Ichneumon wasps (Hymenoptera: Ichneumonidae) of the subfamily Campopleginae are treated. A hundred species are included, forty-two of which are reported for the first time from Belgium: Campoletis crassicornis (Tschek, 1871), Campoletis punctata (Bridgman, 1886), Campoletis thomsoni (Roman, 1915), Campoletis varians (Thomson, 1887), Campoplex formosanae Horstmann, 2012, Campoplex tibialis (Szépligeti, 1916), Casinaria mesozosta (Gravenhorst, 1829), Casinaria pyreneator Aubert, 1960, Cymodusa australis (Smits van Burgst, 1913), Cymodusa declinator (Gravenhorst, 1829), Diadegma crassiseta (Thomson, 1887), Diadegma flexum Horstmann, 1973, Diadegma kyffhusanae Horstmann, 1973, Diadegma maculatum (Gravenhorst, 1829), Diadegma micrurum (Thomson, 1887), Diadegma neomajale Horstmann, 1969, Diadegma rufigaster Horstmann, 1973, Dusona insignita (Förster, 1868), Dusona libertatis (Teunissen, 1947), Dusona limnobia (Thomson, 1887), Dusona minor (Provancher, 1879), Dusona pulchripes (Holmgren, 1872), Echthronomas facialis (Thomson, 1887), Enytus parvicanda (Thomson, 1887), Eriborus terebrans (Gravenhorst, 1829), Hyposoter aglyphus Galsworthy et Shaw, 2023, Hyposoter castaneus Galsworthy et Shaw, 2023, Hyposoter inquinatus (Holmgren, 1860), Hyposoter placidus (Desvignes, 1856), Hyposoter virginalis (Gravenhorst, 1829), Nemeritis caudatula Thomson, 1887, Nemeritis lativentris Thomson, 1887, Nemeritis specularis Horstmann, 1975, Nepiesta mandibularis (Holmgren, 1860), Olesicampe proterva (Brischke, 1880), Olesicampe radiella (Thomson, 1885), Olesicampe retusa (Thomson, 1887), Phobocampe lymantriae Gupta, 1983, Phobocampe tempestiva (Holmgren, 1860), Porizon albistriae (Horstmann, 1987), Rhimphoctona lucida (Clément, 1924), and Sinophorus nitidus (Brischke, 1880). The presence of Diadegma ruficeps (Holmgren, 1860) in Belgium is confirmed.
Libert et al. (Wed,) studied this question.