. Diptera Danica: genera and species of flies hitherto found in Denmark. Diptera. 194 Orthorrhapha brachycera. with a few bristles above, but none below; middle tibiae with two rows of bristles above and one ventral bristle; hind tibiae likewise with two dorsal rows, and with some very small ventral bristles and one stronger towards the apex. Wings almost hyaline; veins blackish brown or black; discal vein with an exceedingly slight bend and only. Fig. 58. Wing of H. aerosus d- very slightly converging towards the cubital vein, almost parallel with it; posterior cross-vein about perpendicular,
. Diptera Danica: genera and species of flies hitherto found in Denmark. Diptera. 194 Orthorrhapha brachycera. with a few bristles above, but none below; middle tibiae with two rows of bristles above and one ventral bristle; hind tibiae likewise with two dorsal rows, and with some very small ventral bristles and one stronger towards the apex. Wings almost hyaline; veins blackish brown or black; discal vein with an exceedingly slight bend and only. Fig. 58. Wing of H. aerosus d- very slightly converging towards the cubital vein, almost parallel with it; posterior cross-vein about perpendicular, not oblique as in assimi- lis; axillary lobe moderately developed. Squamulae yellow, with a black fringe. Halteres pale yellow. Female. Epistoma broad, grey. Antennae shorter than in the male, third joint short triangular. Length 3—3,5 mm. This species is very similar to assimilis^ but in the male it is at once known by the black epistoma; the female is more difficult to distinguish, but it will be known by the quite yellow hind tibiae, and by the clearer wings with the more parallel cubital and discal vein and the more perpendicular posterior cross-vein; when the front and hind femora are blackish striped, this will also be a distinguishing character. The two species asshnilis and aerosus will easily be known from metallicus by the size and the character from the venation given in the table; the females of these two species are on the other hand also similar to the females of celer and brevicornis, they may however be distinguished by .the character in the latter species, that the basal part of the costa has a thickening, which is, to be sure, slight, but on close examination distinctly to be seen. H. aerosus is rather common in Denmark; Gharlottenlund, Or- drup Krat, Dyrehaven, Bollemosen, Ryget Skov at Farum So, Eille- r0d and Praestevang at Hillerod, Tisvilde, Faxe Ladeplads; on Funen at Middelfart and Veflinge; in Jutland at Laven and Sminge near Silkeborg, Randers, Rav
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Keywords: ., bookauthorlu, bookcentury1900, bookdecade1900, booksubjectdiptera
