Nematode-induced demasculinisation of Dolichopus males (Diptera: Dolichopodidae) Author Kahanpää, Jere text Zootaxa 2008 1689 51 62 journal article 10.5281/zenodo.180614 549e79e9-bf81-4d14-9633-8af319a5c9dd 1175-5326 180614 Dolichopus lepidus Staeger, 1842 Dolichopus lepidus Staeger, 1842 : 36 Dolichopus cruralis Wahlberg, 1850 : 219 syn. nov. Dolichopus lapponicus Becker, 1917 : 141 syn. nov. Demasculinised males examined: MZH — Finland , 1ɗ Tb: Saarijärvi, 18.vi.1942 , R. Krogerus; 1ɗ Ta: Kangasala, R. Frey, id 439; 1ɗ Li: Ivalo, W. Hellén, id 858; 1ɗ Ks. Ti?, 15.vii.1935 , R. Krogerus, id 223. Russia , 1ɗ Ks: Salla, R. Krogerus, id 978; 2ɗ Ks: Salla, R. Frey, id 636 & 570; 1ɗ Ks: Kuusamo, R. Frey, id 650; Ks: Kuusamo, Kontkanen, id 710; 1ɗ Ks: Kuusamo, J. Sahlberg, id 121.; 3ɗ Trifona, W. Hellén, id 797, 857 & 886; 1ɗ Salmijärvi. R. Frey, id. 1490; 1ɗ Ks: Kuusamo, 23.vii. 1934 , R. Krogerus, id 784. Coll. JK — Finland , 1ɗ Ks: Posio, Soidinkangas (73348:35544), 8.vii.2006 , J. Kahanpää, id jka06-01427; 1ɗ Ks: Kuusamo, Sohramonlampi (73302:33057), 7.vii.2006 , J. Kahanpää, id jka06-01579; 1ɗ Ks: Kuusamo, Antinvaara (73390:36039), 7.vii.2006 , J. Kahanpää, id jka06-01634; 1ɗ Tb: Saarijärvi, Riuttalampi (69605:34116), 19.vii.2003 , J. Kahanpää, 1ɗ Li: Inari, Lauttoselkä (7618207:3548944), 22.vii.–27.viii.2004 , J. Salmela; 5ɗ Obb: Tervola, Hirviaapa (7347499:3418464), 28.vi.–2.viii.2004 , J. Salmela & J. Ilmonen; 1ɗ Li: Inari, Mustajuurakkojärvi (7619453:3554246),7/2004, J. Salmela; 2ɗ Obb: Tervola, Yrttijänkä (7346833:3407825), 28.vi.–2.viii.2004 , J. Salmela & J. Ilmonen. Dolichopus cruralis is the best known and most common of the demasculinised forms. It differs from D. lepidus by the small male genitalia, a broader face, weakly developed or missing pterostigma and simple hind legs ( Wahlberg 1850 ). D. cruralis is the only demasculinised male for which a female counterpart has been described ( Stackelberg 1930 ). Stackelberg (1930) , Parent (1938) , Negrobov (1991) and Yang et al. (2006) treated D. cruralis as a valid species. Nearly all examined males of D. cruralis were found to be parasitised. All characters separating D. cruralis from D. lepidus are typical for demaculinised Dolichopus males. D. cruralis Wahlberg, 1850 is here synonymised with D. lepidus Staeger, 1842 . The colour pattern of the hind tibia, proposed as a diagnostic character for females of D. cruralis by Stackelberg (1930) , is commonly found in D. lepidus females. The colour of the hind tibia of females of D. lepidus is very variable and it has no value as a diagnostic feature. Some singly parasitised males of D. lepidus have genitalia of almost normal size and shape. They agree well with the description of D. lepidus var. microstigma Stackelberg, 1930 . Dolichopus lapponicus Becker was synonymised with D. cruralis by Stackelberg (1930) . As a corollary of the synonymy of D. cruralis and D. lepidus , D. lapponicus Becker, 1917 must also be synonymised with D. lepidus Staeger, 1842 .