267, I haven't heard of anyone having a robust colony of BSF that had a housefly problem. From what I've read this is even true in open waste like outhouses and under chicken coops. Can you give me an idea of the density of your colony?
Other species of flies are always present whenever you start a new colony. BSF are a little slower at reproducing than houseflies. BSF eggs take 4 days to hatch while housefly eggs hatch in a day or even less. Once the BSF find your unit and lay eggs they begin to dominate the food scraps within a week or two and normally you stop seeing pest fly reproduction at that point.
