Complex sentence: However, published accounts of the periodical cicada's life cycle describe the history of cicada sightings differently, citing reports of fifteen to seventeen year recurrences of massive numbers of emergent cicadas written as early as 1737.
Split into simpler sentences: However, published accounts of the periodical cicada's life cycle describe the history of cicada sightings differently. These accounts cite descriptions of fifteen to seventeen year recurrences of massive numbers of emergent cicadas that people had written as early as 1737.