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Passalid Beetle

Pharochilus dilatatus


Shining, black, somewhat flattened beetles, with prognathous head, sometimes horned, characteristically curved antennae, and narrow pedicel or waist between prothorax and elytra. Scutellum not visible; elytra conspicuously striate. This specimen was approx. 30-35mm in length (from memory).


Found on Tamborine Mountain, SEQ. Heavily wooded area, sub-tropical rainforest, lots of undergrowth (logs, leaves, branches, etc.) This one was found on a wooden pool deck, and there are many rotting posts along its fence. Also lots of leaf litter and rotting logs from native eucalypts. Other species of Pharochilus prefer drier habitats, whilst others go even further up mountains (like Lamington, for example).


The identification of this beetle was done by the Queensland Museum. They sent a detailed response to my written request for correct ID. Also, the mite on the beetle in photograph #5 of this series is a member of the Fedrizziidae, a family found only on Passalid Beetles. NB: The Black Bess Beetle (Mastachilus sp.), even though of the same Family (Passalidae) as the Passalid Beetle, is slightly different in that it has a crease on the thorax, and also a small curves horn. Passalid doesn't.

1 Species ID Suggestions

Black Bess Beetle
Mastachilus sp. Black Bess Beetle - Mastachilus sp.

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Mark Ridgway
Mark Ridgway 8 years ago

Wow seriously good ID work.

fishnlove 8 years ago

I've caught a lot of these they almost all seem to have those mites on them. We just call them wood beetles

naross 8 years ago

I'm not too sure about the Black Bess ID simply because it has the defined crease on the thorax, and also has a small horn. This beetle doesn't. Other than that, they look so similar. Perhaps the male and female of the species ave these differences. This link shows the BB top and profile view.

naross 8 years ago

Yeah, he's got a rough head! His mum loves him though. Perhaps this one as well for the Queensland Museum? They'll designate me as a pest!

Mark Ridgway
Mark Ridgway 8 years ago

Wow what a head !! Like melted plastic.

Leuba Ridgway
Leuba Ridgway 8 years ago

very nice, Neil ! Looks like he's got a tiny mite on his back. That's good information highlighting all the differences - will help me watch out.

Neil Ross
Spotted by
Neil Ross

Queensland, Australia

Spotted on Oct 16, 2011
Submitted on May 13, 2013

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