Abstract: The spiraling whitefly (SWF), Aleurodicus dispersus Russell, is an important agricultural and forest pest in Hainan province, southern China. In this study, we sequenced and analyzed the gene sequences of mtDNA-COI and rDNA-ITS1 genes within A. dispersus populations from 16 districts in Hainan. The results showed that mtDNA-COI gene sequences of the spiraling whitefly populations from different regions of Hainan were identical, except Wenchang sample coming from Psidium guajava carrying one variable position (C-T) at position 476 bp in mtDNA-COI gene. Analyses of the rDNA-ITS1 gene showed that the ITS1 sequences of all the A. dispersus populations were consistent. The phylogeny trees of A. dispersus populations based on mtDNA-COI gene showed that fairly low genetic variation existed among the different populations sampled in various locations. Taiwan population and Hainan population had a fairly closed relationship according to the phylogenetic trees, suggesting that the invaded A. dispersus in Hainan likely originated from Taiwan. Aleyrodidae could be divided into two subfamilies, i. e., Aleurodicinae and Aleyrodinae, according to the phylogenetic trees of different whitefly species based on mtDNA-COI and rDNA-ITS1 gene sequences, which is consistent with the results of former studies.

Key words: Aleurodicus dispersus, mtDNA-COI, rDNA-ITS1, phylogenetic tree, genetic differentiation, variation