Buffingtonella Lobato-Vila & Pujade-Villar gen. nov.

(Figure 2)

urn:lsid:zoobank.org:act: B76257BC-095D-43AA-95C8-1DA2ADF3FEFD

Type species. Ceroptres politus Ashmead, 1896, by present designation and monotypy.

Etymology. Named in honor of Dr. Matthew L. Buffington (Systematic Entomology Laboratory, National Museum of Natural History, Smithsonian Institution, Washington D.C., USA), who has widely contributed to the knowledge of Cynipoidea .

Gender. Female.

Diagnosis. Buffingtonella differs from Ceroptres by the total absence of vertical carinae on the lower face running from the inner ventral margin of the toruli, and by the absence of a pubescent depressed area more or less extending between or below the toruli (Fig. 2e), whereas a depressed area is always present, even if the carinae are very short or almost absent, in Ceroptres (for example, Figs 11a, d; 12a; 13a; 14a; 15a; 16a; 17a); by having the first metasomal tergum ring-shaped and longitudinally sulcate like most members of Synergini (inset image in Fig. 2c; 2d, k), whereas this tergum is always formed as a dorsal smooth crescent-shaped scale in Ceroptres (for example, Figs 12f; 13h; 14e; 15i; 16l; 17i); and by having propodeal carinae straight in the anterior 1/3 and clearly divergent and curved in the posterior 2/3, being also somewhat branched distally (Fig. 2j), whereas these carinae are always uniformly straight or very slightly curved over their whole length in Ceroptres (for example, Figs 12e; 13d; 14f; 15g; 16j; 17k).

Description. Female antenna 12-segmented and subclavate (Fig. 2i), male antenna 15-segmented and filiform (Fig. 2h). Lower face with a few weak striae radiating from sides of clypeus, including one that reaches the toruli on the outside rim (Fig. 2e). Malar space short. Frontal carinae absent. Head and mesoscutum weakly sculptured, finely coriaceous to alutaceous (Fig. 2c, d, f, g). Pronotum without lateral carinae (Fig. 2a, b). Dorsal part of pronotal plate complete, with two distinct foveae. Notauli incomplete (Fig. 2c, d, g). Mesopleuron completely smooth and shiny (Fig. 2a, b). Propodeal carinae straight in the anterior 1/3 and clearly divergent and curved in the posterior 2/3, being also somewhat branched distally (Fig. 2j). First metasomal tergum ring-shaped and weakly longitudinally sulcate (inset image in Fig. 2c; 2d, k). Second metasomal tergum (T2) short and free, not overlapped with the third, in both sexes (Fig. 2 a–d, k) and with sparse pilosity anterolaterally, not forming a patch. Third metasomal tergum (T3) without punctures and not dorsodistally incised. Radial cell of the forewings closed (Fig. 2l). Tarsal claws bidentate, with a basal lobe.

Remarks. From a morphological point of view, there is no doubt that Buffingtonella constitutes a genus distinct from Ceroptres . Despite the above mentioned differences between these genera, we consider that Buffingtonella belongs to Ceroptresini by having the second metasomal tergum small and free, not overlapped with the third, in both sexes, which is an exclusive trait of this tribe, among other non-exclusive morphological traits that are typical of Ceroptres (like the number of antennomeres and the subclavate shape of antennae in females, the presence of weak striae radiating from sides of clypeus, the weak sculpture of both head and mesosoma, the absence of frontal carinae or the presence of conspicuous pilosity in the second metasomal tergum). However, the possibility that this new genus actually belongs to a different tribe, or even to a new tribe of oak gall wasps, cannot be dismissed: (i) propodeal carinae are always uniformly straight or slightly curved in their whole length in Ceroptres and among all Synergini, while in Buffingtonella these are straight in the anterior 1/3 and clearly divergent and curved in the posterior 2/3; this character state is similar to that present in some Cynipini, but we are, nevertheless, of the opinion that Buffingtonella belongs to this tribe based on its biology and according to other morphological traits that are distinct from those of Cynipini; (ii) a more or less extended depressed area between or below the toruli is always present in Ceroptres even when the vertical carinae are very short or absent, while it is totally absent in Buffingtonella; this depressed area is absent in Synergini, but all genera within this tribe have the second metasomal tergum fused with the third tergum forming one large sclerite in both sexes; (iii) the first metasomal tergum is always a smooth crescent-shaped scale in Ceroptres, while in Buffingtonella it is ring-shaped and weakly sulcate like most of Synergini (except Rhoophilus); however, and as it has been stated above, Buffingtonella cannot belong to Synergini . Molecular analyses will be needed in order to assess whether Buffingtonella belongs to a new tribe of Cynipidae, which is currently not feasible due to the lack of fresh material. For now, we consider that Buffingtonella is best placed within Ceroptresini according to the morphological traits outlined above.