Hi!
Cocci... I use starter medicated with Amprol for all my chicks/ducklings and it is still necessary certain times of the year to put chicks on Sulmet. I was under the delusion that the starter with Amprol would prevent Cocci altogether, but I read that that isn't effective until they are older.
That bit of rain we had, and within a day I could see symptoms, so I started all the chicks under 6-wks on a round of Sulmet.
Mealworms... Ants got in my mealworm bins and I scrapped them.
Soldierflies... Before the ants found them, I was 'harvesting' a couple hundred larvae a day from my bins. Like with the mealworms, I got tired of fighting the ants.
I like Soldierflies better, because they are not so 'specialized'.