362 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1947 



form. In this manner I collected a wide variety of mosquitoes and 

 other insects. (On one occasion I caught a bat.) 



With the aid of D. C. Geijskes, an entomologist from the Surinam 

 Agricultural Experiment Station, in Paramaribo, I selected five eco- 

 logical habitats in which to operate the traps: (1) At the cowbarns, 

 in a low pasture closely adjacent to swamp jungle; (2) at the center 

 of the village, high and well drained ; (3) in an opening in the jungle 

 halfway between the village and the rice-paddy section; (4) in the 

 midst of the rice-paddy section; and (5) 3 miles distant at the edge 

 of a Djoeka village. In the fifth environment, it was found, the cone 

 traps could not be operated. 



The first week, I collected as much information as I could on the 

 mosquito, fly, tick, flea, bedbug, and cockroach populations. Then 

 I began spraying the houses, outbuildings, and cattle. I started 

 with the cowbarns and cattle first in an effort to reduce the number 

 of flies that were finding their way to my dining table nearly a mile 

 distant. Every square foot of walls and ceiling of dwellings and 

 outbuildings was sprayed. Within a few days the fly nuisance was 

 no longer a problem. Horn flies and houseflies were actually difficult 

 to find. 



Various tests demonstrated the effectiveness of the new DDT formu- 

 lations against mosquitoes, cattle ticks, chigoes, fowl ticks, cock- 

 roaches, bedbugs, and other insects (19). A sheet of white paper 1 

 yard wide and 2 yards long laid down in the corner of a cool, sheltered 

 garage was examined daily for dead mosquitoes. Every day several 

 mosquitoes that had come in contact with the DDT-treated walls fell 

 on this paper. Over 900 mosquitoes were taken in a light trap over- 

 night before the village was sprayed. Beginning 2 or 3 weeks later, 

 for several months this light trap caught only a few dozen mosquitoes 

 at most. All the collecting devices in three of the stations showed a 

 marked reduction of mosquitoes. At the fourth station, in the clear- 

 ing halfway between the village and the rice paddies, there was no 

 reduction of mosquitoes ; here there were no buildings, no cattle, and 

 consequently no DDT applications within several hundred yards of 

 the collecting devices. The few data we obtained on the numbers of 

 mosquito larvae in the rice fields did not indicate any reduction. The 

 most positive control of mosquito larvae with the wettable DDT 

 powder was in the moats around the pillars of the houses. As nearly 

 as I could evaluate the control here, the eradication of Culex quin- 

 quefasciatus larvae was 100 percent and remained so when I revisited 

 the village 10 months later. 



I returned to Moengo to evaluate the DDT treatments in January 

 1947. Some of the results were beyond our fondest imagination. 



