Black soldier fly (Hermetia illucens (Linnaeus, 1758)) larvae inhibit oviposition of house fly (Musca 
domestica Linnaeus, 1758) by releasing a semiochemical, although in some situations, inhibition is 
only partial. We hypothesized that there is a certain period in the life cycle of black soldier fly when it 
can cause antibiosis of the house fly. Choice and non-choice tests were used to separately examine the 
effectiveness of each developmental stage of black soldier fly (egg, larval (phase I, II, and III), prepupal 
and pupal stages) and crude extract of larvae on house fly oviposition. Tests using each developmental 
stage were compared with controls lacking black soldier fly. The effects of black soldier fly on the number 
of newly hatched house fly larvae were evaluated and there was a significant difference between the 
test and control in the number of eggs laid by house fly for all phases of the black soldier fly larval 
stage. Strong inhibition was found in some black soldier fly larval phases. Significant differences in the 
numbers of house fly eggs oviposited in food containers treated with crude extract were found when 
compared with a control, confirming that chemicals from black soldier fly larvae resulted in inhibition 
of oviposition of house fly. The results from experiment also indicated that chemicals from black soldier 
larvae influenced the number of house fly larvae newly hatched from eggs.