black soldier fly
The fly is harmless. The BSF larvae are very common in compost piles and especially worm bins and are an important part of breaking down scraps into humus.
BSF larvae are beneficial in the following ways:
Prevent houseflies and blowflies from laying eggs in the material inhabited by BSFL. In a typical BSFL colony there will be no maggots from these species.
Black soldier flies don't fly around as much as houseflies. They are very easy to catch and relocate when they get inside a house, as they do not avoid being picked up, they are sanitary, and they do not bite or sting. ...
Significant reductions of E. coli 0157:H7 and Salmonella enterica were measured in hen manure.
Quickly reclaim would-be pollutants: Nine stinky organic chemicals were greatly reduced or eliminated from manure in 24 hours.
Quickly reduce the volume and weight of would-be waste: The BSFL colony breaks apart its food, churns it, and creates heat, increasing compost evaporation...