Synonyms
Orcus australasiae var. obscurus Blackburn, 1892: 241.
Orcus obscurus: Blackburn, 1895: 240
Diagnosis
The presence of 3 maculae on each elytron in combination with the relatively small size and tarsal claws with obsolete tooth distinguish this species from the other Australian Orcus.
Description
Length 3.7 mm. Surface dark brownish, each elytron with 3 orange maculae. Head micro reticulate between punctures; punctation almost indistinct, smaller than eye facets, very shallow, nearly 2 diameters apart. Eyes with inner margin slightly diverging apically. Antenna 9-segmented; pedicel about as long as wide; 3rd antennomere slightly shorter than pedicel; 9th broad, slightly longer than basal width. Terminal maxillary palpomere with sides nearly parallel; the apex strongly oblique with outer side about 2 times longer than inner; terminal labial palpomere slightly elongate; about 2 times longer than basal width; visibly shorter than preceding segment. Pronotal surface sculptured as on head; punctation about as large as eye facets, approximately 1.5 to 2 diameters apart; the punctures obsolete on anterior angles; anterior angles without distinct strigae; lateral borders rounded; bordering line uninterrupted at base, the line slightly opening anteriorly, then almost reaching lateral border; prosternum short in front of coxae about as long as prosternal process widest width; hind tibiae with outer tooth; tarsal claws barely widened at base. Elytral surface somewhat coriaceous; punctation similar to pronotum, but difficult to see given the leathery nature of the surface; lateral margin slightly reflexed, without clear bead; epipleural foveae absent. Abdomen with 5 ventrites; 5th rounded at apex; surface of ventrite 1 micro reticulate between postcoxal lines; postcoxal lines joined at middle, weakly recurving apically; apical border of intercoxal process flat.
Male
Male unknown.
Female
Described above.
Variation
Unknown.
Distribution and Biology
Western Australia.
Species References
Blackburn, T. 1892. Further notes on Australian Coleoptera, with descriptions of new genera and species. XII. Transactions of the Royal Society of South Australia, 15: 207-361.
Blackburn, T. 1895. Further notes on Australian Coleoptera, with descriptions of new genera and species. XVIII. Transactions of the Royal Society of South Australia, 19: 201-258.
Slipinski, S.A. 2007. Australian Ladybird Beetles (Coleoptera: Coccinellidae) their biology and classification. ABRS, Canberra. 286 pp.
Slipinski, A. and Giorgi, J.A. 2006. Revision of the Australian Coccinellidae (Coccinellidae). Part 6. Tribe Chilocorini. Annales Zoologici (Warszawa), 56(2): 265-304.
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