How Did Japanese Beetles Come to America?

Japanese beetles are not a native species to the United States. So where do they come from and how did they get here?

Well, as their name suggests, Japanese beetles are originally native to the island nation of Japan. The beetles were spread around the world as stowaways in shipping containers, largely during the last two centuries.

Japanese beetles are first documented to have arrived in America in the state of Pennsylvania in 1916. It is believed that they arrived via a shipping container of flowers sometime before 1912, which is when inspections became mandatory in customs at port locations around the country.

Now Japanese beetles can be found nearly all over the United States, but their prevalence is highly dependent upon climate conditions and availability of food sources. They are most commonly found in America along the Appalachian mountain range and adjacent communities.