Notes on the Pemphigine aphid Pachypappa warshavensis (Nasonov) (Hemiptera Aphididae) detected on Populus alba Linnaeus in Italy

Concurrent with the first record of the aphid Pachypappa warshavensis (Nasonov, 1894) from mainland Italy in the Emilia-Romagna region, colonies were also identified on ornamental white poplar trees (Populus alba L.) in a public park in Casale Monferrato (Piedmont region) during 2025. Species identity was confirmed by morphological features and molecular characterization using a partial COI mitochondrial gene. The described identity of the insect provides some distinctive biometric data of the sampled population. Our observations extend the known distribution of the species across various European countries. The aphid, belonging to the tribe Pemphigini within the subfamily Eriosomatinae, is an oligophagous taxon with species of Populus as primary hosts. The present study provides an overview of the aphid morphobiological profile to aid its identification, along with an updated list of potential host plants and phytosanitary remarks.