Sat July 11th: Season Ending

This photograph of an old male on territory in the 'Dead Beech Glade' in Savernake Forest, Wilts, is probably of my last Purple Emperor of the year. You can just make out a pair of antennae and the front of the forewings - 

It was taken at 2.15pm on Saturday July 11th. Time was when the Emperor season was only just beginning on that date!

All we saw during an exhaustive and exhausting search of Savernake's best territories was this and another faded male, though there must be the odd female still on the wing.  

July 8th: Heatwave Intensifying...

Today brought very difficult weather conditions in which to work Emperors, especially late in the flight season: cloudless, calm and hot from early.

In such conditions, late on in the season, Emperors tend to stick to the vicinity of their feeder trees, which are usually sap bleeds. Sap runs are never easy to find, and can switch on and off from day to day. This year, they have been even scarcer than usual - Patrick's Tree, normally Knepp's No 1 feeder tree, has hardly functioned...

I was in a new part of Savernake today, and quickly learnt that weather conditions weren't right for surveying. The one sap run there, the best I've seen anywhere this year, attracted half a dozen male Red Ads, and briefly this old male Emperor (and it is male, it's completely lost its purple iridescence) -

The signs of an ageing season were everywhere, including this pupal case remnant, from two weeks ago -

and the next generation of larvae is advancing. Here's a late 1st instar larva, soon to change to the 2nd instar, and gain its horns - this early, rather begging the question of whether we'll see some 2nd brood Emperors on the wing this autumn???

Elsewhere, it looks as though the Purple Emperor is over in Alice Holt Forest, Hants, already...

  

Tues July 7th: Going Over?

Time was when the Purple Emperor season would normally start on or around July 7th. This year, the butterfly is now past peak and probably starting to go over at early sites in the south east. The length of the tail will be determined by the intensity of the current heatwave.

The woodland vegetation provides a better indication of real time than our calendar. Look at the oaks, and the sallows, and everything else. It's late July out there...

It appears that 2026 is at best a rather modest year for the Purple Enperor, numbers-wise - but populations have been hard to monitor due to extreme heat and unforecast winds, generating a pattern of days of relative activity punctuated by days of extreme lethargy. 

Yesterday, I visited the central Malverns, straddling the Herefordshire - Worcestershire border, where Emperor males were discovered genuinely hilltopping last year, and were seen again last Wed and Thurs. 

These are the first records I know of Emperors hilltopping in open terrain in this country, though odd individuals have been seen on the crest of the South Downs (seemingly wandering over, rather than setting up and defending territory). 

It was too windy yesterday, with a Fresh westerly blowing on the Malvern tops. We saw a nice scatter of old sallows with suitable-looking foliage on the western (Herefords) slopes. Here's the habitat, where males have been perching on bracken tops - 

Elsewhere, Emperors have been seen in three sites in Yorkshire (but none in Lancashire), some new places in Derbyshire, and has been rediscovered in Devon. 

 

Fri July 3rd: an 'average' year...

Walked the Knepp Purple Emperor transect this afternoon, for Week 4. Counted 32.

That makes 2026 an average year for the PE here, even if they burn out fast in the coming heatwave (which they may well do).  

They have been very hit and miss here this year - localised and episodic.

Today was my last day at Knepp.  Off home early tomorrow, to work Savernake and elsewhere...

Here's my signing off photo from Knepp - 

 

 

Thurs July 2nd: Hungover...

Struggled to see Emperors at Knepp today. It was too windy, yet again, but the two sap run trees which had been heavily favoured these last few days both drew blank, and most of the favoured male territories were empty too. Sap runs can suddenly switch off.

Conclusion: both sexes got so plastered during the football last night that they took the day off, hungover. I can't think of any other explanation...

The best I managed from today was this photo of a female sapping next to a Red Ad on the feeder tree next to the tree platform down Green Lane - 

Tomorrow's my last day here. Need to finish on an almighty high...

   

The Purple Emperor Rescues England

Watched the first half of England v DRC. Decided the cause was lost, so went out Emperoring on bike, listening to the match on the radio.

Both England's goals were set up by the Purple Emperor butterfly. Both goals resulted from magnificent 'tumbledowns' (mated female rejecting a wont-take-no-for-an-answer male). Here's Kane's winning goal -

Interestingly, there are still a fair number of fresh-looking males around at Knepp, and males are still 'sallow searching' (for females and female pupae).  

