Chameleon moth

Large purple moth
Moth from above
Large brown moth
Moth from behind

I have known for a while that the apparent colour of butterflies and (I assumed) moths could change quite dramatically according to viewing angle. My favourite examples of it were the Common Eggfly – (1) and (2) – and its cousin the Blue-banded Eggfly. But then I turned over a board and found this moth – yes, the two pictures show the same moth on the same board under the same lighting.

From above, gorgeously patterned purples, blues and blacks, and from behind, a pleasant but dull red-brown: my new favourite example of the phenomenon.

It’s not really a ‘Chameleon Moth’, by the way. That was just what I called it while I was finding out the correct name (thanks again, Graeme), Speiredonia mutabilis, but the real name does mean something similar – ‘mutabilis’ is, roughly, ‘changeable.’ It doesn’t appear to have a genuine common name.

Orchid – fly – spider

Spray of purple orchids
The flowers

While we’re on spiders, and particularly flower spiders, here’s another – in a setting which neatly demonstrates cause and effect in the food chain.

Our golden orchids flowered a few weeks ago and a purple one followed suit last week. The golden orchids are almost scentless (as far as I’m concerned, anyway) but the purple ones have a strong, sweet perfume which obviously attracts our (in)famous Queensland Fruit Fly, Bactrocera tryoni. There were always a dozen or more of these on the orchid spray, and they came to it last year as well although I don’t usually see them around the garden at all.

A careful look at the orchids revealed another kind of creature on them – flower spiders, there for the fruit flies. The brown one pictured was the bigger of two that I found; the other was the same species as the Flower Spider which caught the wasp, but a smaller individual. Both belong to the same family, Thomisidae, commonly known as ‘Flower Spiders’ and, perhaps mystifyingly, as ‘Crab Spiders’ but I haven’t got a more specific identity for the brown one yet.

Queensland fruit fly on orchid
The fly
Brown and white spider on orchid
The spider
Spider and fly on orchid
Relative sizes

Here’s the Thomisidae family description from Ron Atkinson’s Find-a-spider Guide, which incidentally explains the origin of the common names:

The body is small to moderate in size. The abdomen is somewhat large and more variable in shape than the cephalothorax. The legs are visibly spiny, especially the first two pairs which are very robust and curve forwards in crab-like fashion. The body colour may be white, green or brown to match the colour of the surfaces on which the spider is most likely to be found. The usual habitats are on leaves, in flowers or on/under bark. In the last of these habitats the spider’s surfaces are roughened to improve the camouflage.