Methods and standards

We maintained several standards in the development of this tool. Terminology, diagrams, and morphological terms used in the diagnoses and keys can be found in the glossary.

What measurement standards did you use? For body length, we measured from the apex of the clypeus to the apex of the pygidium.

How do you define “horns”? Head armature includes horns, tubercles, protuberances, or ridges that are located on the dorsal surface of the clypeus or frons. Pronotal (thoracic) armature includes horns, humps, pegs, tubercles, protuberances, or ridges that are located on the dorsal surface of the thorax.

Did you voucher any specimens? Many insect collections were examined as part of this research. Specimens were authoritatively identified, databased, and vouchered in entomology collections (specimens retain a “Hawaiian Scarabs” voucher label). Specimen vouchers allow this research to be repeatable.

Did you examine type specimens? To untangle valid species names for some species, type specimens (Ataenius pacificus, Ataenius liogaster, Ataenius nocturnus, Ataenius yasamatsui, Ataenius vandykei, Diasticus hawaiiensis, Holotrichia bipunctata, H. mindanaoana, Microserica guamensis) were borrowed from several museum collections.

What scientific classification did you use? Scarabaeoid taxonomy and classification follows catalogs by Krajcik (Scarabaeoidea, Cetoniinae, Rutelinae, Scarabaeinae) (Krajcik, 1998; Krajcik, 1999; Krajcik, 2006; Krajcik, 2008; Krajcik, 2012), Gordon and Skelley (Aphodiinae) (Gordon and Skelley, 2007), Zidek (Trogidae) (Zidek, 2013), and Hawks (Lucanidae) (Paulsen and Hawks, 2014).

How were distributions determined for each species? An important source for the scarab distribution maps was the "Hawaiian Terrestrial Arthropod Checklist" (Nishida, 2002). This list provided information regarding species that are established in the state, but does not provide specific information regarding which islands species are "established" versus "recorded but not established". There is a general paucity of such information available, particularly for commercially unimportant species. As such, all islands where an established species has been recorded are shown as "established" on the distribution maps for this tool.

Why did you include common names? To assist in accessibility of this tool, we included common names of scarab beetles. Unlike scientific names, however, common names are not unique. For example, the “oriental beetle” may have been used to refer to several species of scarab beetles such as Popillia japonica, Anomala orientalis, and Protaetia orientalis. Additionally, unlike the scientific name, common names can differ regionally. For example, the coconut rhinoceros beetle goes by the common names of “bhowara”, “mobar”, “munga”, “schalu doombi”, and “pálai vundu” in India; “gascooroominga” in Sri Lanka; “rhinoceros du cocotier” in France; “kumbang tanduk” or “kumbang badak” in Indonesia; “klappertor” in the Netherlands; and “Indischer nashornkaefer” in Germany (CABI 2015). The ultimate arbiter for scientific purposes is the unique, scientific name. We use the standardized Common Names of Insects and Related Organisms provided by the Entomological Society of America. So, for example, within this tool, the “oriental beetle” refers to Anomala orientalis. When not available, common names were based on community usage.

How did you develop images for this tool? Images were taken with a Leica IC80 HD digital camera and processed using the Leica Application Suite version 4.0.1. Images were modified (background whitened, pins removed) using Photoshop CS 4 v. 11.0.2.