 

Tues June 30th: Apatura iris in cop

Briefly, as I'm too tired. A pair joined at 4.05pm on the shady leeward side of a feeder oak, just 25' up, after meeting in flight. No courtship (he didn't even ask her name...).

They remained together, motionless, wings closed, for a marathon 4 hours and 2 minutes. The average duration prior to this observation was 3 hours 42 mins, from a sample of 19 pairings (now 20). Gentlemen of England, Ladies even, we are outdone, by a butterfly...

We managed to show them off - and a lot more - to one of Knepp's famous Purple Emperor Safaris (estab. 2014) - 

All previous pairings I've seen have been in the tops of tall trees. Really good to see them so low down.  At one point I saw 6 males and 2 females in a vista by that feeder tree.

Onward!

 

 

Mon June 29th: Knepp Transect Data

The Purple Emperor is now at peak at Knepp. 

Today, I walked the Knepp PE transect. This runs down 2km of oak-lined green lane and takes around 2 hrs 30 mins to walk. Weather conditions were Good, with Emperors nicely active (a wind sprung up towards the end - Knepp is a surprisingly windy place).

I totalled 38, including 5 females. 

That's about par, suggesting that the butterfly is in average numbers at Knepp this year (though way down on last year's stupendous showing, which produced a record individual transect count of 80!). 

However, if another extreme heatwave comes over, they'll shoot over early (as happened last year, and in 1976) - in which case this year will become a below average year...

At last, some of Knepp's oaks are producing sap runs. Both males and female cluster around these 'feeder trees', which means they tend to disappear elsewhere. 

Here's some feeder tree action from 2025 -

  

Sun June 28th: The Wind Returns...

Far too windy at Knepp today, again, after a quiet and productive day yesterday. Most of the male territories were unoccupied today, windswept. There was, though, some good activity out of the wind, along east-facing and north-facing edges.

Elsewhere, the Emperor seems to be having a good year in Lincolnshire. Down south, numbers seem at best moderate, but we can't get a reading when it's either stultifyingly hot or blowing a gale...

Here's the wrong Emperor, the Emperor dragonfly, eating a Marbled White - 

 

Sat June 27th: Muggy, Still & Cloudy

Change in the weather, to warm, muggy cloud, with hardly a breath of wind. Perfect Emperoring weather! They love it, and are fully active.

Back at Knepp, after a week elsewhere. People had struggled to see PEs at Knepp during the heatwave, but that changed today: most of the favoured male territories were occupied, with males sailing around joyously, and some females evident. 

Three 'tumbledowns' were seen: descending spiralling flights with "Hi! I'm Andrew Tate" males circling around an "I'm washing my hair tonight" mated female. At the last second she will do a U-turn, hoping that he will crash land and smash up his top range performance motor. This behaviour was first observed by KJ Willmott at Bookham in 1983 - Heslop never saw it, nor me till Knepp. It's common at Knepp during the second half of the flight season.

Here's a female basking in a sloe bush yesterday -

And here's a more typical view of a female (again, yesterday): they spend hours sulking in sallows, all but out of view - 

Today, though, Sunday 28th, the wind has returned. Leeward, leeward and leeward...

June 25th

This time 50 years ago, during the midsummer heatwave that immortalised the Long Hot Summer of 1976, the first Emperor of the year was seen on Midsummer Day, June 24th, by KJ Willmott, at Bookham Common. That equalled what was then the known earliest PE record (the Marlborough College record of 10/6/1893 had not come to light). The following day, June 25th, the first was seen in Alice Holt Forest. Then the Emperor erupted...

Right now, males and the first females are emerging nicely at most sites. In particular, this is the week to look for males feeding on the rides: watch out for the shark's fin wing shape, especially on or around any form of dung.  

In hot weather, and especially in bright sunlight, they tend to feed with their wings tightly closed, opening up only if they crawl into shade. However, you can persuade them to open up by slowly casting your shadow over them IF they are fully absorbed in feeding - watch for the probing yellow tongue and the rocking head. If they take off, freeze - play musical statues. Be careful not to make footfall vibrations, to which they are very sensitive.  

Note that they often take a break whilst feeding, flying up into a nearby bush to clean their tongue for several minutes before descending again. Watch out for the second coming...

Nationally, they'll probably stop descending to feed on the rides shortly after the coming weekend - only males aged 1-4 days do it, plus the odd female in extreme weather.

