Studies in Hawaiian Diptera I: New Distributional Records for Endemic Asteia (Asteiidae)

Abstract New island records are reported for five species of Asteia endemic to the Hawaiian Islands (Asteia hawaiiensis, Asteia mauiensis, Asteia molokaiensis, Asteia palikuensis, Asteia sabroskyi). These new records expand our understanding of distributions in Asteia, change the percentage of single island endemics from 78% to 33%, and have significance in how we view the process of diversification acting in this lineage. We also present a list of the known rearing records for two species in this group. Asteia montgomeryi has been recorded from Erythrina and Asteia sabroskyi has been reared from Pisonia, Urera, Charpentiera and Hibiscadelphus.

Zimmerman's multivolume Insects of Hawaii series  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).  (Nitta andO'Grady 2008, Goodman andO'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
We have reviewed the literature for the Hawaiian Asteia and have attempted to include infomation on both the taxonomic history of the species and all occurrences of the endemic taxa in the literature, including the original descriptions, subsequent revisions, additional descriptive notes, range expansions and new island records and catalogs. The original authors of most of the species covered here designated holotypes, allotypes and paratypes in the original descriptions. We list the type, paratypes and other material examined. We have attempted to include as much collection data from the original publications as possible. In some cases label data were elaborated via examination of material deposited in the B. P. Bishop Museum or the University of Hawaii Entomological Collection.

Collection Methods
All material was obtained from general sweeping of vegetation, seeps and streams. Samples were preserved in 95% ethanol (ETOH) and transported to UC Berkeley for identification. Key and descriptions by Hardy and Delfinado (1980)