Proxys sp. | Barão Geraldo, Campinas, Brazil
Another stink bug (family Pentatomidae) from my recent travels to South America, but this one from southeastern Brazil rather than Argentina. Although the white spot at the apex of the scutellum is a common theme across the family, the jet black coloration and strongly acute clypeus (“nose”) immediately reminded me of Proxys punctulatus from eastern North America. Although that species does also occur south through Mexico and Central America into northern South America, the lack of distinctively black femoral apices (“knees”) on this individual suggest it is likely a different species. I’ve not found much information on other species in this genus, as my old standby Flickr repeatedly proffers images of P. punctulatus in its Pentatomidae pages but not other species in the genus. Grazla and Campos (2010) list P. hastator from “Cayenna” (likely French Guiana) and P. victor from “Brésil,” and an illustration of the latter in the monumental Biologia Centrali-Americana (Distant 1880-1893) agrees reasonably well (but not completely) with this individual. For now, this will have to stand as Proxys sp.
REFERENCES:
Distant, W. L. 1880-1893. Biologica Centrali-Americana. Insecta. Rhynchota. Hemiptera-Heteroptera. Volume I. London: published for the editors by R. H. Porter, 462 pp.
Grazia, J. and L. A. Campos. 2010. Neotropical Pentatomidae (Insecta: Hemiptera: Heteroptera) of the collection of Massimiliano Spinola preserved in the “Museo Regionale de Scienze Naturali”, Turin, Italy. ZOOLOGIA 27(3):413–424.
Copyright © Ted C. MacRae 2011
Beetles In The Bush 
I can’t quite interpret the wierdness at its tail-end. Parameres and a heck of an aedeagus? (Do Hemiptera even have parameres?)
As far as I can tell, male pentatomoid genitalia are enclosed in a structure called the “pygophore” – I presume that is what is extending beyond the elytral apices, with the tips of the parameres just visible at its caudal edge. Females have a ventrally-situated genitalic orifice surrounded by small gonocoxal plates.
Shoulder pads must be coming back into fashion.
In the past I have seen some Neotropical stinkers with quite impressively projecting shoulder spines. There are some pretty cool hemips the more I look at them.
Does this bug reside in Perth, Australia??
This species is South American, but the family that it belongs to contains thousands of species all over the world. Australia has many species—here is a snapshot of some of them: http://bie.ala.org.au/species/PENTATOMIDAE+(Animalia)