The Northern situation

Records from a  number of new localities were received, reflecting the good season all over the country.

Derbyshire

Three new sites in the south, and five new sites in the north-east. The latter are particularly interesting: all with about 10 miles of each other; probably due to expansion from Sherwood forest: a few miles to the east.

Nottinghamshire

Two new localities. The existing habitats: Sherwood Forest, Cotgrave Wood, and Wellow Wood had higher numbers than usual.

Leicestershire

This is the best of the northern counties, with colonies in 11 localities, most within the National Forest area. Three new new habitats were discovered, the most notable being the Queen Elisabeth diamond jubilee wood.

Lincolnshire

Chambers Farm Wood is the best locality in this county, and 2025 was no exception, with the earliest sighting ever recorded here: June 18th. The species is spreading to the other neighbouring Bardney Limewoods: in psarticular, four were seen in a wood near Wragby. 

The Emperor has existed in some of the woods in the south of the county for a long time. Morkery Wood is probably the best, with the highest number for one day this year being ten. Neighbouring Twyford Wood also did well, where nine were seen on 27/6. 

Yorkshire

This county gave the most exciting results. Up until now, just a handful of sightings in the south of the county had been recorded in 2016 and 2022. This year, we had three sightings from the middle of the county: at Sprotborough Nature reserve; near Guisborough; and at Askham Bryan College. 

Tues July 29th: Egg Predation

Here's a completely empty egg. It has probably been sucked by a predatory invertebrate armed with a piercer, though I couldn't see a hole when I looked at it under the microscope. It has 13 ribs, by the way. Terrible things happen to caterpillars, and eggs...

Sun July 27th: 2025 'Egg Lay' = Stupendous

A highly positive session in one of the key breeding areas of Savernake Forest yesterday. A gang of three found 24 larvae, three eggs and a few instances of predated / lost larvae.  11 were found on one tree. Larvae will be followed in situ.

One of the eggs may well have been laid on Sat 26th (certainly no earlier than Fri 25th) - 

So, there may be the odd female still at work in Savernake.  

Larvae were a mix of late 1st instars (some skin changing) and early 2nd instars. Here's a skin changing L1, note the diagnostic yellow 'collar' -

Here's an early L2 larva, showing the distinctive feeding marks and the midrib isthmus which larvae try to defend against invertebrate predators (or possibly desiccated in the heat) - 

But many succumb to predation, especially L1s. This Early L2 larva has probably been sucked by a sucking bug -

Onward! 

 

Fri July 25th: Stumps Drawn...

It took me several days to recover from the utterly stupendous Knepp Purple Emperor season. For a week I felt like Ben Stokes after back-to-back test matches (you need to know your cricket quite well to understand this, but it means extreme enknackerment...).

Today, I managed to make it to Savernake Forest, which regularly produces late sightings, in time to see my last of the year - a worn, frayed and woefully inactive male in the infamous Dead Beech Glade. At 3pm, as Joe Root reached his century at Old Trafford, he rose to the challenge of seeing off a Stock Dove. At that point I drew stumps. Here he is, small and dead centre, wings outspread - 

BUT, given the advanced state of larvae - there are 3rd instar larvae in Sussex, already - there is a chance that a few 2nd brood adults will emerge in the early to mid- autumn, if the long hot summer continues. Watch this space, and burn the butterfly books (the Emperor's already burnt mine)...

Better still, it looks as though the 'egg lay' has been massive. I have been conducting standardised counts of autumn larvae in Savernake since 2009, and suspect that 2025 will prove to be the best year in a run of 17 years. Today, I was finding larvae at the rate of one per 11 minutes - that's mega. Most were 1st instars on leaf tips, like this -

This will be the autumn to look for new colonies, in new districts and new counties. Top of my personal hit list is the Forest of Dean. Bring on the autumn Dangle Leaf Season, and keep following this Blog - this Emperor year is far from done.  

 

Sun July 20th: Update, Herefordshire Comes Out!

I've been hors de combat, having imbibed too much fermenting oak sap, and have also been away at a family gathering in Cornwall (my branch of the Oates family emanates from Perranwell & Frogpool).  

Whatever, the tail end of the 2025 Emperor season stumbles on.  The great news is that Purple Emperor has been found in woodland near Ledbury, which means that Herefordshire is Purple (as I've long suspected).  

Also, we have another sighting from Yorkshire, this time from just west of York. These are not wedding release sightings, though they may be casual release of bred specimens. Yorkshire to decide for itself (as in, 'You can always tell a Yorkshireman, but you can't tell 'im very much...'). 

Lancashire, you're in trouble: the White Rose is becoming Purple. Send for Wallace & Gromit...

Meanwhile, four Emperors were seen at Knepp yesterday, Sat 19th, including two females on an oak sap 'feeder tree', one of which was in good condition. 

