This is an interesting “pair” of very similar-looking tachinids. One is Xanthoepalpus bicolor, a very distinctive species from the southern United States (this one is from Greenlee County, AZ). The other was collected in Ecuador (Napo, Rio Hollin, 1350m ASL) by Andrew Neild. There are no keys to this part of the world but after looking at the NHM collections in London it looks very similar to Epalpus (Oxyepalpus) flavoscutellatus Bischef, a species recorded previously from Brazil. There are many similarities but the main difference that I could see were the arrangement of discal & marginal bristles on T3 & T4.
EDIT: Monty Wood has suggested that Oxyepalpus is likely to be reduced to a synonym of Epalpus.