Grazie, Adriano!
C'è da dire che la letteratura in merito a questi generi non è proprio abbondantissima ed esauriente. Ad esempio, su
faunaitalia.it è segnalata solo una specie appartenente al genere
Stethynium, tuttavia non so quanto sia aggiornata ed attendibile questa checklist. Inoltre, bisogna considerare che in
Munro & al. 2011 il genere
Stethynium è trattato come avente 5 tarsomeri. Non mi è ancora chiaro come sia possibile che un dato genere risulti avere 4 tarsomeri per alcuni autori e per altri 5. Comunque, In base alle chiavi identificative alle pagine 75 e 79 del
lavoro da te citato, e considerando che il numero di tarsomeri NON è l'unico carattere distintivo del genere
Stethynium, sembrerebbe trattarsi proprio di
S. triclavatum.
E. Pricop 2013, pp.75-79 ha scritto:
Stethynium: Head and mesosoma not flattened dorsoventrally; head higher than long, frons and face are vertical and straight (Figure 5i); mandibles normal developed and overlapping (mandibles with 4 teeth); clava evidently divided obliquely into 3 segments (Figures 5c, 5h); almost all the funicular segments are much longer than wide (Figure 5h); scape with transversal to oblique lines or folds (transversal striation-like lines) and at most with 2 longitudinal lines of setae (Figure 5g); the cubital line of hairs more or less evident (Figure 5f); legs normal developed, not robust.
Stethynium triclavatum: body not flat (Figure 5k), antennal clava with three segments (Figures 5c, h), forewings broad (Figure 5f).
Munro & al. 2011, p.21 ha scritto:
Although there was some early doubt about the monophyly of Mymaridae, the family has been well substantiated based on morphology and molecular evidence. Huber noted that the higher classification of Mymaridae is unstable, and as per the advice of Huber and Triapitsyn, Mymaridae sff have been abandoned and gg grouped according to their number of tarsal segments. Gibson was the first to propose morphological evidence that Mymaridae might be the sister group of the remaining Chalcidoidea, but without firm resolution. Mymaridae were found to be monophyletic in all analyses with very strong support. The 4-segmented tarsi group, represented by the genera Borneomymar, Gonatocerus, Litus and Ooctonus, were consistently monophyletic across all analyses with moderate to strong support. The remaining gg, Acmopolynema, Anagrus, Anaphes, Australomymar, Ceratanaphes, Erythmelus, Eubroncus, Mymar and Stethynium, formed the 5-segmented tarsi group. This group is supported in most analyses (88% of likelihood analyses), with moderate to strong BS support only when RAAs were included. There was no support for Mymarinae or Alaptinae. Eubronchinae were monophyletic, but these were represented by only a single genus. Mymaridae were strongly supported as the sister group of the remaining Chalcidoidea in all analyses.
REFERENCESE. Pricop 2013: Identification key to European genera of the Mymaridae (Hymenoptera Chalcidoidea), with additional notes.
PDFJ.M. Heraty & al. 2013: A phylogenetic analysis of Chalcidoidea.
PDFJ.B. Munro & al. 2011: A molecular phylogeny of Chalcidoidea.
PDFJ.T. Huber 1987: Review of the non-Australian spp of
Stethynium.
PDFhttp://www.faunaitalia.it/checklist/inv ... ridae.html