1913 ] 
Burrill: Lake Michigan Swarms of Chironomids 
65 
MIDGE HUMMING 
During the afternoon of May 24, 1910, the midges did not give 
vent to the acute buzz noted 1 in the morning, and previously. 
May it not be that this species, which must have been busy 
mating at least all the afternoon, judging from the number of 
couples seen at 6 p.m., discontinues the humming noise when the 
hours of mating are at their height. In the swarm of June 4, 
1912, no sound was noticeable and that despite the absence of 
mating couples, hence this query appears unfounded in fact. At 
other times as I approached such a swarm in 1910, the noise 
distinctly increased; then when I remained motionless, the sound 
would decrease until inaudible at the distance of a few yards. 
Morley (l.c.) observed at Monk Soham House, Suffolk, England, 
that the humming during the lulls of the gusty wind, rose and fell 
in exact ratio to the proximity of the insects, both sexes of Tanypus 
varius Fabr. and C. dorsalis Meig. flying at 9 p.m., July 12, 1909. 
At 7 :45 p.m., August 7, 1912, males only of the above species were 
flying and made absolutely no audible sound. Further study 
revealed the fact that two other color phases of midges, one being 
brown, occasionally came in these swarms; but certainly these 
few forms were negligible in judging the humming noise of the 
predominant species. At 7 p.m., June 3, 1912, Professor Sanders 
and the writer noted some dozen large midges flying with the 
swarm of tiny midges noted elsewhere. Sound determination was 
not attempted. 
Burmeister, about 1832, is one of the first to note the noise of 
flies made during flight, according to Westwood (1840, An Intro- 
duction to the Modern Classification of Insects , vol. 2, p. 496) the 
latter speaking of the dance flight of gnats in general, although 
it is a little hard to follow his statements as to whether he always 
refers to Chironomus plumosus which he sets out to describe, or 
refers to other species also. Since his day several noteworthy 
papers have appeared, of which the following may be listed: 
Mayer, A. M. 1874 Experiments on the Supposed Auditory Apparatus 
of the Mosquito. Am. Nat., v. 8, pp. 557-592, fig. 92. 
Graber, V. 1882 Die chordotonalen Sinnesorgane und das Gehor der 
Insecten. Archiv. mikr. Anat., bd. 20, pp. 506-640, pis. 30-35, 
figs. 6; bd. 21, pp. 65-145, figs. 4. Good bibl. 
