746 
Journal of Agricultural Research 
Vol. XXF, No. IO 
of small community centers within a radius of 4 miles from the point of 
liberation and the towns of Garland (1,400 population) 6 miles, Rowlett 
(150 population) 10 miles, and Rockwall (1,400 population) 16 miles. 
To the west are also several community centers and the towns of Farmers 
Branch (250 population) 9^ miles and Carrollton (575 population) 10 
miles. 
Fairly direct though not heavily traveled roads lead east and west from 
near the point of liberation. The traffic on the east road outward from a 
comer 5X miles east of the point of release is heavy, being probably equal 
to that north and south of the point of release. The traps were set along 
these highways where they could be examined and rebaited expeditiously. 
The principal roads, location of towns and main streams, and their 
relation to the point of release and the recovery traps are indicated 011 the 
accompanying map (fig. 2). It will be noted that the north line of traps 
bears somewhat to the east of due north from the point of release and 
those to the south are about 2 miles west of south, while the east traps 
were about 1 mile south of east and those to the west practically due west. 
Sixteen recovery traps were utilized, four being set in each direction from 
the release point. These were 18-inch cone traps. The immediate 
environment of the traps may be described briefly as follows: West, No. 1, 
4 V* miles, under shed in cotton field, no stock near except chickens; No. 2, 
6 miles, adjacent to hogpen and near mule barn on farm; No. 3, 7 miles, 
under shed by mule barn, cow lot, and hogpen; No. 4, 8.1 miles, by crib 
next to hogpen and cow lot. North, No. 1, 4.1 miles, under hedge near 
hogpen; No. 2, 5.6 miles, in old hogpen near barn, mules and chickens 
kept; No. 3, 6.3 miles, under seed house at gin in edge of town; No. 4, 7.8 
miles, under hedge in cotton field, no stock on farm. East, No. 1, 4.7 
miles, under empty com crib, no stock near; No. 2, 6.2 miles, under water 
tank by horse bam; No. 3, 7.2 miles, adjacent to hogpen and mule bam; 
No. 4, 8 miles, in vacant shed one-third mile from main road and 100 yards 
from stock bams. South, No. 1, 4.6 miles, near house in edge of village, 
no live stock near; No. 2, 6.1 miles, adjacent to house, barns, and hogpen; 
No. 3, 7.3 miles, in shed near yards with all classes of live stock; No. 4, 
8.2 miles, under tree in edge of city. 
On September 17, the day prior to liberation, all traps were baited with 
fresh gut slime, and they were all rebaited on September 23 and 27 and 
October 3. Beginning with September 20, and continuing until Septem¬ 
ber 28, the flies were killed and examined daily in all traps. The traps 
were not emptied on September 29, October 1,2, and 4 (except No. 1 and 
2 south). October 5 was the last date when all traps were emptied and 
the last date upon which any marked flies were recovered. On October 7 
all flies in traps 2 and 3 south, and on October 8 all flies in traps 4 west and 
4 south were killed and examined, but no marked flies were found. 
