Mango Hawk Moth

On Aug 14, 2018 a family member (who lives just a few kilometers from our house) brought me a very large caterpillar in a paper bag. He explained that it had crawled into his house and his first thought was to bring it to me. It was truly huge, the body was 9 cm. long and the tail horn was 3.2 cm. I had never seen anything like it before, but immediately thought it must have something to do with mango trees as the house it came from sits under the canopies of several mangoes. At that time I was captive rearing Green Hawk Moths - Pergesa acteus from eggs and releasing them into the wild. All my available cages were stacked with P. acteus and I had no spare capacity. However, this strange big caterpillar, obviously some kind of hawk moth, appeared to be pupating. It was dark brown and very lethargic. It was not interested in eating any of the variety of leaves I offered it. So I made a decision to place in a cage occupied by a number of P. acteus which were close to pupating. On the morning of 4 Sept., at around 6:00 a.m., I noticed that one of the original occupants of the cage had eclosed and was climbing up the mesh of the cage. So I opened the top to let him fly away whenever he was ready (they always need considerable time to inflate their wings and discharge excess fluid left over from their pupation) and I left it like that. I went off to make a coffee and returned around 6:15 a.m. and was absolutely astonished by what I saw. The big moth had also eclosed and climbed up the mesh and was resting beside the P. acteus. I had posted a picture of this to give a better idea of the difference in size. Only then was I able to identify it.