MOSQUITO CONTROL TESTS — STAGE 363 



The nuisance of mosquitoes in the village was gone. In the rice-paddy 

 area they had been absent from the dwellings for several months but 

 were being noticed again. An offer of cash for living bedbugs found 

 no takers. Horn flies and the fowl tick, as nearly as I could determine, 

 were eradicated. Cockroaches were not eliminated, but the previous 

 population of the American cockroach appeared to have been reduced 

 about 90 percent. In March 19-16, after spraying one house I counted 

 some 550 dead ones. In February 1947, after spraying this house 

 again, I counted 49, most of which were immature individuals. Ticks 

 on the cattle were greatly reduced but were not eradicated by any 

 means. (The cattle had been sprayed each month from March 1946 

 to February 1947.) All evidence indicated a 100-percent reduction 

 of chigoes breeding under the houses in the crushed bauxite. 



The most convincing evidence of the effectiveness of the wettable 

 DDT powder was obtained in the house in which I lived during my 

 first visit to Moengo. The walls and ceiling were sprayed with a 2.5- 

 percent suspension of the new formulation, although such treatment 

 leaves an unsightly white deposit. The house next door was sprayed 

 at the same time with the 5-percent DDT oil solution. Bimonthly 

 reports coming up from Surinam showed that the wettable j)owder 

 treatment remained effective longer than did the oil solution. One of 

 the first tests I made on returning to ISIoengo in 1947 resulted in cap- 

 ture of 4,000 to 5,000 living mosquitoes in a stable trap. Half of these 

 were placed in each house one morning at 9 a. m. Sheets had been 

 laid on the floor of each house, along the walls and in the corners, to 

 catch the mosquitoes, if any, that fell. At 5 that evening we reentered 

 the houses. Where the wettable DDT powder had been used, we found 

 hundreds of dead and dying mosquitoes on the sheets but none that 

 were able to rest on the walls. Ten months after application in a hot 

 and humid climate, this potent insecticide was still killing mosquitoes. 

 In the other house we found dozens of mosquitoes that showed signs 

 of DDT tremors but also hundreds on the walls that appeared well 

 and healthy. Fifty hours later I saw two living mosquitoes there 

 that appeared not to have been harmed. 



The crowning piece of evidence that DDT had really taken hold 

 in Moengo was delivered to me by William Asgerali, the British Indian 

 boy who had been assigned to me on my first visit there. Bill took 

 care of the traps and counted the mosquitoes during the months be- 

 tween my visits to Surinam. He was my interpreter, guide, tech- 

 nician, and faithful friend. When I stepped off the boat at Moengo 

 in January 1947 he greeted me with "Mister, one of the Djoekas named 

 their baby boy DDT" (18). 



