HOUSING WITH REFERENCE TO MALARIA CONTROL 
311 
the work was considered to have value as 
an educational measure. 
The completion of mosquito-proofing on 
a group of 700 rural houses located about 
the Tennessee Valley Authority’s Wheeler 
Reservoir on the Tennessee River in North 
Alabama provides more recent information 
and data on this subject (Watson and 
Maher 1940; Kiker and Breedlove 1941; 
Watson and Rice 1941). 
The marginal areas of the central part 
of the Wheeler Reservoir are characterized 
by extensive shallows where a combination 
of rich alluvial soil, moisture and water- 
tolerant plants has made it very difficult, if 
not impracticable, to provide completely 
effective control of A. quadrimaculatus 
through biological means. In attempting 
to control or limit mosquito production 
from these areas Paris green dust was ap¬ 
plied as a larvicide by use of airplanes. 
Routinely, however, it was found difficult 
to obtain a kill of larvae approaching 90 
per cent with Paris green dust. This failure 
to obtain a complete kill of larvae per¬ 
mitted a significant emergence of A. quad¬ 
rimaculatus, since the size of the breeding 
areas in question is very large. A further 
difficulty was that mosquito production oc¬ 
curred from natural breeding areas border¬ 
ing the reservoir which were in no way af¬ 
fected by the impoundage. It was seen, 
therefore, that regardless of the degree of 
mosquito control obtained on the lake, suf¬ 
ficient A. quadrimaculatus would emerge 
from the natural ponds for serious malaria 
transmission. 
The question of alternative methods of 
control was placed before the Tennessee 
Valley Authority’s Board of Malaria Con¬ 
sultants 1 which recommended that mos¬ 
quito-proofing be tried and studied over a 
period of some 5 years to obtain informa¬ 
tion on effectiveness and costs, from which 
1 Dr. Mark F. Boyd, Rockefeller Foundation; Col. 
George C. Dunham, TJ. 8. Army; Comm. C. S. 
Stephenson, U. S. Navy; Dr. T. H. D. Griffitts, 
Dr. L. L. Williams, Jr., Mr. J. A. LePrinee, TJ. 8. 
Public Health Service; Mr. G. H. Hazlehurst, Ala¬ 
bama State Department of Public Health; Dr. W. 
V. King, H. S. Department of Agriculture; Dr. 
Robert Matheson, Cornell University. 
a decision might be made as to the place of 
mosquito-proofing in malaria control asso¬ 
ciated with impounded waters. The Ala¬ 
bama State Department of Public Health 
agreed to employment of mosquito-proofing 
as a temporary substitute for larvicide in 
certain areas. The Department adminis¬ 
tered the construction work, which was 
financed by the Tennessee Valley Author¬ 
ity from an allotment for malaria control 
on Lake Wheeler. Controls of nonmos¬ 
quito-proofed houses were established. The 
study was begun in 1938 and has been car¬ 
ried out as a cooperative endeavor between 
the State Department of Public Health and 
the Health and Safety Department of the 
Tennessee Valley Authority. 
The initial mosquito-proofing work, com¬ 
pleted in the spring of 1938, embraced 100 
houses in the Harris Station Area. The 
results obtained during the first season of 
transmission were inconclusive, but were 
so encouraging that additional groups 
totaling 243 houses were mosquito-proofed 
during 1939. The second season’s observa¬ 
tions tended to confirm the first and a 
further expansion was made during 1940, 
bringing the total to 702 houses mosquito- 
proofed to date. Data bearing on effec¬ 
tiveness are shown in the following two 
graphs. 
Total Morbidity Rates in Three Test Areas, 
Wheeler Reservoir, 1939 
MAY JUNE JULY AUGUST SEPTEMBER 
1. All bouses mosquito-proofed. 2. Control area; 
no houses mosquito proofed. 3. Mosquito-proofing 
50 per cent complete July 1; 75 per cent July 15; 
100 per cent August 1. Scale on the left is the 
number of cases per 1000 persons. 
