Histochaeta. 397 



87. Histocliaeta Rond. 

 {Istocheta.) 



Species of medium size, blackish, with conspicuous greyish prui- 

 nosity. The genus is nearly related to the preceding. Head broader 

 than thorax, shaped about as in Baumhaueria, but higher. Frons 

 very broad, a little broader in female than in male, less protruding 

 than in Baumhaueria. In both sexes ocellar, inner and outer vertical 

 and two orbital bristles. Behind postocular bristles no black hairs. 

 Frontal bristles not much descending, but, however, reaching to 

 insertion of arista, as second antennal joint is very short, about 

 two upper reclinate; outside to the frontals a row of about four 

 bristles. Cheeks bare. Vibrissæ strong, ascending to near insertion 

 of arista. Eyes practically bare, but, however, with discernible, short, 

 sparse hairs. Proboscis short, not slender. Antennæ inserted high 

 above middle of the eye, second joint very short, third about eight 

 times as long in male, a little shorter in female; second joint with 

 curved bristle on front side; arista with second joint short. Thorax 

 rectangular; four postsutural dorsocentrals and three præ- and three 

 postsutural acrostichals; a præsutural intraalar bristle. Scutellum 

 with three marginal bristles on each side; no apical bristles, but a 

 pair of præapical quite near the margin, and in front of them a pair 

 of discai. Three sternopleural bristles. Pteropleura with a bundle 

 of hairs and a bristle above. Abdomen subcylindrical or elongated 

 conical; excavation on second segment small, not by far reaching 

 hind margin; there are discai and marginal bristles, on second seg- 

 ment a pair of marginal. Genitalia small, upper forceps cleft apically. 

 Legs with anterodorsal bristles on hind tibiæ somewhat unequal, 

 and with some longer bristles in the row; claws and pulvilli small 

 in both sexes; front tarsi in female simple. Wings with first posterior 

 cell narrowly open, ending somewhat before apex of wing; a small 

 costal spine. 



The species marmorata is parasi tic on Heterocera and also on a 

 Chrysomelid; it belongs to Pantel's group 2 (Thompson 1924). 



Two species are known, one occurring in Denmark. 



1. H. marmorata Fabr. 



1805. Fabr. Syst. Antl. 300, 84 (Musca). — 1896. Pand. Kev. Entom. 

 XV, 112, 7 (LatreilUa). — 1207. Kat. palåarkt. Dipt. III, 359. — 1921. Baer, 

 Zeitschr. f. angew. Ent. VII, 361. — 1924. Stein, Arch. f. Naturgesch. 90, 6, 



