Volbeat and Illumise, the Firefly Pokémon, as well as their Shiny counterparts are available in Pokémon GO. If you’re lucky, you may encounter a Shiny Volbeat or a Shiny Illumise in the wild. Volbeat is usually found only in Europe, Asia and Oceania, while Illumise is usually found only in the Americas and Africa. Niantic recently announced that both Pokémon have swapped locations, but the developer has since deleted this mention.
Source: Official Pokémon GO blog
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