736 
Journal of Agricultural Research 
Vol. XXI, No. 10 
FIRST DISPERSION TEST NEAR DALLAS, TEX. 
On June 29, 1916, about 18,000 flies, consisting of approximately 70 
per cent Musca domestica , 25 per cent Chrysomya macellaria , 1 per cent 
Phormia regina, and 4 per cent made up of Lucilia sericata Meig., Muscina 
siabulans , Sarcophaga spp., and Ophyra spp. were liberated. These 
flies were marked just before liberation with red chalk in the manner 
previously described. The point chosen for liberation was in the coun¬ 
try about 4 miles east of the edge of the city of Dallas and within a few 
hundred feet of a large orphanage. Sixteen recovery traps baited with 
“gut slime” were set along the roads leading approximately east and 
west and north and south from the point of liberation. Four traps 
were set in each direction, the outer ones being between 2 and 3 miles 
from the point of liberation. The distance of each trap from this point 
is shown in Table II. The country covered by this radius might be 
described as a rolling, black land, farmed area. I11 general, farmhouses 
were located from >2 to 1 mile apart and most of them maintained barns 
and pigpens. The country was practically open, there being only a few 
narrow strips of woods in the area covered. The orphanage, with a 
number of dwellings and two or three stores at the corner, all near the 
point of liberation, might be considered the most attractive point for 
house flies in the area. 
The environment of the traps undoubtedly affects the character of the 
entire catch and also the tendency for flies in their dissemination to linger 
near them and perhaps ultimately be captured. For this reason the 
surroundings of each trap are briefly given. 
West, No. 1, behind small grocery store, some refuse, no barns near; 
No. 2, under tree 50 yards from dairy barn and pen; No. 3, under tree 
near farmhouse, a few head of stock kept near; No. 4, by side of dairy barn, 
favorable conditions for house flies. North, No. 1, in old pigpen near 
farmhouse; No. 2, in weeds near road and trees, farmhouse 75 yards 
away; No. 3, in cornfield, about mile from any farmhouse, no attractive 
places near; No. 4, near farmhouse and barns, about mile south of the 
village of Reinhardt. East, No. 1, under shed at gin, horses in lot and 
farm about 50 yards away; No. 2, in edge of cornfield, no buildings 
nearer than l / 3 mile; No. 3, in tall grass near small stream, nearest building 
about V 5 mile; No. 4, in old barnyard, numerous livestock in adjacent 
lot. South, No. 1, in cornfield % mile from southernmost buildings of 
Orphans' Home, no others nearer; No. 2, under shed by grocery store, 
several houses and Texas & Pacific Railway near; No. 3, in weeds in 
garden, farmhouse 40 yards away and several others in vicinity; No. 4, 
under tree, farmhouse and barns 50 yards south. 
The pike road running east and west from the point of liberation is 
heavily traveled by all kinds of vehicles, but especially automobiles. 
The road to the south has a moderate amount of travel and the road to 
