A Taiwanese Pseudasphondylia species inducing spherical leaf galls on six Neolitsea hosts, viz, N. acuminatissima, N. daibuensis, N. konishii, N. parvigemma, N. sericea and N. variabillima, was regarded as a species allied to Japanese P. neolitseae Yukawa due to similarity of gall structure and host. The Taiwanese species is morphologically different from P. neolitseae in adult palpus segmental number, shapes of pupal antennal horn, pupal prothoracic spiracle, and larval sternal spatula, resulting in its description as a new species to science, Pseudasphondylia hooki sp. n. The species delimitation (Assemble Species by Automatic Partitioning method) supported that P. hooki sp. n. is distinct from P. neolitseae. And the sistership of P. hooki sp. n. and P. neolitseae was also supported in the Maximum likelihood tree based on the 1st codon of COI region. The speciation event of them is assumed to be geographical isolation because the divergence corresponded to the separation of Taiwan and Japan in the Pleistocene. The patterns of ecological features (host species) on the phylogeny revealed that galling on N. sericea is primitive of Neolitsea-ssociated Pseudasphondylia lineage. Accordingly, the divergence pathway from north to south in Taiwan is suggested by the distributions of primitive (N. sericea) and most derived hosts (N. daibuensis).
Asphondyliina, Biogeography, East Asia, Phylogeny, Speciation
