g8 
Parasitic Arthropoda 
Aside from their importance as carriers of disease, mosquitoes are 
notorious as pests of man, and the earlier literature on the group is 
largely devoted to references to their enormous numbers and their 
blood-thirstiness in certain regions. They are to be found in all 
parts of the world, from the equator to the Arctic and Antarctic 
regions. Linnaeus, in the “Flora Lapponica,” according to Howard, 
Dyar and Knab, “dwells at some length upon the great abundance of 
mosquitoes in Lapland and the torments they inflicted upon man and 
beast. He states that he believes that nowhere else on earth are they 
found in such abundance and he compares their numbers to the dust 
of the earth. Even in the open, you cannot draw your breath without 
having your mouth and nostrils filled with them; and ointments of 
tar and cream or of fish grease are scarcely sufficient to protect even 
the case-hardened cuticle of the Laplander from their bite. Even in 
their cabins, the natives cannot take a mouthful of food or lie down 
to sleep unless they are fumigated almost to suffocation.” In some 
parts of the Northwestern and Southwestern United States it is 
necessary to protect horses working in the fields by the use of sheets or 
burlaps, against the ferocious attacks of these insects. It is a sur¬ 
prising fact that even in the dry deserts of the western United States 
they sometimes occur in enormous numbers. 
Until comparatively recent years, but few species of mosquitoes 
were known and most of the statements regarding their life-history 
were based upon the classic work of Reaumur (1738) on the biology 
of the rain barrel mosquito, Culex pipiens. In 1896, Dr. Howard 
refers to twenty-one species in the United States, now over fifty are 
known; Giles, in 1900, gives a total of two hundred and forty-two 
for the world fauna, now over seven hundred species are known. 
We have found eighteen species at Ithaca, N. Y. 
All of the known species of mosquitoes are aquatic in the larval 
stage, but in their life-histories and habits such great differences occur 
that we now know that it is not possible to select any one species as 
typical of the group. For our present purpose we shall first discuss 
the general characteristics and structure of mosquitoes, and shall 
then give the life-history of a common species, following this by a 
brief consideration of some of the more striking departures from what 
have been supposed to be the typical condition. 
The Culicidse are slender, nematocerous I ffptcra with narrow wings, 
antennae plumose in the males, and usually with the proboscis much 
longer than the head, slender, firm and adapted for piercing in the 
