Monthly Archives: December 2011

Monster Moth – Helena Emperor Moth

Opodiphthera helena

Jess spotted this huge moth on the rock ledge out the back one evening. It was just sitting there slowly beating it’s wings. It didn’t look injured, I wondered if it had recently emerged from it cocoon and was drying or stretching it’s wings.

Check out the match stick for some scale, it’s body was just monstrous.

I’ve been trying to work out what species this is. CSIRO’s what bug it that site looks comprehensive, but it is soooo slooow it’s excruciating. I’d usually click about quickly and explore but it takes over a full minute for a page to load, the site is unusable.

Google has a fantastic new image search feature where you can give it a picture and have it return similar pictures from all over the web. To use it go to Google Image Search, and drag a picture onto the search box. I tried it out with one of the moth pictures, it returned a bunch of images of similar colour and shape, but none of them were moths 🙁 You can also type in a search word next to the picture, I tried “moth”, bingo! The pictures that came back were of somthing called the Polyphemus Moth. It looked close but not quite the same, a quick lookup on Wikipedia showed it was only found in Central and North America, damn. The article also said it’s a member of the Saturniidae family.

Now that I had an idea what to look for I went back to the CSIRO site and found a link to a Saturniidae page! The pictures there still weren’t a great match though. A narrower search on Google for “saturniidae australia” brought up some much more promising links. The closest I’ve found is Opodiphthera helena, commonly called the “Helena Gum Moth” or the “Helena Emperor Moth”

It matches on looks and location. I think this is it! Woohoo, the Internet does it again!

Helena Emperor Moth
This is one monster moth, check the size of it's body.
Helena Emperor Moth
Helena Emperor Moth. It was sitting there calmly beating it's wings.

More Info:

Trigger Plant

Stylidium productum

“A tufted herb with grass like leaves, found in moist forest situations.”NPOS p.219

The trigger plant has developed the fascinating ability for movement fast enough to outdo animal reflexes. The trigger plant’s pollen producing anthers are located at the end of a stalk emanating from the center of the flower. The stalk is cocked back behind the flower like the hammer of a gun. When an insect lands it triggers the hammer which crashes onto the insect, showering it with pollen. The insect then flies away to fertilize the next trigger flower it lands upon. The flower resets itself in 20 minutes, ready for it’s next customer.

There are several species of trigger plant found in the Sydney area, I’m reasonably confident this is the Stylidium productum. It was found on a moist hill side atop Hawksburry sandstone. Stylidium productum is a small herb like plant consisting of a single stem, leaves are grass like and grow directly off the stem. Flowers grow at the end of a stalk that comes out of the top of the plant. We’ve got a few of these in the yard but they usually get munched by rabbits or wallabies before they get a chance to flower.

Trigger Plant
Leaves of the trigger plant. The long flower tipped stalk grows out from the top of the plant.
Trigger Plant flowers
The purple flowers of the Trigger Plant. Each flower has a hammer cocked and waiting to be triggered by the next insect that lands on it.
Trigger Plant Flower
Trigger Plant Flower locked and loaded. The arrow traces the arc of the hammer.