390 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1946 
wise incapacitate them. Neither quinine nor atabrine, however, is an 
ideal antimalarial for neither will destroy certain stages of the parasite 
(sporozoites) or prevent mosquito-borne infection. Neither drug com- 
pletely cures tertian malaria although atabrine appears to be excellent 
in preventing the development of the most dreaded type of malaria, the 
so-called malignant tertian. A coordinated effort is being made to find 
better antimalarials than quinine or atabrine. For these experimental 
studies 1 percent of the ducks in the United States are being used. 
Control of malaria depends fundamentally on the prevention of 
bites by infected anopheline mosquitoes. Draining or filling mosquito 
breeding places, destroying the larvae there, screening buildings, and 
spraying insecticides are measures employed at Army base installa- 
tions. A “mosquito bomb” has been developed which employs pressure 
from the inert gas freon to discharge an insecticide far more effectively 
than can be done with a flit-gun. The most outstanding advance in 
insect control during this war has been the discovery of the remarkable’ 
insecticidal properties of DDT, which stands for dichloro-diphenyl- 
trichlorethane. Its use prevented a serious epidemic of typhus in 
Naples just as our troops arrived there and it is proving of great 
importance in the control of malaria. 
The war and modern transportation have made acute the problem 
of transmission of disease by insects. Yellow fever, ike malaria, 1s 
transmitted by mosquitoes. Certain flies transport the trypanosome 
of African sleeping sickness. Bubonic plague is carried from rat to rat 
by the bites of fleas and from rats to man by the same insect. Lice 
transmit typhus and relapsing fever. These few examples indicate 
that insects carry viruses, bacteria, protozoa and spirochetes to man. 
Thus, as Huff (5) has put it, “Long before man became air minded, 
some of the microbes were using insects for transportation.” It is 
not difficult to imagine how, when this limited means of transporta- 
tion is aided by man’s mechanical wings, the transmission of disease 
and the possible development in this country of what we once con- 
sidered exotic diseases may become a very serious problem. “The 
flea which carries bubonic plague and normally hops a distance of 
3 to 5 inches may possibly hop from one continent to another. Ticks, 
which are among man’s worst enemies, have been restricted in their 
range by poor powers of locomotion. Will they discover our wings 
and ‘hitch-hike’ a million times as far?” (5) 
In 1938 Whitfield investigated the insects found inside aircraft. 
He collected 277 species of insects and these included 5 species of 
mosquitoes known to be capable of transmitting yellow fever and 5 
species which can transmit malaria. There was also a specimen of 
tsetse fly which transmits African sleeping sickness, a bed bug, a flea, 
many horse flies, many species of house flies, cockroaches, and black 
