151 



In the field, large populations of H. illucens may totally prevent 

 other species of flies from breeding in their midst. Control of house 

 flies on poultry farms with naturally occurring populations of H. 

 illucens was noted by Tingle et al. (1975) and advocated by Vazquez- 

 Gonzalez et al. (1962). At the tilling site, populations of house flies 

 and soldier flies were found living at different depts in the same manure 

 pack. The depths were determined by moisture level. This is an example 

 of species packing in which two or more species utilize the same re- 

 source without interference (Price, 1975). This unusual situation was 

 created when wood chips were added to wet manure. 



Soldier fly larvae are not popular with poultrymen. especially 

 after they liquidate manure and then cover the walks when migrating to 

 dry areas for pupation. This fly is not recommended as a biocontrol 

 agent in this country. Good manure management techniques should pre- 

 vent serious outbreaks of H. illucens. 



The Efficacy of Dimilin as a Feed Additive 



When fed to hens at iO ppm, dimilin produced fly mortalities of 

 lk.\l% in the laboratory and 53. 33% in the field. When fed at 1 ppm, 

 laboratory mortalities were 17.50%. Miller et al. (1975) fed dimilin 

 to hens at 6.2 to 12.5 ppm and achieved 100% control of flies. 



The addition of dimilin to feed at 1 and 10 ppm caused hens to eat 

 significantly greater amounts of feed and produce eggs at a level that 

 was numerically but not significantly higher than control hens. Eggs 

 produced by hens consuming dimilin in the diet have been found to con- 

 tain res i dues (Miller et a ! . , 1975) . Th i s , a long with the fluorine and 

 chlorine atoms attacned to the dimilin molecule (Kenaga and End, 197M, 

 has nelped to prevent dimilin from becoming labeled for commercial use. 



