THE ROLE OF ANOPHELINES IN THE 
EPIDEMIOLOGY OF MALARIA 
By ROBERT MATHESON 
DEPARTMENT OP ENTOMOLOGY, NEW YORK STATE COLLEGE OP AGRICULTURE AT 
CORNELL UNIVERSITY, ITHACA, N. Y. 
In 1897 and 1898 Sir Ronald Ross dis¬ 
covered, for the first time, that mosquitoes 
are the transmitters and definitive hosts of 
the malarial organisms of birds and man. 
These results were confirmed by Grassi, 
Bignami and Bastianelli in a series of 
papers in 1898 and 1899. Since that time 
it seems well established that the etiological 
agents ( Plasmodium vivax, P. malariae, P. 
falciparum and also probably P. ovale) of 
malaria of man are transmitted only by 
mosquitoes belonging to the genus Anoph¬ 
eles (in the broad sense). Since 1900 in¬ 
numerable papers have been published on 
human malaria and on their transmitters, 
the anopheline mosquitoes. Summarizing 
the results of all this intensive research, it 
may be stated that it seems established that 
certain species of Anopheles are effective 
and dangerous transmitters of human ma¬ 
laria while others may be considered of 
minor or insignificant importance. Fur¬ 
thermore certain so-called “good” or 
“dangerous” anopheline transmitters are 
known from all the endemic malarial re¬ 
gions of the world. Again, it appears estab¬ 
lished that in some regions the “good” 
transmitters are especially effective in 
transmitting malaria, and the introduction 
of such species into other endemic malarial 
centers may, and frequently does, bring 
about epidemic conditions (as, for exam¬ 
ple, the introduction of A. gambiae from 
Africa to Brazil, and A. albimanus into 
Barbados, Jamaica, and St. Croix). It is 
also apparently well established that cer¬ 
tain species of Anopheles may serve as 
“dangerous” transmitters in one region of 
the world and in another region be unim¬ 
portant or of minor importance in the 
transmission of malaria ( e.gA. pseudo- 
punctipennis is a “dangerous” species in 
Argentina, Mexico, etc., while in the United 
States it is of minor or of no importance; 
A. subpictus (rossi ) and A. hyrcanus are 
“dangerous” in the East Indies, etc., but 
not of importance in India; etc.). Again 
it is reported that in some regions (Dutch 
Guiana) the human population has become 
so attuned or adapted to the malarial 
organisms that the clinical symptoms of the 
disease have almost vanished and the people 
carry on quite effectively despite the para¬ 
sites within them (the “efficient parasite” 
of Swellengrebel 1940). 
Studies of the biology and taxonomy of 
anopheline mosquitoes have been carried on 
intensively in many parts of the world, 
particularly in Europe. In 1900 scarcely 
anything was known about the biology of 
mosquitoes and for many years thereafter 
it was generally considered that the biology 
of all species of mosquitoes was quite simi¬ 
lar. In recent years (1916- . . . ) this con¬ 
clusion has been rudely shattered and we 
feel certain that the biology of each species 
is a very complicated and, in most cases, 
unsolved problem. Similarly with taxon¬ 
omy. In 1900 very few species of anoph- 
elines were known, while today over 170 
species are recorded from the world, and 
as we learn more about them the species 
becomes ever more complex (as, for exam¬ 
ple, the A. maculipennis complex in Eu¬ 
rope, Asia and North America). 
This brief paper is to deal with the role 
of anophelines of North America in the 
transmission of malaria. What are the 
species with which we have to concern our¬ 
selves ? At present this is a somewhat diffi¬ 
cult problem for we are not certain just 
what our species are and certainly we are 
far from knowing their biologies, distribu¬ 
tion, habits, habitats, or their preference 
