394 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1952 



small settlements and isolated farmhouses. The amount of de- 

 forestation necessary to protect one farmhouse would be the equiv- 

 alent of what would protect scores of houses in a city area. The cost 

 would increase astronomically. There is also the strong probability 

 that further deforestration would have an adverse affect on the water 

 supply. 



In 1945 Pinotti imported a small amount of DDT and began 

 experiments in mosquito control with it. By 1947 he was able to 

 undertake a program for all Brazil, and by 1949 3 million houses 

 a year were being treated. Thus as the cities in Santa Catarina 

 came under control and the campaign shifted to the country districts, 

 a technique was ready to apply to the new problem. 



By itself DDT was not a complete solution since its use in the 

 forest did not prove practical (Ferreira and Kachou, 1949). On the 

 other hand, detailed investigation showed that the mosquito carriers 

 in Santa Catarina were highly domesticated and preferred to dine 

 indoors and at night (Kachou and Lima, 1950). Further research 

 showed that they had a strong preference for resting on the walls at 

 certain levels. They even tended to distinguish between light and 

 dark bands. These peculiarities plus the regional climate were a great 

 help to the DDT campaign. The spray had to be applied only to 

 the upper part of the walls indoors and only once a year, because its 

 6 months' duration covered the rainy season and the mosquitoes were 

 not a problem in the dry season. 



The rural campaign was actually a double campaign because aralen 

 was used against the malaria in its human hosts at the same time 

 that DDT was used against the mosquitoes. The Brazilian Govern- 

 ment bought a large supply of aralen, a drug that has largely suc- 

 ceeded the atabrine that was used against malaria in World War II. 

 Clinics were established in all the municipios involved in bromeliad 

 malaria and aralen administered to all persons who showed symptoms. 



Probably it will never be possible to evaluate the effects of DDT 

 and aralen separately, but the combination was eminently successful. 

 Either the malaria organism lacked mosquitoes to carry it or the 

 mosquitoes lacked malaria to carry. In either event the cycle was 

 broken and the rural areas came under control like the cities. 



One other type of control should be noted, that of herbicide sprays. 

 So far, this method, which provided complete control in Trinidad, 

 has been impractical except in the low coastal forest around cities 

 like Sao Francisco (Veloso, Neto, and Chamarelli, in preparation). 

 Even here a new technique was necessary because there were not 

 enough roads to carry wheeled pumps within striking distance of 

 all the forest area. Instead the Servigo crews cut trails and widened 



