grain mites!!!
https://entomology.ca.uky.edu/ef629
They usually ship with grains, but are activated by moisture. Too little, and the worms won't live. Too much, and mites appear. Living in the tropics doesn't help -- our ambient humidity is always high.
I have 500 darkling beetles and hardly any worms. Between constantly changing the bedding and dealing with grain mites, I'm ready to give up. I may try a layered system.
I have 500 darkling beetles and hardly any worms. Between constantly changing the bedding and dealing with grain mites, I'm ready to give up. I may try a layered system, or if you are having success -- whatever it is you're doing.