Thursday, 2 October 2008

Mimicry in Longicorn Beetles

.....Macrones sp. and an unknown

I spotted an interesting insect while up the backyard today. It had me fooled for a moment. I initially thought it was a scorpion fly until I looked closer. It seems it is actually a Longicorn beetle, Macrones sp, from the family Cerambycidae. It was around 25mm in length. In the photograph you might notice it is on a Blackwood sapling but it crawled it's way into a flowering Spike Beardheath, Leucopogon australis, no doubt looking for a feed. The adults of these beetles feed on nectar while the larvae are borers in Eucalytus trees. Apparently the Genus Macrones are considered wasp mimicks. As mentioned above I actually thought it was a Scorpion fly but I'm sure it doesn't care what I think as long as the birds reckon it's a wasp :-)

My attention was then diverted by an ant, about 7-8mm in length, crawling up a stem which I was holding away from the camera. Not wanting to be bitten I decided to photograph the ant instead. I took several photos of it side on. Then when it turned on a different angle, I realised it wasn't an ant at all but another Longicorn beetle. Unfortunately the lateral shots did not turn out which is a shame. I've included a blurry shot anyhow just to show how "ant like" it was. The third and fourth photo below shows this beetle.

While watching this one through the lens it came face to face with the original beetle. A wasp mimick meets an ant mimick - You have to wonder if they recognise themselves as beetles :-) Both seemed a little startled but the larger beetle (Macrones sp.) dropped from the branch into the undergrowth.

(Click on Photos to Enlarge)

Macrones sp.

Macrones sp.

Unknown Longicorn beetle - Pos. Ochrya coarctata - about 8mm.(excluding antennae)

Unknown Longicorn beetle - Blurry but you may see how it resembles an ant.

Source of nectar - Leucopogon australis - Spike Beardheath


  1. Beetles rule, OK!

    Haldane would have said that had he lived in our sound bite world. Wouldn't he?

  2. Quite a few longicorns coming into the moth light, nothing as interesting as yours though Mosura. Interesting.

  3. Thanks Tony - Well there are certainly enough of them as Haldane indeed acknowledges.

    Thanks Duncan - No beetles in my moth trap lately. No moths either :-)

  4. Nice ones Mosura. Something fascinating about the mini world isn't there? It's going on all around us all the time, and mostly we don't take the time to see it.

  5. What a weird longicorn.

    As I've said before, so much to learn ...

  6. Thanks Gouldiae and Snail - Yes it's the never ending variety that keeps me interested.

  7. Cool mimics. We have a few wasp (Necydalis) and ant (Euderces) mimicking cerambycids in North America also.
    regards -- ted

  8. Thanks Ted - for popping in. That's a great beetle blog you have there.