528 Syrphidae. 



the first posterior cell; medial cross-vein not oblique, placed on the 

 niiddle of the discai cell; upper marginal cross-vein undulated; the 

 basal part of the radial vein with fine bristles, almost only to detect 

 under the microscope. No stigmatical cross-vein. Squamulæ not large, 

 thoracai squamula w^ith long, branched hairs, alar squamula with some- 

 what shorter, only slightly flattened hairs. Plumula quite short with 

 rather short, simple hairs. 



The developm ental stages of S. pipiens are mentioned by De Geer 

 (Mém. Ins. VI, 1776, 121), who found the larvæ in horse-dung; they 

 pupated in the beginning of May and developed at the middle of the 

 same month. Scholtz (Ent. Zeitschr. Breslau, 1 — 3, 10) found the larvæ 

 in cow-dung. Beling (Arch. f. Naturg. 48, 1, 1882, 233) describes the 

 larva and pupa. The larvæ were found numerously together in dense 

 clumps under rotten straw and other vegetable matter at the end of 

 March; they developed on ^^k and the foUowing days. Terry (Proc. 

 Hawaiian Ent. Soc. II, 1910, 96) records the life history of S. oceanica 

 Macq., but I have not seen this paper. I have myself examined pupæ 

 found in a fen in heaps of vegetable matter in August. According to 

 Beling the larva is 10 mm long, about cylindrical, a little attenuated 

 towards both ends; it is dirty yellowish, the dermis is tough, short- 

 spinulose; the segments with about four corrugations each; on the 

 ventral side are seven pairs of small prolegs with spines; the pro- 

 thoracal segment has at the front margin numerous short, brown, 

 recurved spines in transverse rows; above the mouth opening are as 

 usual the two-jointed antenna-like organs ; at the posterior end of the 

 body are on each side three filaments, the posterior of which are the 

 largest; at the end itself is a brown, somewhat flattened posterior 

 spiracular process, it has a longitudinal dividing line above and below 

 and bears the spiracles on the flat end. The pupa is arched, rounded 

 in front, slightly attenuated behind; near the anterior end are two 

 short, cylindrical, yellow anterior spiracular tubes, they are a little 

 distant, directed upwards and diverging, and they have the somewhat 

 thickened apical half beset with small tubercles, partly arranged in 

 rings; at the posterior end is the larval posterior spiracular process, 

 directed a little upwards. The length is about 6 mm. 



The species of Syritta are characteristic flies by their strongly 

 thickened hind femora; our Danish species, which is very widely 

 distributed and common, is an excellent hoverer and is seen every- 

 where hovering around flowers and bushes; Zetterstedt tells (II, 881) 

 that the male hangs in the air before the female sitting on a leaf, and 

 soon after the copulation takes place. 



Of the genus 6 species are recorded from the palæarctic region, 



