Revision of type and non-type material assigned to the genus Orthocladius by Goetghebuer (1940 - 1950), deposited in the Royal Belgian Institute of Natural Sciences (Diptera: Chironomidae) Author Magoga, Giulia ) &) &) Università degli Studi di Milano, Dipartimento di Scienze Agrarie e Ambientali (DISAA), via Celoria 2, I 20133, Milano, Italia; e-mails: giulia. magoga @ unimi. it; matteo. montagna @ unimi. it Author Montagna, Matteo ) &) &) Università degli Studi di Milano, Dipartimento di Scienze Agrarie e Ambientali (DISAA), via Celoria 2, I 20133, Milano, Italia; e-mails: giulia. magoga @ unimi. it; matteo. montagna @ unimi. it Author Marziali, Laura ) &) Water Research Institute, National Research Council (IRSA-CNR), Via del Mulino 19, I 20861 Brugherio (MB), Italy; e-mail: marziali @ irsa. cnr. it Author Rossaro, Bruno ) &) Università degli Studi di Milano, Dipartimento di Scienze per gli Alimenti, la Nutrizione e l’Ambiente (DeFENS), Via Celoria 2, I 20133 Milan, Italy; e-mail: bruno. rossaro @ unimi. it Author Disaa text Acta Entomologica Musei Nationalis Pragae 2017 Acta. Ent. Mus. Natl. Pragae 2017-12-31 57 2 723 749 http://dx.doi.org/10.1515/aemnp-2017-0097 journal article 10.1515/aemnp-2017-0097 0374-1036 5318416 638421F2-985E-43CC-8438-E871F96B1DB8 Orthocladius ( Symposiocladius ) ruffoi Rossaro & Prato, 1981 Orthocladius ruffoi Rossaro & Prato, 1981: 60 . Material examined. 1♁ in isinglass now mounted on slide, labelled:‘ Rheorthocladius sp.A . 416 // Heusden 20.3. 16 M. Goetghebuer // Non-type, type locality Ploen ( GERMANY ), 1937 Humphries, P.S.Cranston, 1975 // R .I.SC.N.B. 18.073 / Coll. et det. M. Goetghebuer’. Figs 63‒68. Pseudorthocladius sp. 63 ‒ eyes, 64 ‒ acrostichals, 65 ‒ pulvilli, 66 ‒ wing squama, 67 ‒ anal point, 68 ‒ inferior volsella. Comments. The genus Rheorthocladius was created by THIENEMANN (1935) to include species of Orthocladius on the basis of their metamorphic stages (pupal exuviae). This male is associated with pupal exuviae labelled as Rheorthocladius sp. A , deposited in the Zoologische Staatssammlung München (ZSM). The last antennal flagellomere is 1066 m long, the total length of the remaining flagellomeres is 379 m, AR = 2.81; Pm3 length 151 m, Pm4 length 116 m, length ratio Pm3/Pm4 = 1.30; dorsocentrals 13; tergite IX with 13 setae. Hypopygium as in O. ( S. ) ruffoi (see ROSSARO et al. 2003 ) with phallapodeme distinctly curved apically. A comparison with the holotype allows the assignment of the studied specimen to O. ( S. ) ruffoi , even though in the holotype of O. ( S. ) ruffoi the length ratio Pm3/Pm 4 is near to 1, instead of 1.30 ( ROSSARO et al. 2003 ).