Back in 2018 (remember those heady, pre-pandemic days) I trapped my first Clifden Nonpareil (Catocala fraxini). It was an amazing moment for me, not least because of its scarcity – at that time a real event and a moth that lots of fellow moth-ers were envious of. I subsequently saw two more that Autumn, while watching my son play hockey in Taunton, where the bright floodlights had attracted them in; and last year I had two more while trapping at Lyme Regis with Paul Butter.
This year though they have been popping up all over the place and moth-Twitter has been alive with reports of this huge moth coming in. Matt had one to his trap a few miles away just a few days ago. The ‘Clifden Club’, as it’s become known, has certainly extended its membership considerably in the last few weeks.
It was therefore not all that surprising to go out to the trap this morning and find a beautiful specimen sitting under the perspex cover.
It’s clear why Blue Underwing is the vernacular name. This one really is a beaut; absolutely pristine condition – which always raises the prospect that it bred nearby rather than flying in from afar. If you’ve not seen this moth before it’s worth noting the scale. I’ve laid it here next to a standard roll of sellotape and you can see that it would barely fit inside the cardboard inner-roll.
This morning was clear after yesterday’s rain, and for the first time I found myself waiting for the morning light and also needing a jacket in air that was quite cold, with a minimum overnight temperature of only 11C. It had resulted in a fairly empty trap therefore, just 38 moths of 19 spp. Crescent Dart, which does well here, was the only other moth of note:
A nice fresh moth, which is more than can be said for this poor old Light Emerald, caught by a spider but too big to fit in the larder!
As I prodded the deceased moth, the spider tried hard to pull it further in, assuming, I guess, that I was after my breakfast too.
Predation, or rather avoiding it, is one of the moth’s most important evolutionary developments. Camouflage plays its part and as Autumn begins to creep in it’s noticeable how the moths of this time of year are adapted. I was struck, for example, by how this Silver Birch leaf, seen in the garden yesterday, would be the perfect daytime hideout for one of this morning’s Canary-shouldered Thorns.
Avoiding predation is the theme of this new academic paper (Neil et al, 2021) which tells of the authors’ incredible recent findings about the evolutionary development of folds in the wings of Silkmoths (Saturniidae). These folds reflect sound is very particular ways, magnifying the calls of bats to give an ultrasound profile which is low near the body and higher at the wingtip. A profile like this acts as a decoy for approaching bats which are more likely to attack the wingtips. Their short Youtube video explains it all and is well worth a watch:
If you’ve trapped moths at all you’ll be familiar with the kind of wing damage they can quite happily sustain and still fly efficiently – as illustrated nicely by one of the Clifden Nonpareils that I caught in 2018, below:
A good morning’s mothing then. Hopefully the warmer nights will return this week to bring more to the trap – but for now I’ve got one large moth that needs releasing back into the garden.
Neil, T. R., Kennedy, E. E., Harris, B. J., & Holderied, M. W. (2021). Wingtip folds and ripples on saturniid moths create decoy echoes against bat biosonar. Current Biology. doi:https://doi.org/10.1016/j.cub.2021.08.038