Back in Savernake, we had 2nd instar larvae before mid-July (and Sav is a 'late' site). That means there's a chance of some wild second brood individuals being seen in early autumn, perhaps especially at Knepp, but if and only if the fine weather continues into August and September. 

Watch this space, a new story is unfurling... 

This Blog functions all year round, and because we have - for the first time since 2018 - a big 'egg lay year', there should be a lot of larvae to be found this autumn, including in new districts. The coming 'Dangle Leaf Season' could be mega...

   

 

Mon July 14th: Closing Time at Knepp...

Saw my last Knepp Emperors of 2025 today. It was hard work. No males, but I watched five females sap feeding during the late morning, notably this one who is in remarkably good condition (the others were worn and ragged) - 

From 12.45, one by one they ceased feeding and flew off to do some serious work - egg laying. 

The 'egg lay' this year should be very high indeed, though that tends to lead to high autumn and winter predation rates...

There's another week or ten days left to the season at later sites, like Savernake, but I'm sure there wont be any August sightings this year. There may, though, be some second brood sightings in October, if the warm weather continues...

Intrigued by a confirmed sighting of a male in a garden in Guisborough, just SE of Middlesborough (and just in N Yorks) on July 11th, next to Guisborough Woods. Such sightings tend to be put down as 'releases', or possibly as Butterfly Confetti at weddings, but please don't underestimate the Purple Emperor butterfly: He seeks nothing less than temperate world domination...

Also, good to see several Dark Crimson Underwings feeding on the Emperor's sap runs yesterday and today. It's a class insect.

 

Sun July 13th: Going Over Fast...

The season is ending fast at Knepp. I walked Week 5 of the Knepp PE transect this afternoon. I expected 5-6 but struggled to see a single female. Part of the problem is that the 'feeder trees' (sap-producing oaks) have all dried up along the route, and the Emperors have moved elsewhere, to where the sap is. Normally, the PE season here lasts into Week 6.  

All the males I'm seeing here are in their last hours, though there are still a few fairly fresh-looking females around, the odd one of which will linger on for maybe another week. Here's the best of today's females - 

Imagine this: the Purple Emperor season ending in mid-July. That's what's happening now. 

What do you do when the party's over?

Find another party! Will the Clouded Yellow please show up... ... ... 

Sat July The Glorious 12th

Back into the fiery furnace, at Knepp, in 30 Celsius (anyone having problems with this heat, just say the magic word, 'January'. Problem solved). Managed to see some 36 Emperors and Empresses, including 20 females - and I wasn't butterflying for much of the afternoon.

One male and two females were in reasonable condition, the rest were worn and torn - seeing out their days feeding on oak sap. Here's a female (upper) and a male (lower) feeding close by, at high noon today - 

All bar one of the 36 I saw were on or around oak 'feeder trees'. The exception was a middle aged male on territory, having a bad time dealing with a very stroppy immigrant Painted Lady male. Grey pilgrim Lady males are the only butterfly that can mix it with Emperors on territory, but home grown ladies don't exhibit that behaviour at all. Here's today's brave Horatio holding forth in one of the top Emperor territories - 

Tomorrow, I'm going to attempt Week 5 of the Knepp Purple Emperor transect. I hope to get into double figures, but everything depends on the number of feeder trees along the route.

Fri July 11th: Doings in Gloucestershire

This is the first female I've ever seen in Gloucestershire, and she was in my own parish too - 

She was one of two females, and a male, seen feeding this hot afternoon on a classic diseased oak feeder tree, along the lane between Sapperton and Frampton Mansell, above the River Frome valley (near Daneway Banks on the butterflying map) -

Interesting, no males have been active on the nearby lime trees territories lately - nationally, they seem to have forsaken the territories for feeder trees in this heat.

Best of all, I can reveal that a magnificent male has visited The Daneway Inn pub at the foot of Daneway Banks large blue reserve - and smashed things up there.

There is only one Lord of the Butterflies, and He does not share power...

Back to Knepp tomorrow...

 

 The North, update

Leicestershire has recorded sightings in nine known habitats, and they have discovered two new sites: Queen Elisabeth Jubilee Wood, and Bradgate Park.

In Nottinghamshire, Cotgrave forest has shown well and is still the best site in this county. 

There may well be a bigger population in Sherwood forest/Clumber park, but they are spread over a huge area. Only a few sightings have been recorded, although 10 eggs were found along one ride recently. A new site is a wood just east of Bolsover. As usual, Wellow Wood always produces a few sightings; the most interesting has been in a pig pen on the western edge of the wood where three were seen, which eventually flew up to the edge of the wood.

Stephen Mather's [Nottinghamshire recorder] distribution map showed 5 sites at the end of June.

Apatura iris on Banana...

