it goes like this from Serebii.net
venipede...>> Level 22...> Whirlipede...>> Level 38...> Scolipede
glad to answer...Veronica
Venipede evolves into Whirlipede at Level 22.
Venipede evolves at level 22.
Venipede evolves into Whirlipede at level 21.
Venipede is only obtainable in Pokemon Black, White, Black 2 and White 2. But it evolves at level 22 into Whirlpede and level 30 into Scolipede.
Venipede evolves into Whirlipede at level 22 and into Scoilipede at level 30
Venipede evolves into Whirlipede at level 22. Whirlipede evolves into Scolipede at level 30
you start with venipede-whirlipede Lv.22 whirlipede-scolipede Lv.30
my venipede evolved at level 32 BUT, definitely it evolves at a lower level(oh i forget to mention that how do i know it evolve at a lower level? well that's because my venipede got like 20 levels in 1 battle)(don't ask me how but i didn't do it with hacks) good day people.
Get a Venipede (Pinwheel Forest, Lostlorn Forest) , Evolve into Whirlipede at level 22 then evolve it to a Scolipede at level 30.
Level 64
Level 43
To evolve Mantyke in pokemon black/white 2 you have to level it up with a remoraid in your party then it will evolve into mantine