Heydeniidae new status, new placement, 1923

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

Heydeniidae new status, new placement

Heydenini Hedqvist, 1961. Type genus: Heydenia Förster, 1856. Spelling corrected to Heydeniini by Bouček (1988).

Diagnosis.

Antenna with 10 or 11 flagellomeres, including 3 clavomeres. Eyes ventrally divergent. Clypeus without transverse subapical groove. Labrum exposed or hidden behind clypeus, sclerotized. Mandibles with 3 teeth. Pronotum expanded laterally and forming a subrectangular or laterally expanded structure from dorsal view (Fig. 67 ). Prepectus long, with large dorsal and ventral surfaces. Mesoscutellum either without a frenum, or with frenum laterally indicated by a frenal arm, with or without axillular sulcus (Fig. 68 ). Mesopleural area with acropleuron slightly expanded but occupying less than half its surface; mesepimeron not extending over anterior margin of metapleuron. All legs with 5 tarsomeres; profemur strongly (Fig. 69 ) or only mildly expanded; protibial spur stout and curved; basitarsal comb longitudinal. Metasoma with syntergum, therefore without epipygium, although terga not well-sclerotized and often difficult to assess.

Discussion.

Some species of Heydeniidae are distinctive and resemble Ooderidae , while more generalized species are considerably more difficult to recognize. Ooderidae differ in having multiple rows of spine-like structures on the ventral surface of the always strongly expanded profemur. Heydeniidae have instead at most a single row of crest-like structures ventrally on the profemur. Otherwise, the ventrally elongate prepectus of Heydeniidae is distinctive. When the profemur is not strongly expanded and the pronotum is relatively short and not tent-like, species of Heydenia Förster can be more difficult to recognize. Given the presence of a convex mesoscutellum with a weakly distinct or indistinct frenum and ventrally divergent eyes, generalized Heydeniidae may be confused with Cleonymidae or Lyciscidae , both of which have a much shorter prepectus ventrally.

Figures

Figures 67 - 72. 67 - 69 Heydenia longicollis (Cameron) (Heydeniidae) 67 mesosoma dorsal view 68 mesosoma lateral view 69 fore leg 70, 71 Kerya antennalis Boucek (Keryinae, incertae sedis) 70 head frontal view and antenna 71 mesosoma lateral view 72 Callimomoides sp. (Louriciinae, incertae sedis): head frontal view.