Delay!

   The current cool weather has slowed larval, and doubtless pupal, development right down. This means that the flight season may well not start before mid-June now (and the weather may worsen over the Jubilee weekend, given the track record of jubilee weather...). 

  The three larvae I have in a sleeve in my garden have virtually stopped developing altogether, but we've had night temperatures as low as 1C (on the last two nights)! They're full grown, or thereabouts, but need warmth to start to pale up and begin the process of pupation.

  Likewise, the larvae I'm following in my local woods (Boris & Co) have slowed right down, with the exception of Priti and Liz who are late developers, now catching up.

  My guess is that some larvae pupated in the Southeast over the warm weekend of May 21st-22nd, possibly one or two before then. In theory those could start to emerge as butterflies circa June 10th, but they're very few of them and may not get seen. We could be in for a longer than normal flight season. And there could be a goodly number of aberrations around, due to cold nights producing cold shock on newly formed pupae. 

  Cool weather slows pupal development right down, and we know that the longer the insect stays in the pupal stage the fewer adults fly, due to increased mortality. The future of the 2022 Purple Emperor season hangs in the balance.

Watch this space...

Here's Jacob from May 29th -

Stuck on his seat leaf waiting for it to warm up...