Dear Readers, apologies for the preponderance of bracken this week, but reader Danny has reminded me about all the different moths whose larvae feed on the plant, and I think it’s always good to remember that even the most problematic of ‘weeds’ fulfils a role in its native ecosystem. First up is the Garden Tiger moth – the young caterpillars are often found on bracken before they move on to other herbaceous plants. These are the ‘woolly bears’ of my youth, and are still amongst my favourite caterpillars.
Then there’s the Brown Silver-line moth (Petrophora chlorosata), whose caterpillar only feeds on bracken. What an elegant and well-camouflaged moth this is, with its own subtle beauty. The caterpillar has both green and brown forms, with the green form shown below. It seems to be a very energetic little caterpillar, with something of the looper about it. And look at it pictured in situ on a bracken leaf! If I had some bracken nearby I would definitely be keeping an eye open for this chap.
Then there is the Small Angle Shades (Euplexa lucipara). We’re probably all familiar with the Angle Shades moth, but the Small Angle Shades has a rather more out-of-focus/pixellated look about it. You can see them both below so you can make a comparison. The Angle Shades is often found sitting on a wall or fence, minding its own business, so if you’re in the UK you may well have seen one without even being aware of it.
The Small Angle Shades caterpillar is little, fat and green, but it feeds at night so you are unlikely to see it unless you’re rooting about in the bracken with your head torch on. It also feeds on other ferns and a wide variety of herbaceous plants.
And then there are the Swift moths. There is the Orange Swift…
the Common Swift moth…
and the Gold Swift
However, what you’re unlikely to see are the caterpillars of these moths, as they all live underground, munching on those eagle/oak-patterned roots for up to two years before appearing as a moth. Sadly they may also munch on other plants, including your prized paeonies or Michaelmas daisies, and so may be seen as a garden pest. I rather think that the adult moths are worth waiting for, though, especially if the caterpillars are only eating bracken. The adults have non-functioning moth parts, so they are only interested in reproduction rather than eating.
So, bracken may be a bit of a thug in the wrong place, but look at all the wildlife that it supports! I shall certainly be looking at it with more affection next time I fight my way through a thicket of it.
Photo One by Temple of Mara, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons
Photo Two by Dean Morley at https://www.flickr.com/photos/33465428@N02/5583264398
Photo Three by Ben Sale from UK, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons
Photo Four by David G Green from https://www.hantsmoths.org.uk/species/1902.php
Photo Five by By © entomartIn case of publication or commercial use, Entomart wishes then to be warned (http://www.entomart.be/contact.html), but this without obligation. Thank you., Attribution, https://commons.wikimedia.org/w/index.php?curid=1253796
Photo Six by Rob Mitchell, CC0, via Wikimedia Commons
Photo Seven by Line Sabroe from Denmark, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons
Photo Eight by Ben Sale from UK, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons
Photo Nine by Ben Sale from UK, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons
Photo Ten by Chris Cant from Cumbria, UK, CC BY 2.0 <https://creativecommons.org/licenses/by/2.0>, via Wikimedia Commons
Photo Eleven by Bernard Ruelle from https://butterfly-conservation.org/moths/gold-swift
Photo Twelve from https://www.rhs.org.uk/biodiversity/swift-moth-caterpillars