Liadoxyelini Rasnitsyn, 1966

Zheng, Yan, Hu, Haiyan, Chen, Dong, Chen, Jun, Zhang, Haichun & Rasnitsyn, Alexandr P., 2021, New fossil records of Xyelidae (Hymenoptera) from the Middle Jurassic of Inner Mongolia, China, European Journal of Taxonomy 733 (733), pp. 146-159 : 149

Tribe Liadoxyelini Rasnitsyn, 1966

Type genus

Liadoxyela Martynov, 1937 .

Remarks

This tribe was proposed for four genera ( Liadoxyela Martynov, 1937 , Kirghizoxyela Rasnitsyn, 1966 , Anomoxyela Rasnitsyn, 1966 , and Lydoxyela Rasnitsyn, 1966 ) and five species from Jurassic and Early Cretaceous of Siberia and Central Asia, based on a set of diagnostic characters including short 1m-cu (about half as long as 3-Cu) as distinguishing it from Xyelini Newman, 1834 , the only other tribe in subfamily Xyelinae ( Rasnitsyn 1966) . The next revision of Xyelidae and Symphyta in general ( Rasnitsyn 1969) added another diagnostic feature, 1-Rs not longer than 1-M. One more genus ( Orthoxyela Rasnitsyn, 1983 ) and two species from the Jurassic of Siberia have been added to the tribe since ( Rasnitsyn 1983). Much later three further genera ( Platyxyela Wang et al., 2012 , Cathayxyela Wang et al., 2014 , Aequixyela Wang et al., 2014 ), each with one species from the Middle Jurassic of China, have been added to the tribe, even though not without confusion ( Wang et al. 2012, 2014). The first genus was described in Macroxyelinae Ashmead, 1898 but later listed under Liadoxyelini Rasnitsyn, 1966 ( Wang et al. 2014: table 1). Judging from their descriptions and the table 1, Cathayxyela and Aequixyela were equally described as members of Liadoxyelini , but this was under the title Xyelini which we consider a lapsus calami. We agree with the interpretation of Platyxyela and Cathayxyela as members of Liadoxyelini . However, Aequixyela differs from other Liadoxyelini considerably in having 1-Rs scarcely longer than 1-M, 1m-cu distinctly longer than half 3-Cu, pterostigma distinctly inflated (often in Xyelini but never in Liadoxyelini ), and unlike all Xyelidae , ovipositor very short and narrow. Unusual is also the very short antennal flagellum, only comparable with that in living Macroxyelini Ashmead, 1898 . The position of the latter genus needs special consideration: for the moment we consider it as Xyelinae incertae tribus.