ovipositor and its sheath lateral.

Figures 157 - 165. Gasteruption minutum (Tournier), female, Shaanxi 157 head lateral 158 mesosoma lateral 159 mesosoma dorsal 160 apex of metasoma ventral 161 base of antenna 162 head anterior 163 head dorsal 164 hind leg 165 apex of antenna.

Figures 166 - 167. Gasteruption minutum (Tournier), male, Shaanxi 166 habitus lateral 167 basal antennal segments.

Figures 168 - 173. Gasteruption minutum (Tournier), male, Shaanxi 168 head lateral 169 mesosoma dorsal 170 hind leg lateral 171 head anterior 172 head dorsal 173 apex of metasoma lateral.

Figures 174 - 175. Gasteruption nigritarse (Thomson), female, Shaanxi 174 habitus lateral 175 ovipositor and its sheath lateral.

Figures 176 - 187. Gasteruption nigritarse (Thomson), female, Shaanxi 176 head lateral 177 details of hypostomal bridge 178 mesosoma lateral 179 mesosoma dorsal 180 fore wing 181 hind leg 182 head anterior 183 head dorsal 184 apex of metasoma ventral 185 details of apex of ovipositor sheath 186 base of antenna 187 apex of antenna.

Figures 189 - 194. Gasteruption nigritarse (Thomson), male, Shaanxi 189 mesosoma dorsal 190 apex of metasoma lateral 191 base of antenna 192 head dorsal 193 hind legs 194 apex of antenna.

Figures 195 - 197. Gasteruption oshimense Watanabe, large female, Shaanxi 195 habitus lateral 196 pronotum ventral 197 head and pronotum lateral.

Figures 198 - 207. Gasteruption oshimense Watanabe, large female, Shaanxi 198 head lateral 199 mesosoma lateral 200 mesosoma dorsal 201 hind leg 202 apex of ovipositor sheath lateral 203 head anterior 204 head dorsal 205 wings 206 apex of metasoma ventral 207 medio-posterior depression of head latero-dorsal.

Figures 208 - 212. Gasteruption oshimense Watanabe, male, Shaanxi 208 mesosoma dorsal 209 hind leg 210 head dorsal 211 apex of metasoma lateral 212 basal antennal segments lateral.

Figures 213 - 214. Gasteruption parvicollarium Enderlein, ♀, Shaanxi 213 habitus lateral 214 apex of ovipositor lateral.

Figures 215 - 223. Gasteruption parvicollarium Enderlein, ♀, Shaanxi 215 head lateral 216 mesosoma lateral 217 mesosoma dorsal 218 hind leg 219 ovipositor and ovipositor sheath 220 head anterior 221 head dorsal 222 wings 223 apex of metasoma ventral.

Figures 224 - 225. Gasteruption parvicollarium Enderlein, ♂, Shaanxi 224 habitus lateral 225 apex of metasoma lateral.

Figures 226 - 231. Gasteruption parvicollarium Enderlein, ♂, Shaanxi 226 head lateral 227 mesosoma dorsal 228 hind leg lateral 229 basal antennal segments lateral 230 head anterior 231 head dorsal.

Figures 232 - 234. Gasteruption pedion Tan & van Achterberg, sp. nov., female, holotype 232 habitus lateral 233 apex of ovipositor lateral 234 propleuron ventral.

Figures 235 - 245. Gasteruption pedion Tan & van Achterberg, sp. nov., female, holotype 235 head lateral 236 mesosoma lateral 237 mesosoma dorsal 238 fore wing 239 hind leg 240 head anterior 241 head dorsal 242 apex of metasoma ventral 243 apex of ovipositor sheath 244 base of antenna 245 apex of antenna.

Figures 246 - 252. Gasteruption pedion Tan & van Achterberg, sp. nov., male, paratype 246 habitus lateral 247 apex of metasoma lateral 248 head lateral 249 mesosoma dorsal 250 head dorsal 251 base of antenna 252 hind leg.

Figures 254 - 263. Gasteruption reductum Tan & van Achterberg, sp. nov., female, holotype 254 head lateral 255 mesosoma lateral 256 mesosoma dorsal 257 hind leg 258 head anterior 259 head dorsal 260 fore wing 261 apex of metasoma ventral 262 base of antenna 263 apex of ovipositor sheath.

Figures 264 - 271. Gasteruption reductum Tan & van Achterberg, sp. nov., male, paratype 264 habitus lateral 265 head lateral 266 mesosoma lateral 267 mesosoma dorsal 268 head dorsal 269 apex of metasoma lateral 270 hind leg 271 base of antenna.

Figures 272 - 275. Gasteruption sinarum Kieffer, female, Shaanxi 272 habitus lateral 273 base of antenna 274 apex of antenna 275 apex of ovipositor lateral.

Figures 276 - 284. Gasteruption sinarum Kieffer, female, Shaanxi 276 head lateral 277 mesosoma lateral 278 mesosoma dorsal 279 wings 280 apex of metasoma ventral 281 head anterior 282 head dorsal 283 apex of ovipositor sheath 284 hind leg.

Figures 285 - 291. Gasteruption sinarum Kieffer, male, Shaanxi 285 habitus lateral 286 mesosoma dorsal 287 hind leg 288 head dorsal 289 apex of metasoma lateral 290 base of antenna 291 apex of antenna.

Figures 292 - 298. Gasteruption sinepunctatum Zhao, van Achterberg & Xu, male, Shaanxi 292 habitus lateral 293 mesosoma dorsal 294 fore wing 295 hind leg lateral 296 basal antennal segments lateral 297 head dorsal 298 apex of metasoma lateral.

Figures 299 - 307. Gasteruption subtile Thomson, female, Shaanxi 299 head lateral 300 mesosoma lateral 301 mesosoma dorsal 302 apex of metasoma ventral 303 base of antenna 304 head anterior 305 head dorsal 306 hind leg 307 apex of ovipositor sheath.