Onesia. 



159 



Geographical distribution: — Europe down into Austria; at 

 present not known north of Denmark. 



5. O. caerulea Meig. 



1826. Meig. Syst. Beschr. V, 63, 23 (Musca). — 1845. Zett. Dipt. Scand. 

 IV, 1310, 30 (Sarcophaga). — 1896. Pand. Rev. Entom. XV, 208, 1 {Calliphora), 

 — 1924. Stein, Arch. f. Naturgesch. 90, 6, 266, 5. — Musca cognata Meig. 1830. 

 1. c. VI, 374. — 1862. Schin. F. A. I, 577 (Onesia). — 1907. Kat. palåarkt. 

 Dipt. III, 550. — 1911. Kram. Abhandl. Nat. Gesell. Gorlitz, 27, 44, Tab. III, 

 Fig. 14. 



Male. Frons above narrow but orbits not touching; it is slightly 

 protruding, the cheeks somewhat narrow. Orbits and cheeks silvery, 

 shifting to dark; jowls black. Frontal stripe black. Orbits and cheeks 

 witli fine hairs, on the latter only on upper half; 

 jowls black-haired. Occiput bluish, greyish pruinose, 

 all black-haired. Antennæ black, third joint about 

 twice as long as second; arista not densely but long- 

 plumose in about basal two thirds. Palpi black. 

 Thorax blue, somewhat shining, slightly bluish grey 

 pruinose, with three broad shghtly marked stripes; 

 it is black-haired ; three postsutural intraalar bristles 

 but no præsutural. Abdomen blue, third and fourth 

 segment rather distinctly white pruinose with a dark 

 middle line. Abdomen black-haired; third and fourth 

 segment with marginal bristles and most part of 

 fifth with bristles. Genitalia small; upper forceps 

 elongated triangular seen from behind, cleft to 

 middle into two close-lying straight branches, only 

 bent ventrally just at apex; arms of lower forceps 

 broad and oval. Legs black; claw^s and pulvilli only a little elongated. 

 Wings a little brownish tinged; apical cross-vein nearly straight. 

 Squamulæ yellowish, not hairy. Halteres yellowish to brownish yellow. 



Female. Similar; frons about as broad as the eye. Abdomen 

 often less white pruinose than in male. 



Length 5 to fully 7 mm. 



O. caerulea is not rare in Denmark; Ordrup Mose, Charlottenlund, 

 Ermelund, Dyrehaven; on Lolland at Nysted and in Jutland at 

 Sønderborg, Sottrup and Kliplev; the dates are ^V4 — ^Vio- 



Geographical distribution: — Europe; towards the north to 

 middle Sweden. 



Fig. 35. 



O. caerulea, 



forceps in profile. 



