Research on the Diptera of the Hawaiian Islands dates to the last half of the 19th century and was first summarized in the Fauna Hawaiiensis (1899-1910) series (Sharp 1899). Zimmerman's multivolume Insects of Hawaii series (1948-2003) has also added greatly to our knowledge of the endemic and introduced insect species present in Hawaii (Zimmerman 1948). The Proceedings of the Hawaiian Entomological Society and the Records of the B. P. Bishop Museum are two other venues that were used by Hawaiian entomologists to publish shorter works or updates on new species, new invaders or new island records. It was from these works that the Bishop Museum created a comprehensive checklist of the Terrestrial Arthropods of the Hawaiian Islands (Nishida 2002). My lab has been conducting collections and surveys in Hawaii as part of various projects for over 15 years. As a result, we have many new species and new island records and have generated a number of new identification tools for several fly families. The goal of this multipart series is to publish these data in an accessible format to facilitate further research on Hawaiian Diptera. Future papers will focus on new island records and identification tools for Dicranomyia, a description of a new species of Procancae with a revised key to the genus, and new island records for Scatella.

Asteiidae are a small family of acalyptrate flies, containing approximately 130 species worldwide. There are 11 genera in the family but over half of the described species belong to a single genus, Asteia (Sabrosky 1956, Sabrosky 1957, Sabrosky 1987). The ecological associations of this group are unclear, although members of this family have been reared from a variety of substrates, including fungi, frass, bleeding trees and dried stems (Sabrosky 1987).

The most recent revision of the Hawaiian Asteiidae (Hardy and Delfinado 1980), lists three genera, Asteia, Bryania, and Loewimyia, as well as a comprehensive key to Hawaiian members of this family. Bryania and Loewimyia each contain a single species from Hawaii and are uncommon in collections. Hardy and Delfinado (1980) considered Bryania bipunctata, the only species described in this genus, an endemic species from the Northwest Hawaiian Islands. The relationship of Bryania to the other Hawaiian asteiids remains unclear. They described Loewimyia orbiculata as a new species from Oahu but did not comment on whether or not they considered it to be endemic (Hardy and Delfinado 1980). The genus Loewimyia is known only from one other species found only in North America so it may be a migrant. Members of the genus Asteia are the largest and most commonly collected asteiids, comprising nine of the eleven Hawaiian asteiid species (Table 1).

Many Hawaiian radiations are characterized by a high degree of single island endemism. For example, >95% of the ~300 species Hawaiian Campsicnemus (Diptera: Dolichopodidae) are single island endemics (Evenhuis 2008) and approximately 85% of the 1000 Hawaiian Drosophila (Diptera: Drosophilidae) are also found on just one island (Evenhuis 2008, O'Grady et al. 2009). In contrast, smaller groups like the genus Dicranomyia (Diptera: Limoniidae) have less than 30% of species endemic to a single island (Nitta and O’Grady 2008, Goodman and O'Grady 2013). According to the latest revision of the Hawaiian Asteia (Hardy and Delfinado 1980), seven of the nine described species (78%) are single island endemics. However, recent collections demonstrate that only three of the nine (33%) known species are endemic to a single island (Table 1).

Literature Review

Collection Methods

We would like to thank the editor, Dr. Torsten Dikow, and three reviewers, Drs. Neal Evenhuis, Wayne Mathis and Curtis Ewing, for helpful suggestions on the mansucript. We would also like to thank Drs. Daniel Rubinoff and Lub Lebalnc of the University of Hawaii Entomology Collection for assistance with some of the label data.

O'Grady and Magnacca collected the new material for this paper and transcribed the label data and literature records from older material. O'Grady determined the material present in the UC Berkeley collection. O'Grady and Magnacca wrote the paper.