Cocoon and Casing

A few days ago David and I discovered a stretch of heathland on Hollesley Common in Suffolk that we had yet to explore. We came across this extraordinary 'sac' on a clump of gorse, and wondered what it might be. It seemed more 'animal' than 'vegetable', so to speak. Had it been made by a spider or a sand-wasp? 

I posted a couple of photos on the iSpot site, and it wasn't long before the mystery was solved ... it's the cocoon of a moth I have been longing to see, the Emperor (Saturnia pavonia). I imagine the second part of its name, pavonia, refers to the peacock-like eye markings on the adult's wing.   

We returned to the spot this afternoon in glorious sunshine. The cocooon was looking rather bleached, but we were able to put David's measuring card alongside it; each black or white square is 1cm, so you can see it is about 3cm in length. 

* * *

I have been fascinated for a couple of years now by the 'Bagworm' and particularly by the casings these Common Sweep  (Psyche casta) moths leave on our brickwork or on our flowers. Usually all I have seen are the casings, but this week I actually saw the larva for the first time, as shown in the two photos immediately below. 

Nature certainly comes in all shapes and sizes!