Decodon
Guides
Papaipema sulphurata
Water-willow Stem Borer, Decodon Stem Borer, Swamp Loosestrife Borer Moth
Papaipema sulphurata is a noctuid moth endemic to southeastern Massachusetts, including Martha's Vineyard and Nantucket. The species is an obligate specialist on Decodon verticillatus (water-willow or swamp loosestrife), with larvae that tunnel into stems and feed on vascular tissue. Adults fly in autumn, with a wingspan of 32–38 mm. The species is considered rare due to its restricted range and specific host plant requirements.