Biogeography and phylogenetics of Hawaiian bark lice

In a redefinition of the genus Ptycta (Psocidae), the history of the genera Ptycta Enderlein, 1925, and Copostigma Enderlein, 1903, is assessed. Previously defined as a monophyletic complex based on male genital morphology, Ptycta is redefined as those species of the Ptycta-Copostigma complex with forewing veins Rs+M fused for a length. Two new species of Ptycta from Japan are described, P. recava sp. nov. and P. johnsoni sp. nov., increasing the number of Japanese species to four, along with P. parvidentata Tsutsumi, 1964, and P. micromaculata Thornton, Lee, and Chui, 1972. Distributional information and illustrations of each species, and a key to Japanese species of Ptycta are included. Ptycta has diversified in the mid- and high-elevation forests of the six main Hawaiian Islands. To investigate the diversity, distribution, and evolutionary history of the group, I used morphological characters of the male genitalia, wings, and head, and DNA sequences of the nuclear gene wingless and mitochondrial genes 12S, 16S, and COI. Molecular and morphological data indicate that the ~50 species of Hawaiian Ptycta are a monophyletic group. The lineage includes two well-supported clades that are united by two synapomorphic characters of the male genitalia. The two clades are likely the products of a single colonization event and include many independent lineages with radiations within and between islands. The Hawiian Ptycta is likely slightly less diverse than previously described, with an estimated diversity of 40 species, rather than the 61 taxa previously. These data also suggest that the lineage originated in the west or south Pacific region. Further, I revise the systematic status of subfamily Kaindipsocinae (formerly Kaindipsocini) based on morphology of the male terminalia and on molecular data. Clematostigma, Lasiopsocus, and Tanystigma are newly assigned to this subfamily, and a new tribe, Clematostigmini, is established for these genera. The Blaste lunulata species group is also placed within Kaindipsocinae and is probably closest to Kaindipsocus. Both morphological and molecular data provide strong support for monophyly of Kaindipsocinae and molecular data support a sister relationship between this subfamily and the rest of Psocidae