Chalarus. 61 



segment miich longer than fourth, the discai vein abbreviated just 

 after the medial cross-vein, only continued as a slight fold and thus 

 no discai cell present; anal vein very weak; axillary vein present in 

 the male as a weak fold, absent in the female. 



The developmental stages have not been described, but the 

 species is parasitic on Ho?noptera; it has been bred from Cicadellines 

 by Tetens (Ent. Nachricht. XV, 1891, 1) and from Tijphlocyba hippo- 

 castani and Douglasi by Giard (Compt. rend. Acad. Se. Paris, CIX, 

 708); it lives here in the same way as the larva of Pipiinculus^ and 

 Giard mentions the curious alterations and reductions of the exterior 

 genitalia of the Homopteron caused by the presence of the parasitic 

 larva. I have myself bred the species from pupæ found in hollow trees 

 and in flood refuse in spring. The pupa is reddish brown, quite oval 

 and rounded at the ends, the surface apparently smooth, at the post- 

 erior end is a small black, roundish triangular spiracular plate with 

 the spiracles lying at each side, the anterior spiracular tubes are 

 yellow, short and curved forwards, The curious way in which the 

 puparium is opened by the emergence of the imago is mentioned 

 under the family. As before said the pupa was found in spring and 

 had no doubt hibernated; Giard declares the species to have two 

 broods in the year, with us it has probably only one. 



The species of Chalarus occurs in woods, especially in somewhat 

 humid piaces, and it hovers here on bushes and in low herbage and 

 is sometimes present in great numbers; it is, I think, the most ex- 

 quisite hoverer of all Diptera; when caught in a deep net it is able 

 to raise vertically quite from the bottom up to the edge and coming 

 here it gives a jerk to the side and is away. 



Of the genus only two species exist in all (holosericeus taken as 

 a synonym to spurius), spurius Fall. and basalis Low (if the latter 

 is really distinct); one, the widely distributed spurius, is found in 

 Denmark. 



1. Ch. spurius Fall. 



1816. Fall. Dipt. Suec. Syrph. 16, 3 (Cephalops). - 1824. Meig. Syst. 

 Beschr. IV, 24, 11, Tab. XXXIII, Fig. 24 {Pipmiculus). - 1838. Zett. Ins. 

 Lapp. 580, 8 et 1844. Dipt. Scand. III, 968, 23 et 1852. XI, 4312, 23 et 1859. 

 XIII, 6060, 23 (Pipunculus). — 1862. Schin. F. A. I, 245. - 1869. Thoms. 

 Opusc. Entom. II, 123, 25 {Pipunculus). — 1894. Strobl, Mittheil. Nat. Ver. 

 Steierm. XXX, 1. — 1897. Beck. Berl. Entom. Zeitschr. XLII, 96, 56. - 1901. 

 Verr. Brit. Flies VIII, 68, 1, fig. 88. — 1910. Kertész, Cat. Dipt. VII, 385. 

 — Pipunculus holosericeus Meig. 1824. 1. c. IV, 24, 12. — Ch. holosericeus 1862. 



