Inventory of arthropods of the west slope shrubland and alpine ecosystems of Haleakala National Park

Abstract

On Maui, shrubland and alpine ecosystems occur in and around Haleakala National Park (HALE) on the mountain’s upper west slope, upper south slope, and within the crater (actually a large erosional depression). The arthropod fauna of these areas has been studied on numerous occasions, including a relatively exhaustive inventory in the mid- 1970’s. These and other collections have ensured that the endemic arthropod fauna in HALE’s subalpine shrubland and alpine aeolian zones is relatively well known. While new endemic species continue to be found, the fauna in well-studied taxonomic groups is probably relatively complete. In contrast, the introduced fauna continue to grow by virtue of continual new introductions, and repeated inventories (i.e. monitoring) are the only way to measure the rate of this growth and to make early detections of particularly destructive species. We conducted an inventory of arthropods in shrublands and alpine habitats on Haleakala’s upper west slope and summit using three systematic sampling techniques in two elevational zones, supplemented by limited opportunistic hand collecting. This report catalogues all arthropod species collected in the course of the inventory, and when possible, provides additional information relevant to the species listed. We assess inventory completeness and the relative effectiveness of the different sampling techniques. We also make limited comparisons between our inventory, which took place between 2001 and 2004, and the most recent similar effort, conducted in 1975 to 1977.