I was raising monarch caterpillars this year. I got them as eggs. Everything was going fine. I have four in a chrysalis. They formed on/around August 16th (ten days ago). Yesterday it was very hot and in the evening I noticed that they had black splotches on three of the four of them. Is this OE? Is this symptoms of a tachnid fly? They were all kept inside the house.
Any help would be greatly appreciated.