Eusandalinae Fusu, new subfamily

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

Eusandalinae Fusu, new subfamily

Type genus.

Eusandalum Ratzeburg, 1852.

Diagnosis.

Antennal flagellum with 9 flagellomeres, clava undivided. Eyes ventrally divergent. Clypeus with truncate apical margin. Labrum subquadrate, exposed. Subforaminal bridge with median area flanked by elongate posterior tentorial attachments; postgenal bridge externally separates the lower tentorial bridge from the hypostomal carina; postgenal groove and postgenal lamina absent. Anterolateral mesoscutal corners projecting shoulder-like on either side of the pronotum (a feature shared with Calosotinae sensu stricto). Notauli superficial and convergent, and except for Archaeopelma , ending about halfway across mesoscutum (Fig. 112 ). Axilla approximated ( Archaeopelma Gibson and Paraeusandalum Gibson) or widely separated ( Eusandalum Ratzeburg, Licrooides Gibson and Pentacladia Westwood) medially. Axillular groove or carina absent. Frenum absent. Acropleuron expanded and forming the largest surface of the mesopleuron, either comparatively small and not reaching metapleuron and metacoxa ( Archaeopelma , Licrooides ) or occupying most of the visible part of the mesopleuron and extending to the metapleuron (the other three genera). All legs with 5 tarsomeres; protibial spur stout and curved; basitarsal comb longitudinal; ventral membranous area anterior to mesocoxal attachment present; mesotibial spur stout except only slightly thickened in Archaeopelma . Fore leg with protibial dorsal spicules (except in Licrooides ). Mesotarsus almost never with row of pegs along both sides, the exception being Licrooides : with spine-like setae on both antero- and posteroventral margins ( Archaeopelma ) or a row of pegs on posteroventral margin and a row of spine-like setae along anteroventral margin (remaining three genera). In Licrooides there are robust spines on both margins that almost appear as pegs. Metasoma in females with separate Mt8 and Mt9, hence without syntergum ( Eusandalum ) or with Mt8 and Mt9 fused but delimited by a transverse suture between cerci ( Archaeopelma ) or below each cercus (remaining genera; Fig. 113 ). Sexual dimorphism reduced, limited mainly to primary sexual features and antennal structure.

Discussion.

Eusandalinae new subfamily were treated until now as part of Calosotinae , however in next-generation molecular analyses (Cruaud et al., submitted) they were never recovered as monophyletic with the other Calosotinae . Instead, a reduced group of Calosotinae that includes Balcha Walker, Calosota Curtis and Tanythorax Gibson ( Calosotinae sensu stricto) are sister to Heydenia ( Heydeniidae ) in all final analyses and closer to Eupelminae than to Eusandalinae . Eusandalinae are part of the same large clade containing also the Eupelminae and Calosotinae , but the three Eupelmidae subfamilies never form a monophyletic group since the clade also includes Ditropinotellinae , Heydeniidae and Solenurinae ; Eusandalinae are the basal group. Beside the three genera included in these molecular analyses (Cruaud et al., submitted) we also include in Eusandalinae Archaeopelma and Licrooides based on a UCE analysis with a larger sampling (unpublished data). A possibly biphyletic Calosotinae sensu lato was also recognised by Gibson (1989), however with Licrooides hypothesized as closer to Calosota and allied genera and not to Eusandalum , and Archaeopelma as the most basal lineage of all Calosotinae . From the morphologically close Calosotinae sensu stricto, the Eusandalinae differ mainly in having an undivided clava, convergent notauli, scutellum without axillular groove or carina, mesotarsus almost never with two fully developed rows of pegs and a metasoma with incompletely fused or independent Mt8 and Mt9. In Calosotinae : clava with three clavomeres, notauli present as paramedially parallel lines, axillular groove present and continuing seamlessly with the scuto-scutellar suture and as a result scutellum with a carinated groove extending from base to apex, mesotarsus with a row of pegs on either side, and Mt8 and Mt9 completely fused to form the syntergum. However, all the characteristic features of Eusandalinae are either plesiomorphic or homoplastic. A thorough comparative analysis of all these characters can be found in Gibson (1989).

Figures

Figures 109 - 114. 109, 110 Gastracanthus acutus (Kamijo) (Pteromalidae, Trigonoderinae) 109 lower face frontal view 110 mesosoma dorsal view 111 Cales noacki Howard (Calesidae): mesosoma lateral view 112 Eusandalum flavipenne Ruschka: mesosoma dorsal view 113 Pentacladia elegans Westwood: Mt 8 and Mt 9 fused, but delimited by an oblique suture below cercus 114 Chromeurytoma sp. (Megastigmidae, Chromeurytominae): head and mesosoma dorsal view.