A NOTE ON THE HIBERNATION OF FLIES 8i 



A NOTE ON THE HIBERNATION OF FLIES. 



By J. H. ASHWORTH, D.Sc. 



The notice in the Editorial of the March issue of TJie 

 Scottish Naturalist, on the presence of swarms of flies in 

 houses, suggests that a record of recent observations I have 

 made on the occurrence of flies in a large detached house 

 near the south-eastern boundary of the city of Edinburgh 

 may be of interest. 



I was asked to examine the flies in this house, and did so 

 on 22nd February 1916. A bedroom on the second floor, 

 with a large ba)--window facing south, was first inspected. 

 On the glass of this window, but more especially on the 

 upper sides of the wooden cross-pieces between the panes, 

 also on a ledge just under the window, on the wooden floor 

 below, and on the neighbouring walls, were numerous small 

 flies. Those on the window or in direct sunlight (though the 

 day was cold, the sun was shining brightly during the time 

 of my visit — 1.30 to 2.30 P.M.) were crawling slowly, and only 

 took a short flight on being disturbed ; elsewhere the flies 

 were lethargic, and either remained at rest or were creeping 

 very slowly. Among the small flies were ten larger flies, 

 mostly at rest, but two or three were crawling slowly over 

 the floor. There were very few flies on the ceiling, but many 

 were found resting behind pictures on the south wall of the 

 room. All the large flies and a considerable number of the 

 small ones were collected for detailed examination. A 

 smaller bedroom and dressing-room on the second floor were 

 inspected, and there also the small flies were found about the 

 two windows (which look south and west respectively), though 

 not in the same abundance as in the former room. A bed- 

 room on the first floor and the morning room on the ground 

 floor (each with windows to the south and east), in both of 

 which the small flies were plentiful last autumn, were 

 examined, but yielded no specimens. 



From the large room first mentioned 244 flies were 

 obtained, which have been identified as follows : — 

 ' 52 L 



