Followers of the Oxon Wildlife blog may recall I have a colony of Scarlet Tiger moths in my wildlife garden at King’s Copse Park, Garsington that I am more than a little partial to. 2014 was a bumper year for them, with a huge crop of spring larvae being succeeded by literally dozens of adult insects in their flight season. It quite amused me to see the neighbours shutting their windows as these little beauties became most active in the early evenings.
I know very little about moths, and until now have only guessed at my Scarlet Tigers’ life cycle. In past years I have noticed small larvae on the exterior walls of my park home more or less throughout the winter months. In spring much fatter ones mature on the food plants of Comfrey (Symphytum caucasicum) and Brunnera that I cultivated as shade-tolerant ground cover before the trees and hedgerow behind my unit were cleared by the landowner in 2013.
Well something has devastated those original food plants during 2014’s dry late summer, and that malaise has spread to most ground cover plants in my garden through early autumn. “Surely there can’t be so many slugs and snails active in such dry weather, and are they eating the moth eggs?” I wondered. But neither did I notice tell-tale munching caterpillars. Just recently I’ve been finding part-grown Scarlet Tiger larvae on my exterior walls again.
On arriving home this evening I saw that one of my prized pot Abutillon’s had succumbed to the above-noted malaise. And there they were: a crop of part-grown Scarlet Tiger larvae going about their chomping business. Whilst being pleased to see them, I was a little disappointed at their choice of alternative food plant. It was too late for this particular Abutillon in its present season. A scan around the faded autumn garden revealed many more munchers on perennial Geranium, Lady’s Mantle (Alchemilla mollis), Geum rivale, Pulmonaria, Centaurea, Tellima, Hollyhock, and the variegated Brunnera that had survived the initial onslaught. Yike! – though this could save me some work cutting down those various perennials at season’s end.
Cue a web search that turned up an article on the Amateur Entomologists’ Society site. From this it is worth noting that (1) Scarlet Tiger larvae do indeed over-winter but with up to 80 per cent losses; and (2) there have been 43 recorded food plants. I am beginning to fear for my garden in the 2015 season. If there are any moth experts out there who can enlighten me further as to just what I’m letting myself in for, I’ll be pleased to learn more.