66 Journal New York Entomological Society. [Vol. xxi, 



SYRPHID^ IN THE HYDROPHYTIC AREA. 



By Raymond C. Osburn, 

 New York, N. Y. 



Very few of the Syrphidse actually live in the water at any time 

 of the life cycle, though certain of the Eristalinse, which have " rat- 

 tailed " larvae, inhabit muddy pools and saturated filth during the 

 larval stage. It is true that many species may be found about flowers 

 in swamps, but often these are merely strong fliers that have found 

 their way there for the sake of visiting the flowers and have no 

 relation to the hydrophytic environment otherwise. They must be 

 classed as stragglers. A few species have been reared from larvae 

 taken in the flowing sap of trees and the larvae of Chilosia alaskensis 

 Hunter and C. hoodiana Bigot live in the resinous sap of coniferous 

 trees just beneath the bark where they produce the timber blemish 

 known as " black check." 



The adults of certain species habitually frequent the marsh grasses 

 at the edge of streams and in swamps, and may be considered a part 

 of the regular fauna of such situations. Such are Platychirus quad- 

 ratiis Say, P. hypcrboreus Staeg., and P. chcctopodus Williston. 

 These species are not very strong fliers, as Syrphids go, and are sel- 

 dom found far from swampy regions. Their breeding habits and 

 those of the larvae are unknown. All of them have been taken at 

 Ft. Lee, N. J., and at Van Cortlandt Park, New York. 



Of the species which breed in wet filth may be mentioned Eristalis 

 tcnax Linne, E. hastardi Macquart and E. ccneus Fabricius, all of 

 which belong to the fauna of the hydrophytic region, even though the 

 adults may wander long distances from the water in visiting flowers. 

 These species may frequently be taken around New York City, about 

 their breeding places. The writer has observed tenerals of E. mei- 

 genii emerging from a pile of saturated horse manure. 



Helophilus Icrtus Loew and H. hamatus Loew are usually found 

 only about marsh flowers or close to marshy places. Although their 

 larval habits are unknown the constantly limited distribution of the 

 adults about swamps and pools seems to indicate that they belong to 

 the hydrophytic area. Tropidia quadrata Say is also found pretty 

 constantly about marsh grasses and at the edges of wet areas. 



