The Western Conifer-Seed Bug is a true bug native to the pine forests of western North America that has quickly spread eastward since the 1950s. Pest specialists surmise that these bugs were accidentally introduced to eastern North America through wooden shipping crates on trains or through commercial Christmas trees. After becoming established in eastern North America, they were repeatedly introduced across Europe, Asia, and northern Africa. By the late 1990s, the Western Conifer-Seed Bug was recorded in Northern Italy and has since been found on almost all continents with the exception of Antarctica.