People are forever baiting for Emperors with bananas, despite the paucity of records of the butterfly actually visiting banana baits - and on the rare occasions that Emperors do visit bananas, it seems to be more for the additives (sugar, molasses, rum, water, shrimp paste, human xxxxx, etc.) than the actual banana. 

I know of only two records of Apatura iris visiting pure bananas in Brexit Britain, both involving females. 

Neil Hulme is even more scathing about the practice than me, and habitually removes banana baits. 

Nonetheless, here's a male feeding on a very dry banana skin beneath Patrick's Tree (a classic oak sap 'feeder tree') at Knepp, photoed by David Land on July 5th (with thanks to David for the photo) - 

The male had been feeding on oak sap in the tree above, but then descended to the track in search of moisture - but the track was very dry, and devoid of cowpats. Hence the brief banana visitation.  

Please note that Emperors have long stopped descending to the tracks to feed for the year, though you might just find a dying male down.  They only do it during the first few (3-4 days) of their lives.  

Onward!

July 7th. Back in Savernake...

Struggled to count 12 males in territories along Three Oak Hills Drive in Savernake this afternoon. They weren't very active, perhaps because it was actually too calm (a bit of breeze disturbs them into flight). They are just past peak now in Savernake.

Good to be shown a trio of hatched pupal cases. All 11 pupae found by UV torching in Savernake successfully hatched. The pupal cases can last for months, depending on storminess, and they continue to flouresce under UV light. 

Also good to see the first eggs of the year. The 'egg lay' should be very good indeed - 

Incidentally, we have a record of an egg being found on the leaf underside in Savernake! That's a first, nationally, and backs up my sighting last week of a female seemingly laying on a leaf underside, but too high up in a sallow in Sav. Think trolley, off; think shopping trolley upside down in some concreted urban culvert, in Swindon where the  shadows lie...

There are 1st instar larvae in Savernake Forest too, already.

Elsewhere, Patrick's Tree is still producing the goods at Knepp.  

Thurs 10th Update. Succumbed to exhaustion and heatstroke. Failed to get out. Reduced to counting butts in my garden (30 year record counts of Comma and Peacock). Very interesting to see Ladybirds Stop Play at Lords...  

 

Foxley Empresses. A really good morning (9th) over at Foxley Wood in my home County of Norfolk. An Emperor glided past as I left the car park. I stood and watched as another came by landing in a tree above my head. This one then flew down and onto a small Oak opposite. A look through the bins revealed another on what turned out to be a tiny sap bleed. Within half an hour four Emperors had gathered plus a couple of Red Ads, four Commas and several Speckled Woods. I walked the main ride and had two well worn males come down. Returning to the car and the Empresses were still active three hours after first seeing them. Good to show others this delightfull sight.

Tues July 8th: OMG, they're going over!

Yes, incredibly, the Knepp Purple Emperor season is very much on the wane, already. 

I did the Knepp PE transect today. I expected to see 25-30, but struggled to count 11 in perfect weather conditions (last week's count was a record 80).  

They've plummeted.

However, it's clear that males aren't occupying territories much in this heat, so I probably under-recorded. 

Also, both sexes are clustering around 'feeder trees' producing oak sap, and there are few of those along the transect route this year.  

One tree in particular is proving immensely attractive, with 2-6 adults (both sexes) ever present. There are 51 people in this photo, admiring Emperors getting plastered on Patrick's Tree -

Also, Empresses have the habit of going shading in hot weather, often for long periods. Here's a middle-aged female who went shading in a bramble bush for over an hour today -

My advice is don't travel long distances to visit Knepp this year, and don't come at all after the coming weekend, they'll be over. If you do come, visit Patrick's Tree, along the White Route (but note that it doesn't function in a SW wind).

Mon July 7th: Windy Sunshine...

A useful drop of rain here in Sussex, yesterday afternoon and again around dawn. Then a few hours of grot. Then windswept sunshine.

The first Purple Emperor of the day appeared with the first glimmer, at 11.07, around the most favoured feeder tree, 'Patrick's Tree'. Prior to then, I'd only seen singletons of Meadow Brown, Gatekeeper and Purple Hairstreak.

Patrick's Tree was on top form, with 2-6 Emperors and Empresses (mainly Empresses) ever present. The highlight was this near-pristine female basking low down on the main trunk -

Elsewhere, the butterfly was hard to find. I've got a strong feeling that the Purple Emperor is very much on the wane here, but I'll find out tomorrow, in better weather (too windy today), when I walk Week 4 of the Knepp PE transect (a 2 mile long single species count with a mighty big recording box, established in 2014. It's Kosher).  

The Knepp season may tail off fast in the coming heatwave...

 

Sun July 6th: Rolling Thunder...

The rolling thunder review at Knepp. No lightning, but myriad rumbles and three hefty afternoon and early evening showers. Some warm sunshine in between though, from late morning.

