Purple Emperor

Apatura iris (a-pa-TOO-ruh EYE-riss)

Purple Emperor, Botany Bay, 28 June 2009
Photo © Neil Hulme
 

Wingspan
70 - 92mm

Checklist Number
59.022

Family:NymphalidaeRafinesque, 1815
Subfamily:ApaturinaeBoisduval, 1840
Tribe:ApaturiniBoisduval, 1840
Genus:ApaturaFabricius, 1807
Subgenus:  
Species:iris(Linnaeus, 1758)

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Introduction

The Purple Emperor is a magnificent and elusive insect that is actively sought out by the many subjects of "His Majesty", as the male butterfly is affectionately known. This butterfly spends most of its time in the woodland canopy where it feeds on aphid honeydew, with the occasional close encounter when it comes down to feed on sap runs or, in the case of the male, animal droppings, carrion or moist ground that provide much-needed salts and minerals. Those that make pilgrimages to see this spectacular creature will often try and lure the males down from the canopy using all manner of temptations - including banana skins and shrimp paste.

The male butterfly is one of the most beautiful of all of the butterflies found in the British Isles. From certain angles it appears to have black wings intersected with white bands. However, when the wings are at a certain angle to the sun, the most beautiful purple sheen is displayed, a result of light being refracted from the structures of the wing scales. The female, on the other hand, is a deep brown and does not possess the purple sheen found in the male.

This is one of the most-widely studied and written about butterflies in the British Isles. The classic work "Notes and Views of the Purple Emperor" by Heslop, Hyde and Stockley is dedicated to this butterfly, as is the modern-day equivalent - the excellent website The Purple Empire. This butterfly is confined to deciduous woodland in central southern England, between South Wiltshire and South Hampshire in the west, Surrey and West Sussex in the east, and Oxfordshire and Hertfordshire in the north, with scattered colonies elsewhere. It is not found in the north of England, Scotland, Ireland, the Isle of Man or the Channel Islands and has not been seen in Wales since the 1930s. Colonies vary in size, some being very small with just a dozen or so adults forming a viable colony.

Apatura iris

This species was first defined in Linnaeus (1758) as shown here (type locality: Germany, England etc.).

Purple Emperor - Fermyn Wood 2-July-2014

Male
Photo © Neil Hulme

Purple Emperor - Fermyn Woods - 14.07.13

Male Underside
Photo © Rosalyn

Purple Emperor (female), Chiddingfold Forest (17 July 2013)

Female
Photo © Mark Colvin

Purple Emperor (female) Bernwood Forest Oxfordshire 4th July 2011

Female Underside
Photo © millerd

Photo Album ...


History

The table below shows a chronology of vernacular names attributed to this species. Any qualification of the name (e.g. male, female) is shown in brackets after the name.

YearNameReference
1704Mr. Dale's Purple EyePetiver (1702-1706)
1742Purple EmperorWilkes (1742)
1749Purple HighflyerWilkes (1749)
1749Emperor of the WoodsWilkes (1749)
1795Purple ShadesLewin (1795)
1832EmperorRennie (1832)
1853Emperor of MoroccoMorris (1853)

Conservation Status

Determining the status of this species has always been problematic given its elusive nature and, although its status is considered relatively-stable, is still considered a species of conservation concern.

UK BAP StatusOccurrence Change
1976-2014 (%)
Abundance Change
1976-2014 (%)
Occurrence Change
2005-2014 (%)
Abundance Change
2005-2014 (%)
Species of Conservation Concern
Decrease-47
Large Increase+69
Large Increase+135
Decrease-35

The table above shows the occurrence (distribution) and abundance (population) trends, using information from The State of the UK's Butterflies 2015 (Fox, 2015). Any UK BAP status is taken from the UK Biodiversity Action Plan (UK BAP) (2007 review).

Habitat

This is a butterfly of large expanses of deciduous woodland, usually those containing oaks, but less-frequently beech and other species.

Distribution

 

Click here to see the distribution of this species or here to see the distribution of this species together with specific site information overlaid.

Life Cycle

There is a single generation each year. The adult butterfly emerges in early July, sometimes at the end of June in good years, with a peak in the second and third weeks of July.

The chart(s) above have been correlated with the phenology plot below, taken from the UK Butterfly Monitoring Scheme. The blue line gives average counts over the full data set from 1976 to date, and the red line gives the average for the last year.

Imago

This species is best seen in early morning and again in late afternoon, when the males will come down to the ground to feed on moisture from damp earth and animal droppings. The males are sometimes so engrossed in feeding that they will spend over an hour feeding in the same place, each displaying its characteristic yellow proboscis. The males are also notorious for feeding on mud and other debris that has gathered on surfaces of cars parked within the woodland. They are also partial to sweat and readily land on observers. However, both male and female spend the majority of their time resting high in the tree canopy and out of sight.

In late morning, the males will fly off and ultimately congregate at so-called "master trees" that provide a vantage point for intercepting passing females. These trees are typically at a high point in the wood, such as trees growing on the summit of a hill, and the same trees are used year after year. Locating a master tree is one of the best ways to catch a glimpse of this elusive insect. Seeing the males battle it out for the best vantage points, with flashes of purple as the light hits their wings, is an amazing spectacle.