They should move on to the sap runs soon, to get plastered...

Back to Bernwood 25th June 2026

 At least 4 male emperors found throughout a four hour trial by heat with temperatures reaching 36F.Late morning I flushed a male from dog poo which flew up about four feet to sit for twenty minutes on a shaded blackthorn leaf before descending for another fifteen minute feed on the dog poo.It then flew back into the blackthorn and perched again for twenty minutes on a shaded leaf this time no more than three feet above the ground.Conjecture I know but maybe it did this because if it went to the top of the oaks it would be too hot?

Midsummer Day

Serious heatwave, breaking the record UK temperature for June (it may be broken further tomorrow)... and dead calm and excessively humid too.

Visited the north-west sector of Savernake, where I've always struggled to see Emperors, having never managed to find the male territories. Great to be shown an about-to-hatch pupa, from a larva my Savernake colleagues, Gary and Sarah, have been following since last Sept, called 'Rainman' (because he was found in heavy rain).  He hatched at about 1pm.  

Here's the empty pupal case of another pupa, again from a long-followed larva - 

I particularly wanted to see adults feeding on the mega sap run on the Bumble Oak, outside the FC loos. One was there around 9am, which I missed.  All I saw feeding there was Red Ads, Commas, hornets and the rare sap-run hoverfly Ferdinandea ruficornis (and I mean ruficornis, not the common cuprea).

Finally, here's the White Road Oak, another Savernake veteran. If you pass a small child through the portal on Midsummer Day you'll cure it of rickets...

Damn hard working Emperors in this heat, as many conk out around 1pm, before becoming active again in the evenings. Neil Hulme walked the 2 hour-long Knepp PE Transect yesterday evening, starting at 6pm with the butterflies nicely active. His count totalled 27 (including 1 female). That's a modest tally for Week 2 (the record individual count is 80, set in Week 3 last year).

 

 We visited Chedworth Roman Villa yesterday (about 10 miles N of Cirencester) and saw a male PE fluttering around which we later found on one of the display boards. Here he is extracting sweat from my daughter's hand! Ironically, we'd been to

Sapperton the day before and seen none at all!

On 19 June I had an amazing encounter with a female Purple  Emperor in  Whitecross Green Wood in Oxon. I was looking over one of the woodland ponds when the PE dropped out of the trees to perch on Amphibious Bistort covering the pond. It sat there for several minutes, presumably drinking as the day was very warm, before flying off back into the canopy. I managed to get the posted photo which I am very pleased with and I believe it depicts behavior rarely documented by the camera. There were also several White Admirals present in this superb wood.

Foxley, Norfolk. 23rd June

A bit of over night rain was promising so an early start before the heat hits. Unfortunately 20 miles away at Foxley Woods it seemed they had very little and the main ride was bone dry. The first Emperor was seen at around 9am and the initial sightings were all Sallow searching. There was a peak in activity at 10ish when three were seen by the bench at the cross tracks. One male constantly buzzed my face and I thought would come to ground but no luck. At least six seen but probably still early days. Paphia and Camilla are doing well but the grassland species numbers are quite low. I will leave you with the only shot I got, use your imaginations.

June 23rd: After the Thunderstorm...

Heavy thunderstorms in the western parts of the Empire yesterday evening. That meant wet rides and a steamy forest today, and the descent of hungry Emperors...

I saw three pristine males coming down to feed in one of the Braydon Forest woods, NW of Swindon, notably this beauty - 

This is a newish site, with a building population. The male territories have yet to be discovered.

So we looked for a male territory in a classic sheltered wooded hilltop with oaks and small-leaved limes (which PE love). Nothing. They're not there, though they must be assembling somewhere close by. I'm cross with them. 

Instead, Herself appeared and laid two eggs right in front of me. Now I've got to look up my earliest ever egg (which I shall do after the football) -

Elsewhere, PE started in Dorset and Glos (Sapperton) on Sun 21st, and has now been seen in Norfolk (in the Yare valley again) and Notts.  4 seen at Sapperton today.

No reports of astronomical numbers yet, and it doesn't (yet) appear to be a particularly great year for them, but the weather this week isn't easy to work in.

Advise: in extreme heat, work the evening flight, between 6pm and 7.30.   

Right, football.  

Bernwood Forest 22nd June

At least three coming down from the Oaks late morning. This one was present for at least forty minutes  imbibing from one of the few areas of damp ground on a track through the woods.He found it a struggle to find anything to his liking, regularly flitting along low to the ground searching for that sweet spot. Always good to get my initial adrenalin rush of the season as I glimpse that flash of glorious colour.

