﻿THE MIGRATORY HABIT OF HOUSEFLY LARVAE. 



ment differed from the first was in the fact that the manure in the 

 container was not sprinkled with water at any time, except for a 

 light shower on September 19 and another on September 22. Much 

 of this rainfall failed to reach the manure in the container because of 

 the covering of the cage. A comparison of the results of this experi- 

 ment with those of the first indicate the importance of moisture as a 

 stimulus. 



Table II. — Migratory habit of housefly larvae; Experiment No. 2. 



Date. 



Larva?, 

 collected 

 from pan. 



Flies 

 caught 

 in traps. 



Date. 



Larva? 

 collected 

 from pan. 



Flies 

 caught 

 in traps. 



1913 

 Sept. 17 

 18 

 19 

 21 

 22 

 23 

 24 

 27 

 28 

 29 



15 

 132 

 168 

 894 

 427 



35 

 





1913 

 Sept. 30 

 Oct. 1 

 2 

 3 

 4 

 6 

 7 

 8 





64 

 80 

 125 

 52 

 78 

 84 

 44 

 22 



























43 

 43 

 33 











1,671 



668 







Allowing for the few larvae and adults which may have escaped, 

 the totals may be given in round numbers as 1,700 larvae and 700 

 adults. Thus from a possible total of 2,400, 1,700, or about 71 

 per cent, were destroyed. In passing it is unnecessary to point out that 

 here 700 flies did pupate in the manure in spite of the fact that they 

 had every opportunity to leave it. 



With the approach of cold weather the work against the housefly 

 was transferred to the experiment station at Audubon Park, New 

 Orleans, La. Some other experiments of a similar nature were car- 

 ried out here with smaller containers and cages. The strong wire 

 baskets of the kind commonly seen in markets and stores for the 

 display of fruits and vegetables made first-rate "maggot traps." 

 The baskets used were 16 inches in diameter and 16 inches high 

 and stood on legs 9 inches high. A galvanized-iron pan 2 feet square 

 was made for this to stand in, and over all this was placed a cage 

 consisting of a light wooden framework covered with black cloth. 

 .The top of the cage was covered by boards in which was an opening 

 for the attachment of flytraps. 



The third experiment was started on November 13. The basket 

 was filled with manure taken from stables on November 12. The 

 manure, which contained very little straw or bedding of any kind, 

 was packed firmly in the basket and sprinkled with 4 quarts of water. 

 The iron pan below was partly filled with water. The cage with its 

 traps was not put in place until November 18, thus exposing the 

 manure to possible infestation for a period of five days. The manure 

 was sprinkled daily as long as larvae appeared. 



