Butterfly of the Year 2025

Though it will come as no surprise, we are delighted to announce that the Purple Emperor Apatura iris L. has won Butterfly of the Year 2025, stormed it in fact.

Commiserations to the likes of the Large White, Comma, Peacock and Brown Argus, Common Blue and Small Copper, who might have won had the Emperor been less wondrous.  

Here's an unusually dark-form larva in a twig fork in a veteran sallow in Savernake Forest, Wiltshire, signing the old year off -

2026 is of course the 50th anniversary of the Long Hot Summer of 1976. Make no mistake, it's coming back...

 

Mid-December News

Purple Emperor larvae are now all in hibernation. The last lingerers went into hibernation at the start of December - very (and possibly unprecedentedly) late...

Some larvae changed position during mild weather in early December, mainly from buds to forks or scars.  

The sallow leaves are all off too. It looked as though many sallows were going to retain leaves well into December, but there was a mass sallow leaf fall during the month's second week.  

This means that the Dangle Leaf season is effectively over, apart from in sheltered stream gullies and on sallows along the edges of thicket-stage conifer blocks. 

Provisional analysis suggests that relatively few larvae are hibernating by buds this winter, and that forks and twig scars are being favoured, like these two (Savernake, 14th December) -

This is odd.

Titmouse numbers seem ominously high in the Emperor woods this winter, following a successful breeding season in the fine spring weather. Great Tit, in particular, is a major predator of hibernating Emperor larvae. I have already heard my first Great Tit of next year singing (Dec 14th)!

The Purple Emperor has, of course, won Butterfly of the Year 2025, by a very long way. The issue is who has come second and third?

 

 

Lingering Late...

Purple Emperor larvae are lingering late this autumn, as are the sallow leaves. 

This photo was taken in Savernake Forest on Sunday November 30th. It shows a larva still in its October resting position on a leaf tip -

This is the UK's latest recorded observation of a PE larva still on a feeding leaf and not either in hibernation or crawling off to hibernation. 

Incredibly, this larva was feeding here into early November. It is  unprecedented for larvae to be feeding in November (I observed three larvae feeding at the start of November this year). 

Also, a number of larvae have recently changed hibernation position, mainly from buds to forks or twig scars. This happens in mild autumns, usually when larvae feel over-exposed.  

Here's one neatly hidden in a twig scar, taken on Nov 30th - 

And here's one by a bud, again photoed on Nov 30th (note the green sallow leaf background) -

This was a very mild (if wet) autumn, with the first frosts not arriving in The Empire until the night of Nov 17-18th. Many sallows have stayed decidedly green, like this one photoed in NW Wiltshire on Nov 27th -

Some sallows may still be in green leaf at Christmas! Or even perhaps at New Year...

This has impacted on the Dangle Leaf season. In particular, many feeding leaves used in October are still attached by the petiole, meaning that they are not dangling prominently on silk strands. They may or may not dangle now, but there's a chance that some new dangles may yet appear, perhaps as late as Christmas. Much depends on the weather...