Presence of Aleurocanthus spiniferus (Quaintance, 1903) haplotypes in Croatia

The orange spiny whitefly, Aleurocanthus spiniferus (Quaintance, 1903) (Hemiptera: Aleyrodidae), is a quarantine invasive pest of concern in the European Union. In Croatia, it was first detected in 2012 and afterwards reconfirmed in 2018. This study aimed to characterize the genetic variability of A. spiniferus in the southern coastal region of Croatia, specifically within the Dubrovnik–Neretva and Split–Dalmatia counties, using mitochondrial cytochrome c oxidase subunit I (COI) sequences from samples collected between 2019 and 2020. Two dominant haplotypes, H1 and H2, were identified in 8 samples from different host plants and locations in Dubrovnik-Neretva and Split-Dalmatia counties. Haplotype H1 was prevalent on the Hvar Island, whereas H2 was primarily detected along the mainland coastline. The coexistence of both haplotypes suggests multiple introduction pathways, likely through plant material trade and possible natural spread from Montenegro. The neighbouring obtained results provide a basis for comparison with haplotypes in countries and with those from the pest’s native range, which may contribute to clarifying the origin of populations in Croatia and suggest whether they result from a single or multiple introductions.