I have 5 pogonomyrmex subdentatus colonies, about 4 months old. All of them have had random worker die offs, and the larger colony has probably lost 30% of total workers produced (10+workers). They just appear dead in the outworld. I've included pictures of their setups-just test tubes with cotton and a grout outworld. I give them large amounts of kentucky bluegass seeds as well as mealworms. The only thing that stands out to me is possible dehydration? But they have test tubes full with water and the queens seem to be fine. They are kept in an incubator at 82-86 degrees, are activevly foraging out and about and seem otherwise healthy.
I'm really devastated and would appreciate any input. Thanks.
Since the first pic I've moved them into a new test tube with clean water but no difference.