Sat June 20th & Sun June 21st: Heatwave Coming!

Sat 20th: a little too cloudy at times. Savernake had a welcoming party out for me, in the form of a large (Emperors are unusually large in Sav) male flying down Grand Avenue towards me as I drove in from the Burbage end (stop, switch off and Squirt Windscreen - but he hurried on by...).

Then a magic 40 minutes with this pristine male, who was struggling to find anything to feed on -

Eventually he found a squashed fox scat (identifiable by smell and the presence of Woodland Door Beetle wing cases!) -

A search of the Three Oak Hills Drive male territories, in imperfect weather, produced lone males in three of the primary territories (and, as usual, none at The Column, where everyone goes, which is a secondary territory).  

Incidentally, PE started in Savernake on Friday 19th, when the last of the followed larvae there pupated. PE also started in Bentley Woods, S Wilts, then.

Sun June 21st.  Not many people out Emperoring today, deterred by the heat.  Today, the Emperor started in Glos, with 2-3 males active at Sapperton Broad Ride (Mick Peacey's been checking daily, so this is Day 1). Here's one up on a favoured lime tree - 

 

The Purple Emperor is now out in virtually all known counties: Dorset, Glos and Leics all started today. We've yet to hear from some of the northern counties. Numbers are low to modest nearly everywhere (Fermyn Woods may be in the lead at the moment). 

In the coming heatwave, males will be looking for food on the rides in early to mid-morning, and thereafter intermittently throughout the day. The rides are, though, very dry. Dog mess (commonest near to parking areas) will be favoured. 

Males will be active on territory from about 12.30 to 2.30-ish, but may then conk out for a siesta, before having an evening flight from 5.30 to about 7.30. The evening flight is terrific. 

Both sexes will readily visit oak sap runs, but these are hard to find (watch for hornets and Red Ads), and flow intermittently. Here's a cracker of a sap run on the Bumble Oak, a named veteran oak close to the FC loos at Postern Hill in Savernake. Note the white bits - that's what the Emperors favour -   

Fri June 19th: Heatwave Starting...

Again, relatively modest numbers at Knepp today. Males are 'sallow searching' during the mid- to late mornings (searching the sallow thickets for females and female pupae...). Here's one from today, who paused briefly on his travels -

 4 males came down to feed on the tracks today, but the tracks are very dry and there isn't much for them. This male made do with dry cowpat -

Meanwhile, Knepp's famous Tamworth pigs know how to cope with heatwave conditions -

Elsewhere, the first Emperors of 2026 were recorded in Savernake Forest today (I'm heading there tomorrow).  Most of the more southern Purple counties have now declared themselves in purpuratum for the season, but not Gloucestershire. Further north, the first males were seen in Lincolnshire today.

This will be the key weekend this weekend for photographing males feeding on the ground (mornings and late afternoons are best, usually). So, to the woods, the lot of you! Enjoy...

 

Thurs June 18th: Knepp Kicks Off!

Much better weather at Knepp today, without the irritating wind. However, an unforecast band of rain came over at 2.15pm, lasting till 4pm. Then the sun came out strongly and the Emperors went berserk (they even launched themselves at a Chinook helicopter, albeit rather lamely, and an Egyptian goose [new to the Purple Bird Hit List]). 

One pristine male down on the track by Patrick's Tree around noon - 

They do seem rather patchy, with some popular territories still unoccupied, and are most numerous close to the younger sallow stands, suggesting that the breeding grounds have shifted. 

An indication of how slow the season is here is provided by the fact that Ringlet only started at Knepp today.  

I had a close encounter with a freshly emerged female Purple Hairstreak, though this species too isn't well out here yet (I worked the evening flight, but only saw 10) - 

Knepp's Purple Emperor Walk is now up and running - same as last year, with PE HQ in the black barn down Green Lane -

Elsewhere, 10 seen down on the rides in Fermyn Woods today, and Worcestershire has declared itself Purple for the season.  This weekend is going to be Mega...

 

Wed June 17th: It's a Girl!

Here's Persephone, of Knepp. She was found as a final instar larva by UV torching at night in early June, by Neil Hulme. She had her final meal on the leaf upperside early on Sun June 14th, and then crawled about .5m to a leaf underside that afternoon, to pupate. 

