Distribution in Iran. Ilam (Ghahari et al. 2011 d, Khajeh et al. 2014 as Syndalis maxima), Qazvin (Ghahari et al. 2011 b as D. concinna (Haliday 1838)), Iran (no locality cited) (Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b).
Distribution outside Iran. Afghanistan, former Czechoslovakia, Faeroe Islands, Iceland, Ireland, Mongolia, Netherlands, Poland, Russia, Sweden and Tunisia (Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b), Austria and Germany (Fischer 1973 a; Francés and Jiménez 1989 b as Synaldis maxima; Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b), Bulgaria and Israel (Papp 2011–2012 as S. maxima), Greece (Papp 2007 a as D. concinna; Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b), Hungary (Fischer 1973 a, Francés and Jiménez 1989 b as S. maxima; Papp 2008; Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b), Italy (Papp 2011–2012 as S. maxima; Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b), Madeira Islands (van Achterberg and Aguiar 2009), Spain (Francés and Jiménez 1989 b as S. maxima; Fischer et al. 2008), United Kingdom (Broad et al. 2012; Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b), former Yugoslavia (Francés and Jiménez 1989 b as S. maxima; Yu et al. 2012; Peris-Felipo 2013; Peris-Felipo et al. 2014 b).
Host records. Fannia canicularis (L., 1761) (Diptera: Fannidae), Vespula vulgaris (L., 1758) (Hymenoptera: Vespidae) (Yu et al. 2012).