Review of the native Hawaiian leafhopper genus Nesophrosyne (Hemiptera: Cicadellidae: Deltocephalinae) with description of eight new species associated with Broussaisia arguta (Hydrangeaceae).

A review of the native Hawaiian leafhopper genus Nesophrosyne (Hemiptera: Cicadellidae: Deltocephalinae) is presented. Specimens were examined from across the entire Hawaiian Archipelago, Nesophrosyne is redescribed, and the subgenus Nesoreias is synonymized with Nesophrosyne. Eight new species associated with the widespread host plant species Broussaisia arguta are described: N. heopoko sp. n. from Kaua'i; N. makaihe sp. n. from O'ahu; N. magnaccai sp. n. from Moloka'i; N. broussaisiai sp. n., N. ogradyi sp. n., and N. kaupoi sp. n. from Maui; and, N. aakokohaikea sp. n. and N. kanawao sp. n. from Hawai'i Island. Morphological and molecular characters were employed to delineate new species. Populations associated with B. arguta on different islands, individual volcanic mountains, and discrete geographic areas represent reciprocally monophyletic species. A monophyletic complex of five sibling species, morphologically cryptic on individual islands, were identified from Maui and Hawai'i Island. The kanawao species group is erected for these species and is further subdivided into two species subgroups based on monophyly, island endemicity, and morphology: broussaisiai species subgroup containing N. broussaisiai, N. ogradyi, and N. kaupoi on Maui; and, aakokohaikea species subgroup containing N. aakokohaikea and N. kanawao on Hawai'i Island.