328 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



directions from the release point indicated that the winds probably 

 had not had much effect on the flight of the flies. 



On 75 days of the 94-day-long experiment 19,580 female flies were 

 stained and released. Collections were begun the day following initial 

 release of stained flies. In all, 18,707 flies were collected during 711 

 visits that were made to the various stations around the release point. 

 These were observed through a dissecting microscope as they were 

 passed, one at a time, into a solvent composed of absolute alcohol, 

 glycerine, and chloroform in the proportion of 3 to 2 to i. Of the 

 total, 21 were stained flies. These included 9 ochraceum, 8 metallicum, 

 and 4 callidum. They were recovered at distances ranging from 2.1 

 miles up to 7.4 miles from the release point (map 15). These, of 

 course, do not represent the actual distances traveled by the recaptured 

 flies. Considering the extreme irregularities of the terrain, some of 

 the ravines traversed being over 500 feet deep and over a mile across, 

 it is quite probable that the flies had landed several times and that 

 the distances noted should actually be much greater. One stained 

 metallicum was recovered 3.8 miles from the release point the day 

 following initial release of stained flies. This suggested a very rapid 

 flight and the likelihood that the flies travel great distances. 



Since the results of these flight-range studies were rather surprising, 

 Dalmat (1952a) repeated the experiment in another area (Munici- 

 pality of Acatenango, Chimaltenango, Guatemala) to confirm the 

 original findings. The techniques were the same as in the first study. 

 During the period of the experiment, the winds shifted a good deal 

 but generally prevailed toward the northeast. Since stained flies were 

 recaptured as much to the south and west of the release point as to 

 the north or east, it was considered that the flight of the flies was either 

 not affected or only negligibly affected by the winds. A total of 

 66,544 female flies was stained and released. In all, 52,685 flies were 

 collected during 1,510 visits to the 33 collecting stations. Of this num- 

 ber, 31 were stained flies, one being ochraceum and all the others 

 metallicum. The flies were recovered from i.o to 9.7 miles from the 

 release point, as compared with 2.1 to 7.4 miles in the 1949 experi- 

 ment, the distances being measured as straight lines on the map. 

 Diagrammatic profiles, drawn to scale from actual measurements of 

 the contours of the ground, were presented (Dalmat, 1952a) in order 

 to give a more accurate representation of the terrain traversed by the 

 flies, as well as of the actual distances between the release point and 

 the various stations at which stained flies were recaptured. 



Longevity study. — Dalmat (1952a) presented the first experimental 

 data concerning the longevity of female Simuliidae. The experiment 



