Friday, May 24, 2024

Mid-June Kick Off

The prospects for a record-breaking early Purple Emperor season have faded, due to indifferent May weather. Moreover, the outlook for the next two weeks isn't hot and dry, though it is better for the Southeast, where the Emperor season invariably begins.

Emperor larvae are currently starting to pupate (a few may have already done so in Sussex, Surrey and Kent), but the pupation and pupal processes this year are likely to be drawn out by relatively low temperatures and spells of rain.

At this range, we are on for a mid-June start in Sussex and Surrey, though an earlier start remains possible.

Some midsummer species are, though, still on for very early flight seasons, having jumped the gun in early spring (notably White-letter Hairstreak but probably also some of the Browns.

Here's my captive PE larva, 'Mr Tumnus' - only it looks like he's successfully transitioned to 'Miss Tumnus'...

Coming soon: Visiting Knepp in '24 


Wednesday, May 15, 2024

The 2024 Purple Emperor Season...

Since my last post, in mid-April, Emperor larvae have been slowed down by adverse weather: a 12-day cold spell in late April, and then the wet start to May. Sadly, then, He should not be on the wing in May this year... 

One larva I've been following closely spent nine days skin changing to L4 (4th instar) in late April, but then only three days changing to L5 (5th & final instar) during the warm second week of May. 

That one is, though, is a late developer. This spring, we may well have had some final instar larvae in April, in the warm Sussex / Surrey region. 

As things stand, the 2024 Purple Emperor season is likely to start during the second week of June, probably around the 10th (Sussex, Surrey). 

But that is weather dependent - a hot second half of May and a fine start to June could yet see 2024 establish a new record for the earliest UK PE (currently, the date of the official all-time earliest definite PE is 10/6/1893, followed closely by 11/6/2011 and 11/6/2017).  

Conversely, if the second half of May is grotty, and June starts poorly, PEs may not begin before mid-June. They can get stuck for ages pupating, and then get stuck in the pupal stage during cool or wet weather... 

Watch This Space, an early Emperor season is still on the cards. I will tip you off when it's time. Whatever, do not plan on going Emperoring after July 21st this year, they'll be gone.

Finally, we run an inner sanctum of Emperor research workers on WhatsApp (the People of Purple Persuasion WhatsApp group, 55 members). Do please email me if you want to join (though we are not a photographers group, and are fairly extreme - several of us only work the larvae! Email  We particularly need someone from Kent...