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Bringing new beetles to light

2012 REU Project:

The beetle family Staphylinidae – the rove beetles – is the largest beetle family in the world, with over 57,000 species and nearly 3,600 genera already described. Several hundred new species and at least two dozen new genera are described every year, the largest proportion of them from Asia.  The faunas of Australia, New Zealand, and southern South America also include many new genera awaiting naming and description but have received less attention.  This relative lack of attention means that even identifying specimens belonging to described genera is difficult, because there are no comprehensive identification guides.  International collaborative work is just beginning on two guides to beetle genera, one focused on Australia and one on southern South America, similar to the two-volume work American Beetles published in 2000 and 2002. Margaret Thayer is a coordinator of the rove beetle chapters of both guides, and hopes to describe the 20 currently known new genera from those areas so they can be included in these guides.  The guides will promote more detailed work on those faunas by any researchers, including describing additional species, synthesizing information on all the species, and analyzing their distributions and evolution. This REU project will involve primarily describing one of the new genera (and, if necessary, new species) belonging to the subfamily Omaliinae, based on existing museum specimens from the collections of The Field Museum and others.  The intern might also help with some aspects of work on other genera.

Research methods and techniques: Research work will include training in beetle skeletal morphology; dissecting, microscopy, and imaging techniques (probably including some SEM – scanning electron microscopy); databasing and georeferencing specimen collecting records; and using the georeferenced records to map the known distribution of one or more species.  The intern will work with the sponsoring curator on writing, for publication, a modern description of the genus with illustrations (drawings, digital macro- and microphotos, SEM) and comparisons to other genera of Omaliinae.  This project will provide experience with museum collections, entomological study techniques, and scientific literature on rove beetles. It may also involve developing and/or testing identification keys, potentially either traditional dichotomous or interactive ones.  Although not directly involving the genus being studied, some local fieldwork would be possible to enable the intern to see other rove beetles in the field.

Curator/Advisor: Dr. Margaret Thayer (Zoology - Insects)

Entomology/Wildlife Conservation double major
University of Delaware

Symposium Presentation Title: Wingless in Tasmania: A New Genus of Flightless Rove Beetle from Tasmania (Coleoptera: Staphylinidae: Omaliinae)

Symposium Presentation Abstract: The family Staphylinidae – the rove beetles – is the largest family of beetles in the world and also one of the least understood. There are currently over 57,000 described species in over 3,600 genera and more are still being discovered at a rapid rate. In this project we describe a new flightless staphylinid genus from Tasmania belonging to the tribe Omaliini of the subfamily Omaliinae, extending knowledge of the highly endemic Australian fauna. We studied the beetles whole as dry specimens and in alcohol as well as cleared and dissected in permanent or temporary microscope slides. Scanning electron microscopy (SEM) allowed us to examine and image selected characters not clearly visible with optical microscopy. Using these sources of data we prepared descriptions and images of the beetles including species-specific genitalic structures and compiled all known distributional and ecological data. We added the genus into an ongoing phylogenetic analysis of World Omaliini by the second author to infer its phylogenetic placement. While we initially believed that this genus consisted of a single undescribed species from Tasmania we discovered that there are actually two species inhabiting different areas of that island. Several other genera of Omaliini have austral disjunct distributions that probably reflect an ancient origin on Gondwana. Our new genus needs to be compared carefully with several undescribed species of wingless Omaliinae known from southern New Zealand to assess whether they are all phylogenetically close – representing another disjunct genus – or convergently wingless.