- The short answer to the question I think most people will want to know:
No, any Wurmple you catch has a 50/50 chance of evolving either into a Silcoon or a Cascoon, and there is no way to know (without cheating) before evolving the Wurmple.
- Details for those who are interested:
In Gen III - Gen V, Wurmple's evolution is determined by the Personality value, which is a hidden random number between 0 and 4,294,967,295 assigned to a Pokémon at the moment you encounter it. This hidden random number also determines some other things about the Pokémon. Different formulas are applied on this same number to determine these different attributes. See the hidden mechanics page and the Bulbabedia article on Personality values for further details.
However, the formulas are set up in such a way, that none of the attributes determined by the Personality value can be used to determine or even guess what the Wurmple will evolve into. For example both genders have a 50/50 chance of becoming either Silcoon or Cascoon. All of the 25 natures also have a 50/50 chance of becoming Silcoon or Cascoon. (As a side-note, all of the 25 natures are equally likely in any Pokémon aswell.)
In generations VI and later, a different value called the Encryption constant determines the evolution of Wurmple instead. However, this number is also a hidden number between 0 and 4,294,967,295. The same math is applied to this number instead. The encryption constant also affects a few other near-irrelevant things (see link below for details), but once again none of that can be used to predict what the Wurmple will evolve to.
As a source I used the following Bulbapedia pages:
Personality value's effect on Wurmple's evolution
Encryption constant's effect on Wurmple's evolution
