Biologue

Article by
James S. Ashe, Natural History Museum, University of Kansas, 2385 Irving Hill Road, Lawrence, Kansas, 66044 USA

The rove beetles or Staphylinidae are one of the largest families of beetles, with more than 46,000 species described from throughout the World. The staphylinid subfamily Aleocharinae, the largest subfamily of staphylinids, includes more than 1000 described genera and 12,000 species and is one of the most poorly known of any large group of beetles. The Australian fauna of aleocharine staphylinids, currently consisting of 58 described genera and 201 named species, is currently inaccessible even to the most dedicated specialist because of lack of a modern taxonomic synthesis and identification guide. Most of the current generic assignments were made by the early part of this century (50% before 1895, 80% by 1912, and 90% by 1921). Except for the recent work of David Kistner and his associated on termitophiles, there have been no modern comprehensive revisions and no syntheses.

Aleocharines are abundant, and often dominant, inhabitants of many microhabitats throughout the world, and their abundance and diversity suggest that they have substantial ecological impact. They are among the most abundant generalist predators in most leaf litter and soil communities. Further, various lineages have specialized as inquilines (guests) in ant and termite nests. Representatives of other major lineages are found: in association with mushrooms and fungi, in the intertidal areas of seashores; as "parasites" of Diptera puparia (members of Aleochara); as major pollinators of some palm trees; and as inhabitants of the web-covered burrows of hepialid moth caterpillars (adults and larvae of the genus Tachiona). Many other examples of ecological specialization could be cited. Aleocharines also produce a rich array of chemicals for defense, sexual recognition and other functions.

Some aleocharines are known to have significant agricultural importance. For example, some Aleochara species are of economic importance as natural enemies of noxious flies. Also members of the genus Oligota are known to be important predators on agriculturally important phytophagous mites. Others are of significant abundance and diversity in agricultural situations and are likely to have substantial impact as micropredators. However, because of the lack of identification guides the agricultural importance of aleocharine staphylinids in Australia has not been investigated.

The overall goals of this study are to produce a complete, extensively illustrated guide to the Aleocharinae of Australia with special emphasis on the described and obvious undescribed genera and higher taxa. These guides will be published as both a printed version and a electronic version that takes advantage of the capabilities of available interactive key programmes such as LUCID.

Recent, on-going work in connection with this project allows the following generalizations.

1. The Australian aleocharines fauna is much richer, has more unique higher taxa, and is much more diverse than current knowledge would suggest. This faunal richness is embodied in much more than just an abundance of undescribed species (though this is true as well). There is a great diversity of undescribed genera and higher taxa, that, taken together, constitute a unique and remarkable, and hitherto unexpected, "Australian fauna". Current taxonomic knowledge of the Australian Aleocharinae does not give any indication of the uniqueness, taxonomic diversity and richness of the Australian fauna, and indeed, gives a completely false impression of the pattern of aleocharine diversity in Australia . This unexpected diversity of new higher taxa has led me to adjust my work plan to describe many of the distinctive genera and other higher taxa before completion of a more general identification guide.
2. Some described higher taxa of Australian Aleocharinae are inappropriately applied, heterogeneous in named species assigned to them, and cause much confusion in understanding of the Australian fauna. Of particular importance in this regard are the genera "Calodera" and "Polylobus" (each coincidentally containing 22 described Australian species). Both of these genera, as applied to the Australian fauna, are heterogeneous assemblages of species that actually represent numerous higher taxa (mostly undescribed). I have not seen any Australian aleocharines that can be correctly assigned to Calodera, and most of the species currently assigned to Polylobus are not members of that genus. (The only described species of Polylobus that I have encountered thus far is described as a species of Calodera). These genera will require complete revision before general or accurate conclusions can be formulated about the Australian aleocharine fauna. A similar problem exists, though less dramatically so, for the described Australian species of the genera Atheta, Ocalea and Falagria.
3. The fauna of the aleocharines that live in the nests of termites (called termitophiles) is unusually diverse (23 genera in 10 tribes or subtribes, represented 60 described species), and remarkably well known thanks to the work of David Kistner and his associates.