1906] 
K\AB—Sn\iRMI\G OF CVLEX PIPIEXS 
12.5 
In the corn-field the swarms were found, as on the evening before, over every prominent 
object and as the writer entered the field a swarm immediately began to form over 
his head. This time, however, the jiosition of the swarms in relation to the objects 
was the opposite of the evening before — the moscpiitoes were now all facing south- 
ward and they kej)t on the north side of the objects. The trees on the south side 
of the field, some of them 25 or 30 feet high, had immense clouds on their north sides. 
As on the evening before, there was no ]ierceptible breeze but the drift of smoke 
showed that there was a current of air from the .south. Station was taken near the 
row of trees bordering the field and some swarms dancing before projecting limbs 
ke|)t under observation. Repeatedly females were seen to issue from the foliage, 
dash into the swarm, and emerge united with a male. IVhen in copula the male 
and female face in opposite directions, their bodies in a horizontal plane; the female 
dragging the male after her.* The pair (or rather the female) would fly upward for 
a while and then slowly drift towards the ground. Once a pair in copula was seen 
to issue from one swarm and plunge into another swarm elo.se by. The pair made 
great haste to e.xtricate itself while the swarm was immediately thrown into frantic 
e.xcitement and the mosquitoes danced u]i and down at a furious pace for some 
time, until at last the ordinary measure of speed was regained. With the growing 
darkness the excitement in the swarms increased and the movements became more 
rapid. Few successful unions now took place. Females entering the swarm would 
be pounced upon by two or three males, and together, tumbling over each other, 
they would fall to the ground and there separate. Towards the last no more females 
appeared and with the increasing darkness the swarms rapidly tliminished, the males 
flying off into the air. 
At five o’clock on the following evening the swarms were found as before, dancing 
over every object projecting above the general level. Single mosquitoes were seen 
flying rapidly and straight. These looked larger than the dancing males and when 
captured proved to be females. The air was again very still with a current from the 
south and, as before, the dancing males faced towards it and ke])t on the opposite 
side of the objects. The west side of the field was bounded by tall trees and high up 
on these, at lea.st fifty feet from the ground, before projecting branches, clouds of 
mosquitoes could be distinguished while lower down on these trees there were none. 
Station was taken at a corn-stook to determine how long the dance would continue. 
As the darkness grew the numbers began to diminish, and at 5.50, when the darkness 
*Goeldi (Os mosquitos no Pard, 1905, p. 74. pi. I. fig. 3a) describes ami figures the copulation of 
Siegomyia calopus. In that species the male clings to the under side of the female. 
