Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Thursday, December 11, 2008

Life and Death on a Scribbly Gum

Scribbly Gums in the sandstone country of Kangaloon are an endless source of fascination. So many insects live on these grand trees, and even just between ground level and my head height, one can see so many different insects using the bark as a home, or as a thoroughfare, or, as in this evening's post, as a dining table.

The first insect is a Moth which at first I assumed would be a "Scribbly Gum Moth" one of the moths responsible for leaving the trails in the bark - from which these Gum Trees take their "common name". In fact this Gum is Eucalyptus haemastoma one of a series of smooth-barked Eucaluypts which are attractive to the Scribbly Gum Moths. Many smooth-barked Eucalypts are NOT attractive to these moths. In my former stamping ground of Canberra, the local "Scribbly Gum" is Eucalyptus rossii

Anyway, after having consulted with some Mothy people, it is clear that the true "Scribbly Gum Moth" is much smaller than this. Which leaves me with a blank ID for this moth.
All I know is that it is a day-flying moth, about the size of my fingertip, therefore, I would say it is about 10 - 12 mm in length. With opened wings, I would estimate 15 - 18 mm in wing-span. When it flew, it flew quickly, a short distance and hid again, in near perfect camouflage, on the bark of its beloved tree.

Click on image to see details of head and antennae
The antennae are very long, and folded back along its wings. The palps on the snout of the moth are upturned, with a distinct V shape protrusion. There also appears to be a white, round structure behind the eye, near the front of its wings, but I cannot make anything of it. Its eyes are white.
These two images are of the same moth, in different positions, but similar "stance" each time it landed.

This next insect is "Common Black Robber Fly". As "Robber Flies" go, this one is pretty small. Some have much heavier bodies, and are capable of killing and carrying quite large prey, such as bees, or wasps.
Interestingly, having seen this insect on the trunk of the tree, it re-appeared just a few moments later, with a tiny yellow moth it had just caught. The Fly has landed awkwardly, and is trying to gain its balance, and to secure its grip on the moth.
A matter of moments later, after flying a short distance, and having re-arranged its grip on its prey, the Robber Fly is about to settle down to sucking the life-juices out of the moth.
Click on the image below
to get a good look at the
face of the moth, its eye and antenna.
Life and Death on a Scribbly Gum - in the arms of a Robber Fly.


mick said...

There are so many eucalypts given the common name of 'Scribbly Gum' its rather confusing. Is seems to be a common name across a wide range of areas and different species in each.

Denis Wilson said...

Hi Mick
Yes, you are right about the different species. But obviously there is a some common factor - lets call it "taste". I mentioned two species in the NSW southern regions. Cannot advise about yours.
Still, that point is, these Gums are very attractive to insects. Worth spending 15 minutes crawling around the tree, trying to capture images of them all - ants, flies, wasps, moths, Leaf Hoppers, Cicadas, spiders, etc, etc. Its amazing what you can find. The Chew Family site mentioned on my blog has excellent presentation of Brisbane Insects and Spiders, which should be appropriate to your area.
You'll have to leave the Kayak behind, though!

Boobook said...

Excellent photo essay Denis.

Duncan said...

I've got E. haemastoma in the garden Denis, but nary a scribble, apparently the moth doesn't venture this far south. I've seen plenty of scribbles on E camphora to the north-east, and on snow gums.

Denis Wilson said...

Hi Boobook, Thanks for the compliment.
Hi Duncan, Having grown up in Canberra I have taken it for granted that Scribbly Gum Moths were everywhere. Apparently not! They do go for Snow Gums apparently, but maybe it is the distribution of the Moths, not the host trees which determines the distribution of the scribbles. Thanks for the comment.