Australian Biological Resources Study

Australian Faunal Directory

<I>Omorgus australasiae</I> (Erichson 1842)

Omorgus australasiae (Erichson 1842)


Regional Maps


Compiler and date details

1 December 2002 - Gerasimos Cassis & Tom A. Weir


The Trogidae are a cosmopolitan family, comprising three genera and about 325 species. Scholtz (1986b) excluded the genera Glaresis Erichson, Afroglaresis Petrovitz, and Cryptogenius Westwood from the family, leaving three recognised genera, Trox Fabricus, Omorgus Erichson and Polynoncus Burmeister. Scholtz (1982) catalogued the Trogidae of the world. The Trogidae are now considered to be most closely related to the Hybosoridae and Ceratocanthidae (Howden 1982; Scholtz 1986b). Strümpher et al. (2014) analysed the phylogeny of the family, based on mitachondrial and nuclear ribosomal DNA sequence data.

The genus Trox is found in the Holarctic and Afrotropical Regions and is represented in Australia by the introduced species, Trox (Trox) scaber (Linnaeus). The remainder of the Australian fauna, comprising 52 species, are assigned to the genus Omorgus (Omorgus) which is known also from the southern Nearctic and Neotropical Regions. Macleay (1864, 1871, 1888) and Blackburn (1892, 1895, 1896, 1904) described a number of the trogid species and Haaf (1954, 1957, 1958) revised the Australian fauna and added 11 new species. Scholtz (1986a) monographed the Australian fauna, recognised new synonymies and described ten new species. He placed all Australian species, except for Trox scaber, in Trox (Omorgus), but later elevated Omorgus to generic status (Scholtz 1986b). Barbero & Palestrini (2003) gave new records for eight species of Omorgus.

The biology of this family is characterised by keratinophagy, with the larvae and adults of most species being facultative necrophages. They have been taken from a wide variety of animal remains, such as carcasses, skin, carnivore faeces, regurgitates of predatory birds, locust eggs and fly maggots. The adults are usually among the last of the succession of insects to invade carcasses. Eggs are laid in the soil beneath carcasses under which the larvae form vertical burrows. Some species are also known from the nests of birds and mammals (Lawrence 1982). Leefmans (1932) recorded Omorgus (Omorgus) costatus (Wiedemann) feeding on bat guano in caves in Sulawesi; this behaviour is suspected for two other Australian species, O. brucki (Harold), O. alatus (Macleay), and the Oriental species O. mollis (Arrow). Wing polymorphism is common in the Australian trogids, e.g. O. tatei (Blackburn) and O. gigas (Harold) are micropterous while O. aphanocephalus (Scholtz) and O. ovalis (Haaf) are brachypterous. The alate species are attracted to light at night. Trogids are well adapted to arid regions and are common in the interior regions of Australia.



The Trogidae or carcass beetles are medium to large-sized (7–20 mm) and are heavily sclerotized, with embossed or tuberculate sculpture (Moore 1986). They are moderately to strongly convex, dull in colour, and usually glabrous. The head is deflexed, the antennae are 10-segmented, the mesocoxal cavities are broadly closed, and the abdomen is entirely covered by the elytra. The larvae have 3-segmented antennae, a bilobed labrum, a darkly pigmented head, and abdominal terga with transverse folds and short spines (Lawrence 1982). Scholtz (1991) described the larvae of some Australian Omorgus species and discussed implications for the phylogeny of the family.


General References

Barbero, E. & Palestrini, V. 2003. Coleoptera Trogidae, Geotrupidae, Hybosoridae, Scarabaeidae (Scarabaeinae and Dynastinae) collected in Australia. pp. 303-328 in Daccordi, M. & Giachino, P.M. (eds). Results of the Zoological Missions to Australia of the Regional Museum of Natural Sciences of Turin, Italy. I. Monografie del Museo Regionale di Scienze Naturali, Torino, 35, 565 pp.

