68 
Psyche 
[September 
SWARMING CHIRONOMIDiE 
By J. P. Bill 
One evening during the spring grass fire season, the 
writer happened to notice some suspicious streamers of 
what appeared to be smoke. They proved to be above a 
large elm tree several hundred feet away, where they caught 
the quartering light of the setting sun. The children soon 
found others. In fact, all around us, against the sky, could 
be seen these columns, slightly swaying in the breeze, and 
all apparently tenuously anchored to tree tops. The near- 
est one, over a young elm sapling in our own yard, was 
close enough to determine the smoke to be columns of my- 
riads of insects. 
An aerial net lashed to an apple picker was barely long 
enough to sweep through this column, which proved to con- 
sist of Chironomids. These were identified later by Mr. C. 
W. Johnson of the Boston Society of Natural History (with 
whom specimens were left, and to whom my thanks are 
due) as being Chironomus modestus Say, Cricotopus tri- 
fas ciatus Panzer, and Chironomus nigricans Johannsen, the 
latter predominating in the collections, of which three were 
made on different days. 
For the next few days, in travelling about the region of 
Wayland, these columns were seen at sunset, and were ob- 
served by others. One sunset was accompanied by a fitful 
westerly wind. While the columns were temporarily dis- 
persed, the insects quickly flew back to their position, which 
they maintained even in the height of the gusts. 
Toward the end of approximately a week, during which 
these columns were seen in the evening, large numbers of 
them started to appear in the writer’s study, where a 
valved screen frame, backed by a light, is in nightly use to 
attract insects. Their disappearance at light was coinci- 
dent with that of the columns. 
Whether this phenomenon is one of a modified swarming 
instinct or nuptial flight is not known to the writer, but its 
persistence and peculiarity is thought worthy of note. 
These observations were made during the first week in 
May, 1931. 
