I just got the Pokedex book for Black2 and White2. You had asked about Caterpie and Weedle. You can't catch Caterpie or any of its evolutions on Black2, you can catch Kakuna and Beedrill on Route 12.
Hope that helps
I don't know I haven't completed my Black2 I stopped working on it just before the Elite 4. I had gotten a new game Final Fantasy The 4 Heroes of Light and I just now got Skylanders Spyro's Adventure they are Awesome :D
Ugh this sucks. All the people that say they have everything I'm looking for keep bailing on me or don't get back to me, this is so frustrating! You saw the ones I need right? All I need now is Groudon and Giratina. Think you can help me out? I have plenty of events I can spare.