Region Exclusive: Heracross
As like the Mainstream Pokemon Games where some Pokemon are exclusive to a given Version of a Game, so something similar is found within Pokemon GO. Instead, however, a handful of Pokemon are exclusive to a given region or country in the world. Within the 2nd Generation of Pokemon GO, there are two different Pokemon that are Region Exclusive.
Of these two Pokemon, one of them is heracross. But unlike most of the 1st Generation Region Exclusive Pokemon, Heracross isn't exactly set to one given country. After the 2nd Generation Update, many experts believed Heracross was exclusive to only South America. Although this is true for the most part, oddly enough, there were some players in southern Florida finding Heracross. After a little homework, it was discovered that the so-called Tauros Line (at 29 Latitude) had now become the Tauros/Heracross Line. Any area above said Latitude is where Tauros can be found, where as any area below this point would find Heracross (including Southern Florida, South America, and the Southern Tip of Texas).
Since Trading has yet to be incorporated in Pokemon GO, the only realistic way of obtaining heracross is by visiting one of these given areas. Sometimes there may be given events that are held which will see certain Region Exclusive Pokemon being found in other areas of across the globe, but said events are unpredictable. It was also once believed that a player could find Region Exclusive Pokemon of other countries in Pokemon Eggs, but that concept has since been deemed impossible.