CHAPTER VI
MOSQUITOES
osquitoes are no more abundant now than they have been in the past, but when Linnæus in 1758 made his list of all the animals known to exist at that time he catalogued only six species of mosquitoes. Only a few years ago, 1901, Dr. Theobald of the British Museum published a book on the mosquitoes of the world in which he listed three hundred and forty-three kinds. Soon other volumes appeared, adding more species, and systematists everywhere have been describing new ones until now the total number of described species is probably over five hundred, more than sixty of which occur in the United States.
This shows only one phase of the great interest that has been taken in the mosquitoes since the discovery of their importance as carriers of disease. Not only have they been studied from a systematic standpoint but an endless amount of work has been done and is being done in studying their development, habits, and structure until now, if one could gather together all that has been written about mosquitoes in the last ten or twelve years he would have a considerable library.
 Fig. 50 |  Fig. 51 |
 Fig. 52 | |
Fig. 50—Pupa of house-fly with the end broken to allowthe fly to issue. Fig. 51—Head of stable-fly showing sharp piercing beak. Fig. 52—Mass of mosquito eggs (Theobaldia incidens). | |
Fig. 53—Mosquito eggs and larvæ (Theobaldia incidens); two larvæ feeding on bottom, others at surface to breathe.