6 
BULLETIN 14, U. S. DEPARTMENT OF AGBICULTUEE. 
iii the hope that they may be of some interest to others they are here 
reported in some detail. 
A large galvanized iron pan, measuring 5 by 3 feet, with sides 4 
inches high, was made. In this stood a container on legs 8 inches 
high. This container measured 4 by 2 by 2 feet. The sides and bot- 
tom were of heavy wire, ^-inch mesh, supported by a light wooden 
framework. Twelve cubic feet of manure well infested with eggs and 
larva? were placed in this container and sprinkled with water. Water 
was also poured into the pan below to the depth of about 1 inch. 
Surrounding and covering both pan and container was a fly-tight 
inclosure made of a large cage, 6 by 6 by 6 feet. This prevented 
further infestation of the manure, and an arrangement of traps at 
the top of the cage made it possible to capture and keep a record of 
any flies that might emerge. At the time for the emergence of flies 
the sides of the cage were darkened with black cloth in order to 
drive the flies into the traps at the top. Each day the larvae were 
collected from the pan and counted, and each day the manure in 
the container was sprinkled thoroughly with water and the pan was 
washed out and again partly filled with water to drown the larva? 
which fell into it. The records of Experiment Xo. 1 are summed up 
brief! v in Table I. 
Table I. — Migratory habit of housefly larvse; Experiment J\o. 1. 
Date. 
coated ™-2T 
from pan. XTZ ^- 
Larvae 
Date. collected 
from pan. 
Flies from 
traps. 
1913 
Aug. 27 
28 
29 
30 
31 
Sept. 1 
2 
3 
4 
5 
337 
1913 
Sept. 6 
88 
102 
23 
19 
9 
5 
6 
715 ! 
1.550 
S 
110.000 : i 
9 
iS,000 
10 
2,160 
12 
670 j 3 
263 18 : 
(2) 8 
304 22 
15 
23,999 
303 
Approximate. 
2 Collected on following day. 
A few flies at the time of emergence fell into the water of the pan 
and were drowned. Allowing for these and for the few which may 
have escaped from the cage during the opening and shutting of the 
door, the total number of flies may be placed at 350. It will be seen 
from these figures that out of a possible total of 24,350 24,000, or a 
little more than 98 per cent, were destroyed through the catching of 
the larva? in the manner described. 
A second experiment was started on September 16. The manure 
used was from the same source as in the first experiment and con- 
tained practically the same proportion of straw. The same amount 
was used, viz, 12 cubic feet. The only respect in which this experi- 
