Reference

Herbert Zettel, Toshko Ljubomirov, Florian M. Steiner, Birgit C. Schlick-Steiner, Giselher Grabenweger, Heinz Wiesbauer (2004): The European ant hunters Tracheliodes curvitarsus and T. varus (Hymenoptera: Crabronidae): taxonomy, species discrimination, distribution, and biology. – Myrmecological News = Myrmecologische Nachrichten – 006: 39 - 47.