Emerged from a Datana major pupa. I tried to raise several caterpillars from the same brood in August 2018 that turned out to develop at vastly different rates and from which I found only two seemingly healthy pupae in the litter I had provided (I have no idea what happened to the others). Pupation must have occurred early September, and at the end of the month one pupa produced the tachinid fly shown here. The other I hoped to provide me with a moth next summer at the time one would expect for Datana major. Instead, another fly! The two flies look to me to be the same species, and I am mystified by their different times of emergence. Where can I read about this?