She was head up, spinning a silk pad on the 15th, then turned around, head down on the 16th. She pupated this morning (17th), and revealed herself to be female (the pupae are easy to sex). 

So, a three day process, which is unusually quick. She wont emerge before July 7th.

Not too much progress at Knepp today: the morning was too cloudy and the afternoon too windy. 

Elsewhere, the Emperor has now been seen on the wing in Hertfordshire, Warwickshire (Heart of England Forest) and - here's the big one - Northamptonshire (Fermyn Woods).

This weekend should be mega...

Tues June 16th: Outgunned, by the Lady!

Not too much happening on the Purple front today, on this the opening day of the old coarse fishing season.

At Knepp, no big emergence yet, and none recorded feeding down on the tracks again (but the tracks are all dry and devoid of cowpats etc.). 

Males were seen sallow searching (for females, and female pupae) for the first time this year.

Instead, we had a significant influx of Painted Ladies, including this lovely female - 

For an hour around noon, Ladies were moving due north at an impressive rate.  

This is good news, as male immigrant Ladies can be highly territorial, setting up territories in canopy gaps from mid-afternoon - and sparring off with Enperors. Immigrant Lady males are the only butterfly in the UK which can compete with Emperor males on territory, so expect some good dog fights up in the canopy.

I'm expecting a good emergence of Emperors soon - Big Bang (the main emergence) must be imminent.    

 

Mon June 15th: Herself Appears!

Sunshine on a SE breeze (it was NW yesterday).

A steady emergence of Emperors at Knepp. I walked the PE transect, and counted 13, which is good for so early in the flight season. The tally included the first female of the year, here and nationally. This may be the earliest an Empress has ever been seen in the UK...

None was seen down on the tracks feeding, but the tracks have dried up and there was no dung on them today (it would help if the cattle wandered down during the night...).  

A nice hatch of Purple Hairstreaks today, a freshly emerged Peacock (already!) and another influx of Painted Ladies and Red Ads. 

Vicious Thug of the Day goes to this male, who chased off a Blue Tit and a White Stork -

Elsewhere, the first Emperors were seen today in Bernwood Forest, Oxon (Waterperry Wood).

Onwards, and Upwards...

 

Knepp Sunday June 14th

The wind did drop today and the sun shone unblemished until after mid-afternoon, when it became a trifle too cloudy.

There was no mass emergence today, just a doubling of sightings, from six yesterday to 12 today. And just the one male seen feeding down on the tracks.

But it is still very early days, as illustrated by this photo of a larva starting the process of pupation there this afternoon -

S/he is unlikely to emerge before July 7th. It may just be that there'll be a longer than usual emergence period this year, but we'll see...

It's still very early days everywhere. As far as I know only Surrey, Sussex and Hampshire have declared themselves in purpuratum so far.  

 

Knepp Kicks Off!

I saw 6 Purple Emperors at Knepp this afternoon. The first was this freshly emerged male, who attacked me on my bike, before settling to feed on the track for 20 minutes - 

 He attracted quite a crowd of admirers. Here's his underside -

Most interesting was this male, a distinctive specimen missing one wing tip. He was seen and photoed at 12.15 yesterday, near Patrick's Tree (for those who know Knepp) - Knepp's first sighting of the year. In mid-afternoon today I found him on territory up in the oaks half a mile to the west, near Green Lane Pond (ditto) having flown into the breeze - 

This counts as a Mark & Recapture record! The other fragments of M&R records I have suggest that young males are highly mobile, but old males can be sedentary.  

Elsewhere, first Emperors of the year seen today in Alice Holt Forest, but none today in Savernake.

We need the wind to drop...

We're Off!

Welcome to the 2026 Purple Emperor season, which opened officially this afternoon at Bookham Common, Surrey, with these two males cavorting about -

Photo  Colin Kemp

Congrats to Colin Kemp, and indeed to Bookham. This record equals the official all-time record for the earliest Emperor, set by boys from Marlborough College way back in 1893! 

'In my beginning is my end...' 

 

Starting This Weekend

is the 2026 Purple Emperor season...

This pupa, photographed in Savernake Forest, Wilts, on June 9th is set to emerge (as a male) on Saturday June 13th - and Savernake is not an 'early' site. 