Blackburn, T. 1892. Further notes on Australian Coleoptera with descriptions of new genera and species. Part XI. Transactions of the Royal Society of South Australia 15(1): 20-73 [Date published July 1892]

Blackburn, T. 1895. Further notes on Australian Coleoptera with descriptions of new genera and species. Part XVII. Transactions of the Royal Society of South Australia 19: 27-60 [Date published Jul., 1895]

Blackburn, T. 1896. Coleoptera (exclusive of the Carabidae). pp. 254-308 in Spencer, B. (ed.). Report on the work of the Horn Scientific Expedition to Central Australia. Part ii. Zoology. London : Dulau iv 431 pp.

Blackburn, T. 1904. Revision of the Australian Aphodiides, and descriptions of three new species allied to them. Proceedings of the Royal Society of Victoria 17: 145-181

Haaf, E. 1954. Die australischen Arten der Gattung Trox (Col. Scarab.). Entomologischen Arbeiten aus dem Museum Georg Frey 5: 691-740

Haaf, E. 1957. Drei neue Trox-Arten (Col. Scarab.). Entomologischen Arbeiten aus dem Museum Georg Frey 8: 692-695

Haaf, E. 1958. Nachtrag zur Revision der australischen Arten der Gattung Trox (Col. Scarab.). Entomologischen Arbeiten aus dem Museum Georg Frey 9: 1078-1082

Howden, H.F. 1982. Larval and adult characters of Frickius Germain, its relationship to the Geotrupini, and a phylogeny of some major taxa in the Scarabaeoidea (Insecta: Coleoptera). Canadian Journal of Zoology 60: 2713-2724

Lawrence, J.F. 1982. Coleoptera. pp. 482-553 in Parker, S.P. (ed.). Synopsis and Classification of Living Organisms. New York : McGraw Hill Vol. 2 vii 1232 pp.

Leefmans, S. 1932. Biologische gegevens van een in grotten levenden Trox uit Zuid-Celebes (Trox costatus Wied.) Lammellicornia, Scarabaeidae, Trogini. Tijdschrift voor Entomologie 75: 36-43

Macleay, W.J. 1864. Descriptions of new genera and species of Coleoptera from Port Denison. Transactions of the Entomological Society of New South Wales 1: 106-130, pl. IX

Macleay, W.J. 1871. Notes on a collection of insects from Gayndah. Transactions of the Entomological Society of New South Wales 2: 79-205

Macleay, W.J. 1888. The insects of King's Sound and its vicinity. Part II. The Lamellicornes. Proceedings of the Linnean Society of New South Wales 2 3: 897-924

Moore, B.P. 1986. A Guide to the Beetles of South-Eastern Australia. Greenwich : Australian Entomological Press Vol. Fasc. 7 pp. 101-116.

Scholtz, C.H. 1982. Catalogue of world Trogidae (Coleoptera: Scarabaeoidea). Department of Agriculture and Fisheries, Republic of South Africa, Entomology Memoir 1982(54): 1-27

Scholtz, C.H. 1986a. Revision of the genus Trox Fabricius (Coleoptera: Trogidae) of the Australasian Region. Australian Journal of Zoology Supplementary Series 125: 1-99

Scholtz, C.H. 1986b. Phylogeny and systematics of the Trogidae (Coleoptera: Scarabaeoidea). Systematic Entomology 11: 355-363

Scholtz, C.H. 1991. Descriptions of larvae of Australian Omorgus Erichson, with implications for the phylogeny of the Trogidae (Insecta: Coleoptera). Invertebrate Taxonomy 5(4): 827-835 [Date published 18/Oct/1991]

Strumpher, W.P., Sole, C.L., Villet, M.H. & Scholtz, C.H. 2014. Phylogeny of the family Trogidae (Coleoptera: Scarabaeoidea) inferred from mitochondrial and nuclear ribosomal DNA sequence data. Systematic Entomology 39: 548-562


History of changes

Note that this list may be incomplete for dates prior to September 2013.
Published As part of group Action Date Action Type Compiler(s)
12-Feb-2014 TROGIDAE 07-Jul-2014 MODIFIED Dr Federica Turco (QM)
12-Feb-2010 (import)