Bombyliidae. 127 



bred autumnalis and nitidulus from the same Stauronotus. The larva 

 hibernates as full grown and it pupates and develops to imago in 

 the following summer. 



The species of Systoechus occur in the same way and at the 

 same piaces as the Bombylii. 



Of the genus 19 species are known from the palæarctic region; 

 one has hitherto been found in Denmark. 



1. S. sulphureus Mikan. 



1796. Mikan, Mon. Bomb. Bohem. 52,11, Tab. III, Fig. 1 1 (BomhjUus). 

 - 1855. Loew, Neue Beitr. 111,39,69. - 1862. Schin. F. A. I, 64. - 1820. 

 B. fulvus Meig. Syst. Beschr. II, 205, 25. — 1842. B. minimus Zett. Dipt. 

 Scand. I, 193, 7. 



Male. Ground colour blackish or brownish black. Frons and 

 face with depressed, yellow hairs and with long hairs which are yel- 

 low and blackish intermingled, mainly blackish outwards and yellow 

 inwards towards the mouth aperture. Occiput with depressed, yellow 

 hairs which are nearly hidden by dense, erect, yellow hairs; down- 

 wards, behind the mouth aperture, the hairs are white. Antennæ 

 black, the first joint with black hairs. Thorax densely clothed with 

 erect, bright yellow to pale yellow hairs. Sterna and pleura likewise 

 with long, yellow hairs; metapleura with a vertical tuft of specially 

 long hairs ; postalar and scutellar marginal bristles yellow. Abdomen 

 clothed with long, erect hairs of the same colour as on thorax; the 

 hairs are arranged on the segments in such a way, that they to 

 some degree form transverse rows; there are long, more or less 

 distinctly visible bristles at the hind margin of the segments; these 

 bristles may be blackish or brownish, but they are most often yellow, 

 though darker than the hairs. Venter with long, yellow hairs. Legs 

 blackish or sometimes dark brownish, the outermost base of the 

 femora and the basal part of the tibiæ often lighter to yellowish; the 

 bristles chiefly black, more or less yellow on the hind femora; the 

 femora somewhat yellowish haired below towards the base, the de- 



Fig. 42. Wing of S. sulphureus. 



pressed hairs yellowish. The number of bristles on the ventral side 

 of the hind femora 3 to 5 and on the antero-ventral side of the hind 

 tibiæ 3 to 4. Wings somewhat greyish, slightly brownish towards 