Also in Savernake, is the Bumble Oak, a veteran oak outside the FC loos at Postern Hill picnic site. It has a copious sap run, on which Emperors, Empresses, Red Ads, hornets, wasps and numerous flies feed (including some scarce hoverflies). Note the soft white sugary beads. Note that Emperors feed with closed wings, only, and are forever being chased off sap runs by hornets.

Emperors hold territories in sheltered canopy gaps up in some of the nearby oaks.  

 

Visiting Knepp

Knepp Wildland will be open for Purple Emperor visitors again this year, primarily from June 20th to July 12th (which should coincide with the peak season period).  It involves a long walk and a full day - so come for the day.

Watching Emperors feeding on Patrick's Tree, July 2025

Please park in the main visitor carpark, at the Swallow Barn visitor centre just off the A24 at Dial Post. This is now a pay & display carpark, but your parking fee will be reimbursed if you spend £20 or more in the shop and/or restaurant. Fees are £3 for 5 hrs (reimbursable) or £5 for up to 10 hrs (£3 reimbursable).

A Purple Emperor route map will be available from the shop (and also from the camping, glamping & safari centre at New Barn Farm). 

Please follow this route. It runs past most of the best spots. Bring your lunch and plenty of water, especially if it's hot. It takes 10-15 minutes to get into the sallow areas, though the odd Emperor can be seen anywhere (including along the oaks along the lane near Swallows Barn, even from the queue for the loos).   

The best male territories will be marked with Purple Posts, indicating where to stand to watch males up in the oak canopy gaps (afternoons only - the males are not on territory during the mornings, they're exploring). Other good viewing spots will be marked with Purple Bunting. 

There will be a number of volunteers along the route, helping visitors to the hotspots. Once again, Purple Emperor head quarters will be in Lower Barn, along Green Lane.

Crucially, Emperors gather out of the wind: in a west wind, they will be on the east side of the oaks, and vice versa. Never look on windward edges.  

During the first third of the flight season, Emperor males descend to feed along the Knepp tracks, especially on cowpats and fox scats - but they only do this during the first three of four days of their lives. This year, it is likely that males will not be descending to feed after July 1st.  

I will be at Knepp from June 13th to 20th, and again from June 27th to July 4th. See you there...

 

 

 fro from the camping and glamping centre

The 2026 Purple Emperor Season... Prospects and Timings

Much has happened in the Purple world these last few weeks: a cold start to May, with cool nights; then a mid-month spell of damaging localised squalls and downpours; then a heatwave with record temperatures (day and night) at the month's end. Crucially, larval development stalled during the first half of May.

Many larvae are now full grown and there are a few early pupae around (there's a BUT coming up, several in fact).  

At this range, it looks as though the first Purple Emperor of 2026 will appear on Sat June 13th, behaving appallingly badly, BUT this is not an easy season to predict (it may be as early as June 10th...).

Sallow foliage quality is very variable from district to district. This is important. In some regions, sallows responded to the 2025 heat-shocks by over-flowering copiously this spring: they produced flowers rather than foliage. The same thing happened after the 2018 heatwaves.  

Also, there have been localised infestations of Geometer moth larvae (Mottled Umber etc.), and infestations of tree hopper nymphs (+ cuckoo spit). This means that Emperor larvae have been feeding on morsels rather than whole leaves, which slows their development down (and may contribute to mortality).

Here's a recent view of sallows in one of the main breeding grounds at Knepp (May 21st), note the sparse foliage, with some dead or dying sallows:-

And here's a view of lakeside sallows at Knepp, note the white seed on the lefthand sallow and the paucity of leafage (the white stuff in the water is seed), May 21st:-

However, most of Knepp's broad-leaved sallows are fine - it's the narrow-leaved types that have suffered most. And Knepp hosts 60ha of sallow jungle. Don't worry, Knepp can cope with this...

Over-flowering and leaf laceration have been noted elsewhere, e.g. in Alice Holt Forest, Hants, and Cotgrave, Notts.  

However, sallow foliage quality in and around Savernake Forest, Wilts, is remarkably high (Sav could produce an annus mirabilis...).  

All this suggests that adult numbers could be very patchy - very good in some districts, more modest in others - BUT much depends on weather during the pupation and pupal stages, and especially during the flight season period. 

Knepp Wildland, by the way, will be open for Purple Emperor visitors again, primarily from June 20th to July 12th, with parking at the main Dial Post centre. I'll post details later. Knepp's famous Purple Emperor Safaris are also running during this period (but are fully booked - though some more may be arranged, if there's demand...).