Repeated island colonization by Hawaiian bark lice

The bark louse genus Ptycta is a diverse and rapidly speciating group in Hawaii, with 61 endemic species described and >150 estimated. In this study of the biogeography and diversity of the group, we are working to document the diversity of Hawaiian Ptycta, analyze relationships among Ptycta species, and investigate the geographic origin of the Ptycta colonist(s) that reached Hawaii. Preliminary DNA sequence data indicate that Hawaiian Ptycta may have diversified extremely rapidly, with a speciation rate higher than any other arthropod lineage. These data also support a double colonization of Hawaii by the genus, suggesting that Fiji or other Pacific islands may be the source of two independent invasions of Ptycta in Hawaii.