Micradelinae incertae sedis new placement, 1926

Burks, Roger, Mitroiu, Mircea-Dan, Fusu, Lucian, Heraty, John M., Jansta, Petr, Heydon, Steve, Papilloud, Natalie Dale-Skey, Peters, Ralph S., Tselikh, Ekaterina V., Woolley, James B., van Noort, Simon, Baur, Hannes, Cruaud, Astrid, Darling, Christopher, Haas, Michael, Hanson, Paul, Krogmann, Lars & Rasplus, Jean-Yves, 2022, From hell's heart I stab at thee! A determined approach towards a monophyletic Pteromalidae and reclassification of Chalcidoidea (Hymenoptera), Journal of Hymenoptera Research 94, pp. 13-88 : 13

Micradelinae incertae sedis new placement

Micradelini Wall, 1972. Type genus: Micradelus Walker, 1834. Treated as Micradelinae by Vago (2006).

Diagnosis.

Antenna with 10 or 11 flagellomeres, including 3 or 4 clavomeres. Eyes slightly ventrally divergent. Clypeus transverse, with transverse subapical groove. Labrum exposed, well-sclerotized, subrectangular with marginal setae in a row (Fig. 75 ). Mandibles with 2 teeth or with a small 3rd dorsal tooth (Fig. 75 ). Subforaminal bridge with postgena separated by lower tentorial bridge except for a small postgenal bridge dorsal to the hypostoma; posterior surface of head without (Fig. 76 ) postgenal lamina or postgenal groove. Pronotum transverse in dorsal view. Mesoscutellum with frenum reduced, with frenal arm laterally but sometimes hardly separated from marginal rim of mesoscutellum; axillular sulcus present. Mesopleural area without expanded acropleuron, without pits; mesepimeron extending over anterior margin of metapleuron; one mesofurcal pit present. Fore wing marginal vein subequal to stigmal vein in length; uncus elongate. All legs with 5 tarsomeres; protibial spur stout and curved. Metasoma with syntergum, therefore without epipygium.

Discussion.

The former tribe Micradelini was treated as a subfamily by Vago (2006) and we preserve that rank here, although we remove it from Pteromalidae based on both molecular and morphological data (Cruaud et al., submitted). While Micradelinae are very similar to Herbertiidae in body shape, they only occasionally form a monophyletic group and Micradelinae are particularly unstable in phylogenetic placement.

Morphologically, Micradelinae strongly resemble Herbertiidae and the incertae sedis genus Rivasia Askew & Nieves-Aldrey in habitus and other features. The basitarsal comb of Micradelus Walker is reduced and difficult to evaluate, although it may be oblique like that of Herbertiidae . Herbertiidae differ from Micradelinae in having a much shorter stigmal vein relative to the marginal vein, in lacking an axillular sulcus, in lacking the postgenal groove and postgenal sulcus on the back of the head, and in having 2 mesofurcal pits instead of the single pit of Micradelinae . Rivasia is very similar to Micradelinae in most features, differing in having a more elongate body including the pronotum, and in having metallic green coloration instead of the short, stout body and brownish coloration of Micradelinae . Eunotidae may appear similar to Micradelidae when comparing lists of features, but in practice are easily distinguished in their different habitus and in having a short fore wing uncus.

Figures

Figures 73 - 78. 73, 74 Callimomoides sp. (Louriciinae, incertae sedis) 73 mesosoma dorsal view 74 extremity of metasoma, elongated syntergum 75, 76 Micradelus acutus Graham (Micradelinae, incertae sedis) 75 head frontal view 76 head posterior view 77 Neapterolaelaps sp. (Neapterolelapsinae, incertae sedis): antenna 78 Pseudoceraphron albifrons (Boucek) (Neapterolelapsinae, incertae sedis): head posterior view.