A MAGGOT TRAP IN PRACTICAL USE. 5 
But this number does not represent all that dropped out of the manure 
into the water below. A flock of young turkeys roamed at large 
during the summer over the college grounds and adjoining fields. 
Having once found the maggot trap they made frequent visits and 
! were seen to devour the larvsa with great avidity, sometimes com- 
pletely clearing the floor except where the water was more than 2 or 3 
inches deep or when it was so badly discolored as to conceal the larvae. 
Sparrows also were seen frequently on this floor, but one could never 
get close enough to see whether they actually devoured any larvae or 
not. It is more than likely that they did. The actual number of 
larvae which were destroyed by the maggot trap was undoubtedly 
much greater than 112,000. 
After October 1 the writer and an assistant examined all the manure 
on this platform in search of puparia. The manure was thrown off, 
| a few bushels at a time, onto a smooth concrete surface near by and 
I very carefully examined, all straw being shaken out and all solid 
parts being finely broken up. In a very literal sense this was like 
looking for a needle in a haystack. A few scattered puparia were 
seen in various parts of the heap, but in only two spots were they to 
I be found in the characteristic clusters or "nests" which can be found 
so readily at the edges of manure piles on the ground. These two nests 
were found at the end of the platform where the most recent additions 
had been made. The manure at this end had not been sprinkled 
with water after the day it was put on. Failure to keep this moist 
] as long as larvae were present is, in the writer's opinion, the explana- 
tion of the pupation in this part. One nest contained about 400, 
and the second about 700 puparia. Allowing for some that may have 
escaped notice, the number of puparia may be given in round numbers 
as 1,500. No larvae whatever were found in any part of this heap, the 
oldest part of which had been on the platform for two months, and 
even the freshest portion of which had been standing for at least 10 
days before it was examined. If, then, 1,500 represents the total 
number which pupated in the manure and 112,000 the number 
which was destroyed by drowning, it shows a percentage destruction 
of about 98.5 per cent of the possible total. This is illustrated in 
figure 2, above. Taking into account the larvae devoured by 
turkeys, etc., it is probable that the effectiveness of the trap could be 
I rated as above 99 per cent. 
In a former bulletin the claim was made that manure will be prac- 
tically free from maggots after standing 10 or 12 days. Special 
attention was given to this point during the course of the experiment, 
and all observations tended to support the claim. Moreover, there 
was no evidence that larvae ever migrated from the fresher portions 
of the manure to the older parts to pupate. That old manure 
does not serve as a breeding place for flies is a point that deserves 
