I'm with Ryan. Phileurus truncatus has two large horns sticking out of its head (even female has them) while P. valgus lacks these horns.
Hope the specimen in the picture is a mated female
I used to keep these guys and I enjoyed them (Unfortunately, I failed to breed the second generation because I gave most of them away to my friend and he failed to breed them
You guys are right! I actually found some Phileurus truncatus the other day and they are very different as far as size and horns. Look at the topic above.