12G 
PSYCHE 
[October 
was almost complete, the last male flew away. The departing males flew upward 
and none of them alighteil on the stook. 
On the fourth evening the field was visited nearly an hour earlier than before. 
The sun was still shining and there were no moscpiitoes present. Later, when the 
sun had disappeared behind the trees, the swarms were again present just as on the 
previous evenings. On this evening, however, there was quite a breeze blowing and 
the mosquitoes could not maintain their jrosition over the projecting objects and 
swarmed altogether on the leeward side of them. Otherwise their behavior was 
much the same, only that the freshening wind occasionally threw the swarms into 
confusion and greater activity. Rain and cold weather followed the ne.xt day and 
put an end to further observations and [)resumably to the swarming. 
There are many records of swarms of Culicidae and related forms, although in 
many cases there is no exact indication of the identity of the insects in question. 1 
am convinced that all such records, in so far as they refer to swarms of the nature 
described above, apply to Nemocera and probably in every case either to Culicidae 
or Chironomidae. I believe that these swarms of dancing males, congregated for 
sexual intercourse, are |ieculiar to the Nemocera. INIany of the records from un- 
traineil observers, called forth by the appearance of these Diptera in extraordinary 
numbers, though incomplete, are nevertheless of interest. In nearly all of them the 
fact that the swarming leads to sexual union has been entirely overlooked. 
Moufet, in 1034, alrearly s]reaks of these swarms and notes how they gather at 
the gables of houses and over the heads of people passing over bridges. It should 
be noted that in his chapter “ De Culicidum” the Culiciilae and Chironomidae are 
not distinguished, as indeed has been the case with many a writer since. 
The oldest record of the copulation of Culex ap]iears to be that of the Spaniard 
Diego Reviglias, communicated to the Lcopold-Carolinian Academy in a letter dated 
4 March, 1728, but not published until 1737. Reviglias observed under the micro- 
scope, and described at considerable length, the sexual union anil the copulatory 
apparatus of the mosquito. He treats his discovery as a very important one, which 
indeed it was in those days of lingering belief in spontaneous generation. However 
he does not mention swarming and there is reason to believe that he had before him 
a s|)ecies which does not swarm — a matter which 1 shall take up again farther on. 
Later the French commander Godeheu de Riville also claimed as the first his obser- 
vation of the copulation of mosquitoes, made on board his ship. The account is quite 
detailed and it is evident that in this case likewise copulation took place without 
swarming. I shall treat of this article more at length in another place. 
Perhaps the earliest definite record of mosquitoes swarming is that by Swinton, 
