Meteorus

Key to European species of Meteorus:

1 Dorsope absent (Fig. 18), sometimes weakly indicated (Fig. 19), ventral borders of petiolar tergum (laterotergites) fused or almost joining in middle, from near the base of the petiolar tergum to its midpoint (Fig. 20).......................... 2

– Dorsope distinct; (Fig. 21) ventral borders of petiolar tergum not joining or fused, usually widely separated (Fig. 22)..... 16

2 OOL=0.5–2 (Fig. 23); ocelli large; often yellow/reddish coloured body........................................... 3

– OOL=2–3 (Fig. 24); ocelli small; often darker coloured body (except in colon where OOL=1.5–2 and body yellow to dark). 9

3 Petiolar tergum with the baso-ventral triangular area elongate; tergum fused subbasally (Fig. 25); petiolar terum often with traces of dorsope (Fig. 19).............................................................................. 4

– Petiolar tergum fused ventrally from the base of the segment (Fig. 26); petiolar tergum without traces of dorsopes (Fig. 18). 8

4 Setae on clypeus long (Fig. 27), clypeus short in hight and wide, protruding....................................... 5

– Setae on clypeus short (Fig. 28) or slightly longer than short; clypeus long, narrow and protruding..................... 6

5 Marginal cell of fore wing narrow and short (Fig. 29); antennal articles of ♀ 24–28 (♂ 26–30); upper tooth of mandible long; malar space of ♀ 0.5– 0.8 times basal width of mandible; traces of dorsope on some specimens; colour varying.............................................................................................. M. rubens (Nees, 1811)

– Marginal cell of fore wing wide and long (Fig. 30); antennal articles of ♀ 30–32; malar space of ♀ 0.4 times basal width of mandible; traces of dorsope more or less distinct; body yellow............................ M. heliophilus Fischer 197

6 Body entirely black and rugose (Fig. 31); malar space of ♀ equal or slightly longer than basal width of mandible; antennal articles of ♀ 25–27; OOL =1.2–1.5; ovipositor 1.5–2.0 times length of petiolar tergum...................................................................................................... M. acerbiavorus Belokobylskij et al. 2011

– Body with some parts mostly yellow-coloured.............................................................. 7

7 Clypeus distinctly protruding, rounded (Fig. 105); OOL =0.5 (Fig. 32); setae on clypeus scattered; temples strongly contracted (Fig. 32); length of ovipositor about 1.5–2.0 times length of petiolar tergum; antennal articles of ♀ 31–33.............................................................................................. M. lionotus Thomson, 1895

– Clypeus with peculiar cushion-like shape, protruding but “flattened” (Fig. 28); OOL =1.5; setae on clypeus dense and short; temples rounded; ovipositor 1.5–2.0 times length of petiolar tergum; antennal articles of ♀ 29–33................................................................................................ M. pulchricornis (Wesmael, 1835)

8 Ovipositor slender, length 1.6–2.5 times petiolar tergum; eyes not protruding (Fig. 113); temples rounded; clypeus as wide as face; base of petiolar tergum brownish or blackish; antennal articles of ♀ 27–30............ M. obsoletus (Wesmael, 1835)

– Ovipositor rather thick and 1.4–2.0 times length of petiolar tergum; eyes protruding (Fig. 132); base of petiolar tergum often pale yellow, almost translucent basally (Fig. 33); antennal articles of ♀ 29–33.............. M. versicolor (Wesmael, 1835)

9 Face forming a “shelf” (Fig. 34); wings short and narrow, often infumate (Fig. 35); face strongly convex; propodeum strongly reticulate–rugose, without distinct carinae; occipital carina interrupted medio-dorsally; body compact and dark brown (Fig. 36); antennal articles of ♀ 23–26 (♂ 24–28) OOL =3................................. M. micropterus (Haliday, 1835)

– Face without such shelf; wings longer and wider; body colour varying, often legs yellow; antennal articles of ♀ 21–34... 10

10 Mandibles stout, not twisted, clypeus rather flat (Fig. 98); propodeum with strong anterior transverse carina and medial longitudinal carina (Fig. 37); vein m–cu of fore wing distinctly antefurcal or interstitial; antennal articles of ♀ 21–27; pterostigma dark brown......................................................................................... 11

– Mandibles small and more or less twisted (Fig. 86); clypeus rather protruding; propodeum without anterior transverse carina or with a median longitudinal carina (Fig. 38); vein m–cu of fore wing (sub) interstitial or postfurcal (Fig. 39), exceptionally shortly antefurcal; antennal articles of ♀ 24–34; pterostigma variable.......................................... 12