Where to Find and Catch Larvesta
From Pokemon Go Wiki
Larvesta are found and captured in Nest and Habitat locations.
Nests
Larvesta Nests are locations that consistently spawn Larvesta.
Habitats
Larvesta Habitats are spawn locations where Larvesta is likely to be encountered, but not guaranteed the way a Nest is.
Additional Tips and Information
Best Nests
If you know a really good nest or any of the nests above is really good, list them here: