Hey, this might just seem like a newbie question but when talking about crossing sub-species does this refer to the locality of the snake? I just ask this because many of the snakes I've seen up for sale aren't local specific eg stimmies (have stimsons even been classified into subspecies?), so then if there was an intent to breed from it you wouldn't actually know the sub-species.
In an ideal world, when someone formally describes a subspecies they should provide enough information to let someone else identify that subspecies. So if you bought an animal as
Antaresia stimsoni and you want to know if you've got the
A. s. orientalis subspecies or the
A. s. stimsoni subspecies, you should be able to get the original description of the subspecies and compare the characteristics the author used to differentiate the new subspecies (in this case
A. s. orientalis) from the 'original' type (
A. s. stimsoni).
The characteristics used to differentiate subspecies will generally be morphological (e.g., one subspecies has <220 ventral scales and the other has > 220 ventral scales). My understanding is that it's not enough to just say subspecies A occurs in the west and subspecies B occurs in the east. It may be the case that the two subspecies are found in different areas (in fact, I think it would be unusual to find two subspecies living in the same area), but there need to be additional points of difference before the subspecies will be widely recognised.
For those of you playing at home, I believe the publication in which the two
A. stimsoni subspecies were first described is:
Smith L A 1985. A revision of the Liasis childreni species-group (Serpentes: Boidae). Records of the Western Australian Museum 12 (3): 257-276
I don't have a copy of this article, so I can't tell you what the differentiating characteristics are.
Does that answer your question in a long-winded fashion?
Stewart