Safety of Food

I use my Blaptica dubia colony pretty heavily now, and as the weather warms, I noticed last year that flies, moths, and other flying insects would hang around, and I know that the fly larvae would hatch. How bad is this? I worried that any parasites, pesticides, herbicides, etc. would find their way into/onto the roaches, which would then be fed to my scorpions.

So...bump?