These may not look like much – in fact, when looking at these images, you might struggle to see anything but fading flower heads of Yarrow (Achillea millefolium) – but I’ve been checking almost every Yarrow flower I see, looking for these, since I first saw them mentioned on social media a few years ago.

These tiny brown tubes, camouflaged with a plant material covering, are the larval cases of the moth Coleophora argentula. From within their home-made protective covering, the little larvae poke their heads out to munch on the Yarrow flowers and on the seeds when they begin to develop.

According to the British Leafminers website entry on this species, the larvae are usually active from September through to May, so these are a little early; I’m finding many things are early this year, presumably due to the continuing warm weather. You can see the adult moth, a very pretty little thing, with pale brown and white stripes, over on the UK Moths website.

And now, have another look at the first photo. How many of the little brown cases can you find? Answers on a postcard. 🙂