114 MOSQUITOES OF NORTH AMERICA 
Smith, in discussing the question of the food of adult mosquitoes, states that 
he has examined the stomachs of a number of specimens, and has found some of 
them filled with a colorless liquid like plant nectar. On the other hand, with 
Aédes sollicitans, a salt marsh species, he has found the stomach filled by a mass 
which he could not distinguish from thin marsh mud. 
Some very interesting observations have been made upon biting of corpses by 
mosquitoes. In our section on yellow fever we have given an account of experi- 
ments made with captive Aédes calopus at Vera Cruz. In these it was shown 
that one female feeding upon a corpse twelve hours after death apparently ob- 
tained blood, but this was only one of a number; three of a number in another 
case, one-half hour after the death of the patient, succeeded in feeding with 
blood. Christy, in making a post-mortem examination in Nigeria, found a num- 
ber of a large brown Anopheles feeding upon the body of a non-commissioned 
officer who had died three and a half hours previously. 
The laboratory studies consequent upon the discovery of the relations between 
mosquitoes and certain diseases have brought about necessary experimentation 
as to the kinds of food upon which to prolong the life of blood-sucking mos- 
quitoes used for experimental purposes, and it has been found that they will live 
almost for indefinite periods upon a vegetable diet, bananas, dates, raisin-grapes, 
and other fruit used for this purpose, and it has been found that frequent meals 
of water are necessitated in order to prolong life. One of us (Dyar) has reared 
two successive generations of Aédes atropalpus in captivity by feeding the adults 
upon sugar and water. 
MOSQUITO SONGS AND THEIR POWER OF HEARING. 
Probably owing to an association of ideas, the curious sound made by mos- 
quitoes as they approach one’s ear is to most people extremely irritating. This 
faint sound will waken many from the soundest sleep. It is not loud, and in 
quality may perhaps best be compared to the distant note of a bagpipe. 
As with flies and other dipterous insects the sounds emitted by mosquitoes 
are not a true voice. It has been supposed that the sounds are produced in two 
ways, by the vibration of the wings and by air forced through the thoracic 
stigmata. Landois, in his classical paper on the sound-producing organs of 
insects, apparently proved the latter to be the case, but more recent investiga- 
tions show that he was at fault in his conclusion that the stigmata emit sound. 
Landois thought that mosquitoes produce sounds in two ways. The normal 
tone, which can not be modified in any way by the insect, is produced by the 
wing stroke. The common Culex pipiens during flight produces the sound 
= (d’). If one removes the wings, head, and all the legs of such a 
mosquito she emits a sound which is much higher than that produced in flight. 
This sound Landois thought to be produced by the stigmata of the thorax and 
said it might be called the voice of the mosquito. He found within the spiracle, 
a membrane, stretched like a double curtain, which he supposed produced the 
sound when the air was forced through it. He considered the posterior thoracic 
