This was caught in a trap that ran from 7-11 September in an open field that used to probably be sandhill habitat. The specimen is distended from the trap preservative being diluted by rain, but it is by far the biggest robber fly I've ever seen, even judging by pronotal width and head size, which should not have been affected by the dilution of the preservative . The little pencil lines in the lateral shot are 1 cm apart, and this is not any sort of trick photography, as it measures, granted in its distended state, approximately almost 5 cm. I will pin it in the future, but was curious as to what it might be, as I don't know my flies.