Good to see a 3-4 day old male feeding on one of the tracks, probably the last to do so this year. Also, a little sallow searching still going on, suggesting that there are still some females to emerge - and we watched a pristine female.  

Again, though, most Emperors and Empresses were feeding on oak sap. This frayed-around-the-edges male had imbibed too much sap, and fell out of the feeder tree to crash land on a ragwort flower. 

 

Note that his tongue was not out and he was not feeding. 

This day half a century ago, the first males of the season were just emerging in the woods to the north of Knepp. Fifty years on, the Emperor started here on June 15th and the season is halfway through...

I used to regard July 6th as National White Admiral Day, when camilla was well out and resplendent. Of course, with earlier emergences they're now well past peak by that day. Here's a somewhat battered male from today - 

Sat July 5th: Gloom, Drizzle & Oak Sapping

Can't remember when we last had a poor day...

But today was grotty at Knepp: as dull as Peterborough (or anywhere else) on a Blue January Monday, with pulses of drizzle.

However, the Emperors carried on feeding in all but the worst of the grot. I managed to see about ten females and half a dozen males, all on or around oak sap feeder trees. 

The place to be was Patrick's Tree -

The best photo I managed was this -

Males have been scarcely using territories all week - except when territories are close to feeder trees. In cloudy weather, when males are on territory, one good way to find whether there's a male present is to send up a drone -

The Emperor sallies forth and attacks the drone, but the downdraught pushed him back, unharmed. Here's a drone (and a distant Easyjet) in a classic canopy gap territory.  

  

 

Independence Day

Back at Knepp today. It took some time to find where the Emperors were - few males were on territory (a bit windy, but even many sheltered territories were empty) and only a few were sallow searching (very soon, they'll stop doing this altogether, and take the mornings off). 

It turned out that most males and many females were busy feeding on the oak sap trees. They are desperate for sustenance in this heat. Here's today's best photo, showing five feeding together - 

This is the first time I've managed more than four in a feeding vista. At one point at saw seven on that short bough length. They are forever being disturbed by fascist hornets when feeding on sap.  

It may be that this weekend's shift to cooler, moisture weather will bring a behavioural change, and males will become more territorial.

Also good to see Purple Hairstreak (in excellent numbers this season) feeding on brambles and ragwort flowers, something they only do in heatwave conditions - 

Other news. Great to hear of a Emperor in the New Forest, a female at Broomy Plain last week. There are very, very few recent records from The Forest, but do people look there?  

Great Emperor seasons are judged by Emperors turning up in unexpected places off piste, like Broomy Plain...

 

3rd July Update

Not too much news at the moment. I've been at home working local sites, with small populations, but am heading back to Knepp tomorrow. The Emperor may be a trifle past peak there... 

Emperor males have stopped coming down to the rides to feed at the earlier emerging sites, like Knepp, though they should be doing it for a few more days at the later-flying sites. This weekend may be the last chance to see them on the ground at places like Fermyn. 

We are hearing of more and more records of both sexes feeding on sap bleeds on oaks in this hot weather. These bleeds are hard to spot as they're small features - not huge splurges of black treacle running down a tree trunk.  Watch for hornet, wasp, greenbottle and Red Admiral activity, as they also love oak sap. Here's a female at sap - 

Soon, probably midweek at Knepp, the males will suddenly stop sallow searching during the mornings, and become afternoon butterflies...

Tues July 1st: Welcome July...

34C in London...  Broiling throughout the Empire.

At Knepp, Neil and Kat spent the day counting Emperors over as large an area as possible. They totalled 283. Now, that's about 100 less than the peak full day count of 2018, BUT the site was far more open then - in particular, sallow thickets are doubled in height since 2018, which greatly reduces sightings of females and sallow-searching males.  

They also walked Week 3 of the Knepp Purple Emperor transect. This totalled 80, by far the highest week count in a single-species transect which has been running since 2014 (the highest count in 2018 was 66). 

Unless the weather collapses badly, and the Knepp Emperors get blasted away - as happened last year - 2025 will comfortably better 2018's transect tally. Then, the six week transect total was 200, we're on 164 already, with three weeks still to come...

On the debit side, as we predicted, males have stopped coming down to feed on the Knepp tracks. Both sexes are getting seriously tanked up on oak sap instead (for those who know Knepp, Patrick's Tree is providing numerous photo opportunities).  

I was in Savernake, where I counted 17 along Three Oaks Hill Drive, including an egg-laying female who seemed to lay one egg on the shaded underside of a vertical leaf (too high up, couldn't see it). I'd expected more than 16 males, but they were suppressed by heat and a total calm. Nonetheless, I think that's a record count for 3OHD, though I've never counted there religiously.   

One male was feeding on The Column (an 18th century excrescence), which they do in hot, calm weather. Here's The Column - 

and here's Himself feeding on it (before he flew off to smash things up) -