Reference
Joanna Trela, Lukasz Junkiert, Karina Wieczorek (2020): Sexual morphs of the three native Nearctic species of the genus Periphyllus van der Hoeven, 1863 (Insecta: Hemiptera: Aphididae), with identification keys including introduced species – Bonn zoological Bulletin - früher Bonner Zoologische Beiträge. – 69: 95 - 103.