Orthocladius ticinoi Rossaro & Prato, 1991

Bruno Rossaro & Carlotta Casalegno, 2001, Description of the pupal exuviae of some species belonging to Orthocladius s. str. van der Wulp, 1874 (Diptera: Chironomidae: Orthocladiinae), with a new key to species of West Palaearctic region, Zootaxa 7, pp. 1-20 : 14-15

Orthocladius ticinoi Rossaro & Prato, 1991

O. ticinoi Rossaro & Prato, 1991

Orthocladius Pe 7 Langton, 1984: 155 ( Langton 1991: 190 a tentative synonym)

nec O. glabripennis Goetghebuer, 1921 , sensu Rossaro 1991

DESCRIPTION. See Rossaro & Prato (1991, Fig. 17, 18). Colour pale transparent. Frontal warts not developed. Thoracic horn slender at apex, 240­420 m long, with points less developed than in O. obumbratus . Thorax moderately rough. Pedes spurii B developed. On T II only posterior point field present. TIII with posterior points not extended laterally beyond apical points. Points on TIII­VI limited to a central trapezoidal area; there is a sudden drop in point size to antero­lateral points. Posterior points on TIII­VI and apical points on TIII­V more developed than the anterior ones, onT IV ­VI anterior points more developed than the median ones. SII­IV with more or less extended fields of very small grouped points. Pedes spurii A present on S IV­VII. Lateral setae: 1 on segment I, 3 on segments II­VI, 4 on segment VII and 5 on segment VIII. Anal lobes with small colourless apical taeniate extensions of cuticle, at most 30 m long, with the shape of small colourless teeth (Fig. 2.3), laterally in addition very small apical extensions may be present. Anal macrosetae 225­265 m long, anal lobes 325­420 m long, 350­490 m wide.

COMMENTS. The species can be easily separated from O. obumbratus , in which well sclerotized extensions of cuticle at the tips of anal lobes, resembling spurs, are observed. Rossaro (1991) synonymized O. ticinoi with O. glabripennis (= Orthocladius Pe 5), because of the presence of small and colourless teeth ( Langton & Cranston 1991), but apical taeniate extensions of cuticle apparently are always absent in O. glabripennis and there is no variation within the species in this respect, O. glabripennis is a lentic species, O. ticinoi is restricted to running waters besides this. The conclusion is that specimens with small colourless apical taeniate extensions of cuticle do not belong to O. glabripennis , but to O. ticinoi , which is a separated species. According to Langton (1991) description, O. ticinoi be identical with Orthocladius Pe 7 Langton 1984: 155.

MATERIAL EXAMINED: FRANCE: GARONNE river, 10/3/1997, 1 Pex. ITALY: LOMBARDIA: Brembo river, 26/2/2001, 1 Pex; Serio river, Ricengo, 18/2/2001, 1 Pex; 23/3/2000, 1 Pex; Ticino river, Oleggio, 16/2/1995, 1 Pex; Boffalora, 11/1/1981, 1 Pex, 25/ 1/1981, 1 Pex, 1/5/1981, 1 Pex, 11/2/1993, 1 Pex; Castelletto, 14/2/2001, 9 Pex; 5/3/2001, 1 Pex. EMILIA ROMAGNA: Po river, Caorso, 12/4/1977, 1 Pex; 13/12/1983, 1 Pex; Chiavenna stream, tributary of Po river, 10/4/1979, 1 Pex. ABRUZZO: Aterno river, Coppito, 28/2/1992, 1 Pex.