Ben Cruachan – natural history

In the previous post I mentioned that autumn was the time for the Hepialids to appear on wet nights, and so it came to pass. On the night of the first wet day this female Rain Moth, Trictena atripalpis was attracted to the light and landed inside the verandah ceiling. She doesn’t have the white wing flashes of the male, just a row of white spots at the end of the wings. The Rain Moth is one of the largest moths that come to my light being approximately 65mm long, I haven’t yet managed to attract a Gum Emperor which would be the largest in this district.

At the other end of the scale is this tiny Oecophorid, 4mm long, and less than a millimetre thick. The photograph is of course greatly magnified and shows the characteristic upturned sickle shaped palps at the front of the head.

One of the most intriguing moth families is the Pterophoridae, or Plume Moths. These small and incredibly fragile moths only appear at the light occasionally, this one has lost part of a wing and a leg. The wing span is about 11 mm. The name of this one is Stenoptilia zophodactylus.

The final moth in this post is a most attractive colour, when it came to the light it landed on my glasses where I first photographed it. I then lost it until I came in for the night and it suddenly appeared, it must have been riding around on my back for half an hour. I took the second photo on the kitchen table before releasing it outside. It’s name is Aglaopus pyrrhata, and the larvae feed on eucalypt foliage. Wingspan is about 28mm. Click all to enlarge.

It will still be some time before I’m fit enough to chase birds in earnest, so for the time being invertebrates are the name of the game. I guess for a lot of people, moths are just something you see in the car headlights or fluttering around an outside light. Until fairly recently that’s pretty much how it was with me too, although I was familiar with the house loving Old Lady Moth when I was a lad on the farm, and I vaguely knew that certain moths that sat flat and camouflaged on various surfaces were called geometer moths. Then thanks to the internet I became interested in knowing more about moths, invested in a mercury vapour lamp, set up a mothing sheet, and became aware of a whole new world out there in the darkness.
Although the most spectacular species are found in the north of the continent, we southerners also have hundreds of beautiful and interesting moths to photograph and endeavour to identify.
Of course it’s not only moths that are attracted to the light, a huge range of other insects arrive and sometimes make mothing impossible due to their sheer numbers and the problems they cause. In summer beetles can arrive in hundreds, covering the sheet and spooking any moth that finds a place to land, the only thing to do then is give the game away and try again another night.
With autumn here it’s time for the Hepialids to leave their underground homes on wet nights, fly, mate, lay their eggs and die, and I sometimes feel a little guilty drawing them into the light instead of letting them get on with their business of organising the next generation. They don’t have much time, just one day, as they have no mouth parts with which to feed, they live just long enough to reproduce.
Quite apart from nuisance insects, some moths are a problem, continually whirling around the light disturbing resting specimens, others zoom in and out with the same result, and others merely observe the goings on from a distance, frustrating the waiting photographer. One that likes to do this is the Eyespot Anthelid, Anthela ocellata, it will often just approach to the outer glow of the light and then settle high in a tree out of range.
Then there are some that cooperate nicely, like the moth in the first photo, Circopetes obtusata. I’ve had it come in more than once, and all have flown in and settled quietly on a verandah post or the brickwork to have their picture taken. It’s quite a large moth with subtle tonings and one that I really like. The larvae of this Geometrid feed on eucalypt foliage, and the common name is Twisted Moth from the way it holds its hind wings bent up. The angle of the body is also characteristic.

The second is a Noctuid and much smaller, the larvae are pests and feed on a variety of plants including tomatoes. It’s a striking little moth for all that, its name is Chrysodeixis eriosoma, or Green Looper.

The larvae of the third moth in this post are beneficial as they feed on weeds like Heliotrope and Paterson’s Curse. It is the Heliotrope Moth or Utetheisa pulchelloides, and is in the Arctiidae family. At times they travel south and appear in our district in very large numbers.

These moths and those to come in another post are all from one night’s mothing. Click all to enlarge.