NATURALISTIC METHODS OF MALARIA CONTROL 
By PAUL F. RUSSELL 
INTERNATIONAL HEALTH DIVISION, ROCKEFELLER FOUNDATION, COONOOR, NILGIRIS, INDIA 
A naturalistic method of mosquito con¬ 
trol may be defined as one that deliberately 
extends or intensifies natural control. Biol¬ 
ogists speak of contending natural forces 
of potential creation and potential destruc¬ 
tion (Chapman 1925). A pool that offers 
suitable conditions for larvae is a natural 
creative force; a growth of plant that 
eliminates larvae from the pool is a natural 
destructive force. Most mosquito control 
measures aim either to destroy mosquitoes 
or to eliminate forces that are potentially 
suitable for their creation. But natural¬ 
istic control differs from these measures in 
that it aims primarily to utilize specific 
natural forces inimical to mosquito density 
or dangerous activity. To poison larvae 
with Paris green is to cause death in an 
unnatural way; to put water underground 
in subsoil pipes is to destroy a natural mos¬ 
quito-creating force. But to shade a breed¬ 
ing place is to intensify a specific natural 
limiting force. Sometimes it is cheaper to 
go with such natural forces than against 
them, hence the special significance of 
naturalistic methods. 
Since the paper by Williamson (1935) 
and a League of Nations’ bulletin (Hackett 
et al. 1938) naturalistic control has had 
increasing attention from malariologists, 
but there has not been agreement as to 
what measures should be included under 
this classification group. Probably too 
many measures have been put in this cate¬ 
gory, for there are secondary naturalistic 
aspects in many control procedures, such as 
sluicing and draining. A classification 
should be based on primary character, 
which in sluicing is management of water 
and in drainage is elimination of water, 
each largely by mechanical effort. The 
following discussion, with one or two excep¬ 
tions, will be limited to measures that ap¬ 
pear to be definable as primarily natural¬ 
istic. 
It must be emphasized that (a) knowl¬ 
edge of anopheline biology is inadequate 
to permit fullest use of naturalistic mea¬ 
sures; (b) all methods must be chosen to fit 
specific requirements; (c) all have inher¬ 
ent defects and dangers; and (d) there is 
no good reason (except experimental) why 
the application of any type of malaria 
control need be kept unmixed with the use 
of others. 
Naturalistic Measures Against Adult 
Mosquitoes 
Erecting plant barriers, either to repel 
the insects or to block their flight, adminis¬ 
tering drugs to modify perspiration so that 
mosquitoes would be repelled, treating bed¬ 
rooms, houses, or compounds, to render 
them unattractive to mosquitoes, using 
natural predators (including bats), in¬ 
tensifying winter killing, or attempting to 
deviate vector species from man to animals 
for their food—none of these measures has 
yet been proved effective. All but the 
last-named can be dismissed with the hope 
that in time adequate experiments will 
make it possible to evaluate them. 
Deviation of vector species from man 
to animals, zooprophylaxis, has had con¬ 
siderable attention, for undoubtedly the 
presence or absence of malaria in some 
areas depends somewhat on whether or 
not, and to what degree, local anoph- 
elines are naturally anthropophilie or zoo- 
philic. “Anophelism without malaria,” 
while sometimes mainly due to inadequate 
density of vector species, is probably fre¬ 
quently dependent on the fact that local 
anophelines prefer animal blood to that of 
man. Among the 180 or more species in 
the genus Anopheles, only about 24 have 
been proved to attack man as their pre¬ 
ferred hosts and only about 15 have been 
incriminated as serious vectors. But the 
situation is complicated not only by 
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