Susceptibility of Endemic Myoporum (Naio) Species and Populations to Klambothirps myopori in Hawai‘i

An invasive thrips species (Klambothrips myopori, Thysanoptera), originally from Australia, attacks and inflicts severe damage to endemic Myoporum species in Hawai‘i. There is concern that the thrips will cause local extinctions of Myoporum in Hawai‘i. This study examined susceptibility of different Myoporum populations from various Hawaiian Islands to K. myopori infestation and dieback of aerial plant parts. Experimental exposures of plants from different populations were conducted in common garden studies. All M. sandwicense populations included in the study were highly susceptible to infestation and severe dieback of leaves and shoots occurred. Plants from a single M. stellatum population were less susceptible to attack and subsequent dieback of stems. Management options for populations under pressure from K. myopori are discussed.