Christmas Bells

Christmas Bells
Christmas Bells - Blandfordia nobilis

Friday, May 25, 2012

Swarms of Swift Moths - on a wet night

On Thursday evening it had been raining in Robertson, and I had been away in Wollongong. When I returned I found my front verandah festooned with Swift Moths.
Swift Moths waiting for me to let them inside
Oxycanus dirempta

Even more Swift Moths on my screen door.
Oxycanus dirempta
I took a few images, and then came inside.
I opened my Computer and found an email from Martin Butterfield to say that he had "several hundred Swift Moths at our place tonight" (Martin is at Carwoola, NSW - somewhere in that district anyway, I believe).

My point is that my experience is not confined to Robertson. Cold weather and moderate rainfall (confirmed by this map) do seem to bring these Swift Moths out.

I have certainly noted their appearance being linked to wet nights previously - co-incidentally it was in the same season, (on 21 May - albeit in a previous year).
A mottled pattern on the wings of this one
Oxycanus dirempta

Strong silver lines on this Swift Moth
Oxycanus dirempta

A combined mottled pattern and vertical lines
Oxycanus dirempta.
Two contrasting wing patterns
on some of the Swift Moths.
Oxycanus dirempta

Several years ago I sent images to Donald Hobern who was at that stage in CSIRO, Canberra, at the Australian National Insect Collection.
Donald told me: "Just checked in ANIC. Based on the specimens there, Oxycanus australis is relatively consistent in appearance (like the image I forwarded earlier), whereas O. dirempta covers the diversity of all your photos - including some exceptionally close to the most highly patterned ones you show. I would therefore say that the likely identification is O. dirempta."


Flabmeister said...


Excellent post: I have put a bit on my blog! The frogmouths are looking fat and contented in the favourite perch this morning.

When are the dalek eggs going to be explained?


Flabmeister said...

Ignore second, smartypants, comment. I should have checked first!


Ian said...

No shortage of subjects and lots of pattern variations, how good is that.

Wally said...

Ah, so that's what flew into our window the other night. My son called me to come and have a look, it was a big one and he was puzzled as it isn't the right time for bogongs, I didn't know what to make of it.

Sue Catmint said...

butterflies are such showoffs compared to the subtle markings of moths such as these. The id thing is certainly fraught - I'm afraid I'm a bit gung ho - I just jump in, choose the closest one I can find and hope that it's right or that i'll be corrected.

Denis Wilson said...

Thanks Ian, Catmint, and Mac.
Yes, it was a good night for the Swift Moths.
There was certainly great variety, but apparently this does not mean different species (so the experts tell me).
Strange how I can have so many moths one night, and none the next.
The like rainy nights (to come out on).
And appear to dislike strong windy nights.