﻿10 BULLETIN 14, U. S. DEPARTMENT OF AGRICULTURE. 



(4) The disposal of the maggots is another practical consideration. 

 If the larvae were allowed to drop to the ground they would burrow 

 into it to pupate there and nothing would be gained. It would be 

 necessary to have some sort of vessel, e. g., a concrete basin, beneath 

 the trap. This should have vertical sides and contain an inch or 

 more of a weak disinfectant or of water covered with a film of oil. 

 If such a basin were connected with a sewer or cesspool the maggots 

 collecting in it could be flushed out each week without the necessity 

 of handling them in any way and without any offensive decomposi- 

 tion., 



That the maggot trap possesses certain advantages is obvious and 

 ought to lead to many attempts to develop it along practical lines. 

 Cheapness would be one of its strong points. Practically the only 

 cost would be the initial one for the construction of the trap and of 

 a basin or receptacle for catching and disposing of the maggots. 

 Very little additional time or labor would be required in operating 

 it. The sprinkling of the manure would be a very small part of the 

 daily routine of removing the manure from the stables. Proper 

 arrangements for the disposal of the maggots would require only a 

 few minutes' attention at long intervals. 



Incidentally it may be noted that the maggot trap offers a conven- 

 ient and easy means to the investigator or teacher who wishes to 

 collect coprophagous larvae in large numbers. In the experiments 

 just reported the larvae of Musca domestica L. were the most numer- 

 ous, but in addition there were also collected larvae of Stomoxys 

 calcitrans L., of Homalomyia, of certain Sarcophagidae, and doubtless 

 of others. The total numbers collected were so large that no attempt 

 was made to determine the relative abundance of the various forms. 



SUMMARY. 



Observations and experiments show that the .migratory habit is 

 deeply ingrained and highly characteristic of housefly larvae. 



The migratory habit appears in the prepupal stage in response to 

 various internal and external stimuli. 



Of the external stimuli, moisture is perhaps the most important in 

 determining the direction of their travels and the choice of a place for 

 pupation. 



The migratory habit is an adaptation of great advantage in that it 

 insures to the issuing adult the easiest and quickest escape. 



This deep-seated habit offers an important point of attack in the 

 attempts to control the pest. 



Experiments with maggot traps show that 98 or 99 per cent of the 

 total number of larvae can be made to leave the manure, provided it 

 is kept moist . Even from comparatively dry manure as many as 70 

 per cent can be destroyed. 



