Report of the State Entomologist. 187 



Localities of its Occurrence. 

 The editors of the American Entomologist have identified the galls 

 from Des Moines, Iowa. The Osten Sacken catalogue of N. A. Dip- 

 tera gives its habitat as " District of Columbia and elsewhere." In 

 former years I have received it from Staatsburg, N. Y., and from New 

 Jersey, where it occurred on the Concord grapevine. It has also been 

 received by me from Orange county, N. Y., on a Muscadine vine ; from 

 Worcester, Mass., on a "Eogers 15" seedling; and from Schenectady, 

 N. Y., as before stated, on a wild grapevine. 



CMoropisca prolifica Osten Sacken, n. sp.. 



And Its Winter Gtatheeings in Dwellings. 



(Ord. Diptera: Fam. OsciNiDiE.) 



The immense numbers in which various insects, which are not recog- 

 nized as social in their nature, are observed to congregate at certain 

 times, and under certain conditions, is a phenomenon full of interest, 

 and one for which no satisfactory explanation has been offered. With- 

 out citing an extended list of such assemblies, a few of those in which 

 species of Ghlorops, belonging to the family of Oscinidce, have been 

 drawn together for hibernation will be mentioned, in connection with 

 two recent instances of the kind brought to my notice. 



A Remarkable Assemblage of Flies at Franklin, N. H. 



In March last, examples of a small fly were received from Mr. W. F. 

 Daniels, of Franklin, N. H., with the statement that they were infest- 

 ing his residence in such number that it was impossible to rid the 

 house of their presence. They had become a great nuisance. Through 

 several letters received in relation to them, the following account has 

 been compiled: 



The fly had been observed as early as the last week in August, in 

 quite an active state about crevices in the wood-work and the windows 

 of the second floor, where it was seeking entrance. 



Later in the season a favorite gathering place for them was found 

 to be in the space between the window sashes and the casings. Here ' 

 they appeared to rest in stupid condition, but if the attempt was made 

 to capture them, they flew briskly away. When the gas was lighted 

 they flitted around the room in great numbers, and alighted on the 

 ceiling and walls. They were not distributed generally over the house, 

 but were almost confined to the north side — the front of the house — 

 and to the second story. None were seen on the third floor, and 

 comparatively few on the first. In a closed room thousands could be 



