Slow Spring Progress

Purple Emperor larvae are developing slowly in this cold, late spring (I recorded frosts in my garden on 27 nights during April). 

One larva in Savernake Forest was still on its winter hibernation pad on 30th April, though it had greened up nicely and would have found eadible leaves within half a metre had it bothered to move (oddly, it is in a south-facing position).

Most wild larvae have fed a fair bit, post-hibernation, and will be seeking to change skins into L4 within a few days. This means that they are not that far behind the modern norm. The three I have in captivity (an outdoor sleeve) are all skin changing now, as are one or two early-birds in West Sussex.

Nomally, Emperor larvae are held up by early spring rains - but this time it's cold drought...

I'm not yet able to give a final reading on winter survival / predation percentage, and wont now be able to before mid-May. However, the predation / loss rate is likely to be between 40-50%, which is actually about as good as it gets (last year the winter loss rate in W Sussex was 85%). 

Unfortunately, though, both Ben Greenaway in W Sussex, and me in N Wilts & SW Oxon, seem to have lost some feeding larvae during April, to predation. We may yet refind some of these lost souls, as post-hibernation L3 larvae can at times wander quite far (I've recorded 6m, but 1m is normally plenty). Sadly, at this stage 'Donald', 'Priti' and 'Andrea' (Leadsom) are missing-presumed-crunched. They have a huge following on Twitter.

But 'Boris' and 'Margaret Hilda' are feeding well, and are set to change into the 4th instar very soon (weather permitting). Here's 'Boris' from April 30th:-

The question readers want answering is when will iris start to emerge this year? That's always hard to answer before late May but at this range it's unlikely that the butterfly will start to emerge before June 21st this year - but a warm, dry May could bring that forward.  Watch this space...