Sunday, June 8, 2014

2014 Purple Emperor Season: Prospects

There's been a report of a 'probable Purple Emperor', from Sheepleas on the Surrey Downs, today (Sun June 8th).  That would be the earliest the butterfly has been seen nationally since the great summer of 1893...

I doubt the butterfly will appear anywhere before June 18th - but all things are possible with this the best of all possible butterflies, and it may just be that the odd larva got way ahead of schedule in sunny Surrey before the weather capitulated in late May.  Certainly, the forecast for this next week is good and camilla, the White Admiral is starting - and iris appears when camilla is nicely out.

My belief is that iris is very much in this stage -

and it tends to last 18+ days in the pupal stage (in very hot weather the pupal stage may last 14-15 days).

As already stated on this Blog, I am not anticipating a large emergence this year, but a) I'd be delighted to be wrong and b) much depends on flight season weather.  This belief is based on the fate of nearly 100 larvae I followed in / around Savernake Forest in Wiltshire.  Losses during the autumn were at normal level, but then losses to predation during the winter were by far the highest I've recorded (from a sample of 63 hibernating larvae this winter), and losses to assumed predation continued at an alarming and unprecedentedly high rate in spring.  But, that's just a single monitored site, and loss levels may have been lower elsewhere - we simply don't know. 

Whatever, there is no such thing as a bad Purple Emperor season.  Other butterflies, mere ephemera, experience poor seasons: He does not. Watch this space...

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