Checklist of British and Irish Hymenoptera - Sawflies, ' Symphyta' Author Liston, Andrew D. Author Knight, Guy T. Author Sheppard, David A. Author Broad, Gavin R. Author Livermore, Laurence text Biodiversity Data Journal 2014 2 1168 1168 http://dx.doi.org/10.3897/BDJ.2.e1168 journal article http://dx.doi.org/10.3897/BDJ.2.e1168 1314-2828-2-1168 Arge pagana (Panzer, 1797) Tenthredo pagana Panzer, 1797 Hylotoma? stephensii (Leach, 1817, Hylotoma ) Distribution England, Wales Notes Arge stephensii differs very markedly, in the extreme development of pale body markings, from all known W. Palaearctic populations of Arge pagana . Traditionally, Arge stephensii has been regarded as an endemic British subspecies of Arge pagana . Further studies [here a DNA analysis might offer good clues] are definitely required. The possibility cannot be excluded that Arge stephensii is a separate species originally introduced from the E. Palaearctic or Oriental Regions, where Arge is both extremely species-rich and poorly investigated.