1916] Reducing Malaria 277 



at these and other stations mosquitos sprayed with aquaeous 

 anilin dyes, it was determined that the big influx of albimanus 

 came from the extensive breeding area in the Rio Grande. The 

 data concerning flight is reserved for a future report. 



Exact counts were made of the mosquitos caught in traps 

 and inside of houses; these counts are differentiated as "trap 

 catch" and "hand catch" respectively, and are further divided 

 into two groups, "Anopheles" and "Culex spp, " the latter 

 representing all non-anophelin«. All counts were made daily, 

 but in the results presented in this article, this data is greatly 

 simplified. The trap catch represents those mosquitos which 

 entered the Chas. H. Bath type of insect trap affixed to build- 

 ings. This trap is described in my previous paper (Ann. Ento. 

 Soc. Am. vol. VI No. 1). These traps were placed on the sides 

 facing S-W and N-E. The method of catching mosquitos 

 inside of barracks is also described in my former paper. Although 

 the cheapest labor was used, W. I. negroes, this work could 

 hardly have been done better. 



EFFECT OF TIL\PS AFFIXED TO BUILDINGS ON THE NUMBER OF 

 MOSQUITOS WHICH ENTER THE BUILDINGS. 



Two buildings were used to determine this influence. The 

 following table gives a comparison of these two buildings : 



Camp 5. Camp 15. 



Contains 75 W-I negroes. Contains 75 W-I negroes. 



Two doors opening to exterior. But one door opening to exterior. 



Four traps. No traps. 



Nearest to breeding area. Farthest away from same. 



Of total mosquitos caught in both Of this same total, this camp 



camps, this camp's share was claimed 67%. 



but 33%. 



This comparison shows that both buildings are practically 

 the same, excepting that one has traps while the other has none. 

 The building farthest away from the breeding place, and with 

 but one- door, had 67% of the total mosquitos caught in the 

 two camps. 



The record was kept of the cases of malaria reported from 

 each of these camps. During the 175 days representing this 

 record, 29 cases came from camp 15 (without traps) and but 

 12 cases from camp 5. It may be said that there is no conclusive 

 proof that these cases had their origin from the mosquitos 

 present inside of the barracks. But granting this, it surely 



