A European Début: The Asian Parasitoid Encarsia nipponica Targets the Invasive Aleurocanthus spiniferus in Northern Italy

In this study, the invasive orange spiny whitefly ("OSW"; Aleurocanthus spiniferus) and a species of Encarsia parasitising its puparia were studied in three different areas of the province of Modena (Emilia-Romagna, northern Italy): a pear orchard in Bomporto, an organic pear orchard in Carpi, and the semi-natural botanical garden "La Pica" in San Felice sul Panaro. The material of both species was collected for taxonomic and molecular studies. The abundance of OSW and parasitoid activity were surveyed in whitefly puparia, with a focus on the botanical garden. A total of 1800 leaves of Malus domestica, Pyrus communis and Vitis vinifera were sampled to assess whitefly infestation. The results showed a significant variation in the abundance of A. spiniferus puparia, with the highest infestation observed in V. vinifera. Morphological and molecular analyses, including mitochondrial COI and rRNA 16S for whiteflies and COI and 28S for parasitoids, confirmed the identity of A. spiniferus and identified the parasitoid as Encarsia nipponica. Molecular data also revealed the presence of three haplotypes of A. spiniferus, including a haplotype from China, new to Europe. The parasitisation rate by E. nipponica was low (0.015%). Our results provide the first European record of E. nipponica and new genetic data on the invasion pathways of A. spiniferus. Collectively, these findings offer a critical baseline for monitoring their ecological interactions and developing future pest management strategies.