Pinicola julii obscura Strobl, 1895:277 - As Xyela obscura: - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 1. Symphyta and Apocrita (Parasitica). Smithsonian Institution Press, Washington D.C. 1-1198. (distribution); Blank, S.M. et al., 2001Blank, S.M., S. Deters, M. Drees, M. Jänicke & E. Jansen 2001. Symphyta. In: Dathe, H., A. Taeger & S.M. Blank (Ed.). Verzeichnis der Hautflügler Deutschlands (Entomofauna Germanica, Band 4). 8-28. (distribution), 8 (distribution).
Xyela japonica Rohwer, 1910:99 - Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 1. Symphyta and Apocrita (Parasitica). Smithsonian Institution Press, Washington D.C. 1-1198.:8 ( listed as synonym of Xyela obscura (Strobl, 1895)).
Xyela pini Rohwer, 1913:267, ♂♀. Holotype, Call, Texas, February 28, 1905 (U.S.N.M., No. 15377, leg. W.F. Fiske). - Muesebeck et al., 1951Muesebeck, C.F.W., K.V. Krombein & H.K. Townes 1951. Hymenoptera of America north of Mexico - Synoptic catalog. U.S. Dept. Agr. Monog. 2:1-1420. (distribution); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 1. Symphyta and Apocrita (Parasitica). Smithsonian Institution Press, Washington D.C. 1-1198.:8 ( listed as synonym of Xyela obscura (Strobl, 1895)).
Xyela slossonæ Rohwer, 1913:270, ♂♀. Holotype, Biscayne Bay, Florida (U.S.N.M., No. 15383, leg. A.T. Slosson). - Muesebeck et al., 1951Muesebeck, C.F.W., K.V. Krombein & H.K. Townes 1951. Hymenoptera of America north of Mexico - Synoptic catalog. U.S. Dept. Agr. Monog. 2:1-1420. (distribution); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 1. Symphyta and Apocrita (Parasitica). Smithsonian Institution Press, Washington D.C. 1-1198.:8 ( listed as synonym of Xyela obscura (Strobl, 1895)).
Xyela similis Rohwer, 1913:271, ♂. Holotype ♂, Call, Texas, February 28, 1905 (U.S.N.M., No. 15385, leg. W.F. Fiske). - Muesebeck et al., 1951Muesebeck, C.F.W., K.V. Krombein & H.K. Townes 1951. Hymenoptera of America north of Mexico - Synoptic catalog. U.S. Dept. Agr. Monog. 2:1-1420. (distribution); Krombein et al., 1979Krombein, K.V., P.D. Hurd, D.R. Smith & B.D. Burks 1979. Catalog of Hymenoptera in America North of Mexico. Volume 1. Symphyta and Apocrita (Parasitica). Smithsonian Institution Press, Washington D.C. 1-1198.:8 ( listed as synonym of Xyela obscura (Strobl, 1895)).