Complex sentence: The common european hornet has also been accidentally introduced to North America about the middle of 19th century, and has lived there since about the same latitudes as in Europe, however it has never been found in western North America.
Split into simpler sentences: The common european hornet was accidentally introduced to North America about the middle of 19th century, and has lived there since, at about the same latitudes as in Europe. However, it has never been found in western North America.