Route 24, Route 25, Viridian Forest — 3 locations on the interactive map.
Azalea Town, Ilex Forest, Lake of Rage, National Park, Route 2, Route 24, Route 25, Route 26, Route 27, Route 30, Route 31, Route 34 and 5 more — 17 locations on the interactive map.
Caterpie → Metapod (Level 7) → Butterfree (Level 10)