Saturday, 29 December 2012
Not quite in time for Christmas
The grevilleas are full of honeybees and big, fat, flower-eating beetles. I had thought they were Christmas beetles (Anoplognathus) and planned to write a blog post about them for New Year's Eve, there being some vague comic potential in the dodgy timing. (With emphasis on vague and potential. Also dodgy.) But then I examined them more closely. If they were Christmas beetles, they sure were funny lookin' critters.
Christmas beetles are large scarabs (family Scarabaeidae) that emerge — often in great numbers — at the end of the year. Some are beige, some are taupe, others are leaf green or washed with gold. By the end of December, it's not unreasonable to assume that any large, greenish, uncoordinated beetle is an Anoplognathus. And the ones in the grevilleas matched all those criteria.
Mind you, I did wonder what eucalyptus folivores were doing in a grevillea, but...well...it seemed rude to ask.
My beetles are also scarabs, but belong to a different subfamily. Whereas the Christmas beetles are members of the subfamily Rutelinae (leaf chafers), these ones are in the Cetoniinae (flower chafers). Which makes sense, now I come to think of it.
The species is Mycterophallus (or Lomaptera) duboulayi. It is found in Far North Queensland from the Atherton Tablelands to Iron Range. (This distribution is based on data in the Atlas of Living Australia.) I'm not sure if that notch in the clypeus* and/or the 'absence' of the scutellum** are diagnostic for the genus, but those features certainly help to distinguish it from yer common or garden Christmas beetle.
* In front of the mouthparts. The clypeus is quite marked in Anoplognathus.
** The little triangle between the wing cases (elytra) and the pronotum. You can see both the scutellum and the clypeus in this image of Anoplognathus montanus.