52 
PROPHYLAXIS OF MAI.ARIA. 
tioned Anopheles crucians , Myzomyia ludlowii , Anopheles quadri- 
macutatus , Cellia ( Anopheles ) alhimanus , Cellia ( Anopheles) ary y- 
ritarsis , and Anopheles tarsimaculata. 
From this very brief discussion of the breeding places of the 
Anophelince it is evident that in malaria prophylaxis the practical 
point to remember is that no collection of water, however minute, 
should be considered as of no importance as a breeding place for these 
insects. As Smith has well said, the Anopheles breed “ everywhere ,” 
and therefore every collection of water should be carefully examined 
before it is considered free from the larvae of these insects. 
Certain colors in relation to the Anophelince .—It is a well known 
fact to anyone having experience with mosquitoes. that they prefer 
dark to light colors and that a person dressed in black is much more 
apt to be bitten repeatedly than a person dressed in white. The re¬ 
searches of Nuttall and Shipley 24 have shown that A. maculipennis 
is very partial to certain colors, and this is probably true of other 
species of anophelines. They found that dark blue was the most 
attractive color to them and that pale green, light blue, orange, and 
yellow actually appeared to repel them. They call attention to the 
khaki uniform as especially suitable because of its lack of attraction 
for the insects. 
Longevity and- hibernation .—Our knowledge regarding the longev¬ 
ity of the Anophelince is still incomplete, but we know that the life 
of the male is only a few days and that the females of different 
species vary greatly in length of life, some living for weeks only, 
while those that hibernate may live for many months. 
In temperate climates the winter is passed by most anophelines in 
the adult stage of development, the females alone hibernating. 
Although this is so, the anophelines may pass through the winter 
in the ova or as larvae. The females that hibernate are fertilized, 
and only lay their eggs in the spring, although if a warm spell 
occurs during the winter some of them will emerge from their bid¬ 
ing places and bite, and may thus cause outbreaks of malaria even 
in the middle of winter. 
In the Tropics the adult anophelines hibernate during the hot dry 
season and lay their eggs at the beginning of the rainy season. As 
long as the weather is dry very few anophelines will breed in the 
Tropics, but the beginning of the rainy season is always marked by 
an immense increase in the number of these mosquitoes, and breeding 
places are easily found. 
During hibernation the adult insects may be found in cellars, out¬ 
houses, stables, under the roofs of unceiled habitations, in dark 
closets, in hollow trees, or under shelving. In these situations they 
may be found in hundreds, or even thousands, and if disturbed 
appear sluggish and only fly for short distances. 
