Gromphadorhina descriptions were based primarily on the horn structure of the male, I've seen some of the original descriptions. I'd love to see that schema of hisser genitalia in a scan. Original descriptions based on variable horn structure, pronotum shape and surface texture is why stocks I sent specimens of to a cockroach taxonomist identified as G. portentosa, G. oblongonota, and Princisia all interbreed readily in captivity. They probably are just geographic races and may not even qualify as different subspecies. It is not that people misidentify them, the original "Princisia" never existed and was simply a taxonomic error of someone trying to use a variable specific character as though it were a stable generic character (the notch in the pronotum) without checking to see the male genitalia were identical. However, this does not mean there are not a number of unique stocks that vary in appearance and specific husbandry.