When a virgin female is encountered, the pair fly off and settle in the canopy where mating takes place. If the female has already mated, then she has the curious habit of descending straight to the ground, where the male ultimately loses interest and returns to his perch.

Adults feed primarily on Honeydew / Sap. Carrion and Dung are also used.

Apatura iris

Purple Emperor Female, woods near Arundel, 15 July 2007

Photo © Neil Hulme
15-Jul-2007

Purple Emperor 2009 Clive Burrows 5 [Clive Burrows]

Photo © Clive Burrows

Purple Emperor - imago - Thatcham - 24-Jun-04 (07) [REARED]

Photo © Pete Eeles
24-Jun-2004

Purple Emperors - Fermyn Woods 18.07.2013

Photo © Neil Freeman
18-Jul-2013

Purple-Emperor- 5D30470 Hants July 2015

Photo © IainLeach

Purple Emperor (female) Bernwood Forest Oxfordshire 4th July 2011

Photo © millerd
04-Jul-2011

Purple Emperor - imago - Thatcham - 14-Jun-11 (1) {REARED}

Photo © Pete Eeles

Purple Emperor - imago - Thatcham - 24-Jun-04 (19) [REARED]

Photo © Pete Eeles
24-Jun-2004

Purple Emperor - imago - Tajvedelmi, Hungary - 14-Jul-06 (0552)

Photo © Pete Eeles
14-Jul-2006

Purple Emperor - Fermyn Woods - 14.07.13

Photo © Rosalyn
14-Jul-2013

Purple Emperor - Fermyn Wood 2-July-2014

Photo © Neil Hulme
02-Jul-2014

Purple Emperor on car bonnet, Fermyn Wood, 8 July 2009

Photo © Neil Hulme
08-Jul-2009

Purple Emperor - Bentley Wood 5 July 2010

Photo © Trik

Male Purple Emperor, Alice Holt, 21-July-2012

Photo © Pauline

Purple-Emperor- 5D33786 Hants July 2015

Photo © IainLeach

Purple Emperor (female), Chiddingfold Forest (17 July 2013)

Photo © Mark Colvin

Purple Emperor - male - Thatcham - 13-Jun-14 [REARED]-6

Photo © Pete Eeles
13-Jun-2014

Purple Emperors sparring - Bookham Common, Surrey Aug-2013 [Rob Hill]05

Photo © Rob Hill

Purple Emperors sparring - Bookham Common, Surrey Aug-2013 [Rob Hill]08

Photo © Rob Hill

Purple Emperor Female at sap run, Southwater Woods, 5 July 2008

Photo © Neil Hulme
at sap run
05-Jul-2008

Photo Album ...


Ovum

When egg-laying, the female "strikes" the sallow, as it is known, where she enters the tree and disappears within to lay a single egg on the upperside of a sallow leaf that is in half-shade. Eggs are usually laid on leaves toward the crown of the tree at various heights. Eggs are blue-green when first laid but, after a few days, the base of the egg turns purple giving the egg a distinct 2-tone appearance. Eggs hatch in 9 or 10 days, depending on the weather.

Purple Emperor egg, recently laid, Southwater Woods, 8 July 2007

Photo © Neil Hulme
08-Jul-2007

Purple Emperor egg, well developed, Southwater Woods, 13 July 2007

Photo © Neil Hulme
13-Jul-2007

Purple Emperor egg, August 2010, Switzerland

Photo © Padfield
Switzerland

Purple Emperor - ovum - Wiltshire Wood - 23-Aug-13

Photo © Pete Eeles
23-Aug-2013

Purple Emperor - ovum - Wiltshire Wood - 25-Aug-13

Photo © Pete Eeles
25-Aug-2013

Purple Emperor ovum - Rockingham Forest 08.07.14.

Photo © Tony Moore
09-Jul-2014

Freshly laid egg, Switzerland, July 27th 2014

Photo © Padfield
Recently laid wild purple emperor egg, found on July 27th in Switzerland.
27-Jul-2014

Purple Emperor - ovum - Savernake Forest, Wiltshire - 24-Jul14-2

Photo © Pete Eeles
24-Jul-2014

Purple Emperor - ovum - Savernake Forest, Wiltshire - 24-Jul14

Photo © Pete Eeles
24-Jul-2014

Purple Emperor - ovum - Savernake Forest, Wiltshire - 26-Jul-14-2

Photo © Pete Eeles
26-Jul-2014

Purple Emperor - ovum - Savernake Forest, Wiltshire - 26-Jul-14

Photo © Pete Eeles
26-Jul-2014

Purple Emperor - ovum - Savernake Forest, Wiltshire - 27-Jul-14

Photo © Pete Eeles
27-Jul-2014

Purple Emperor ovum - Switzerland 22-July-2016

Photo © Padfield
22-Jul-2016

Purple Emperor ovum - Knepp Estate, Sussex 15-July-2016

Photo © Neil Hulme
15-Jul-2016

Purple Emperor ovum (6 days old) - Switzerland 1-Aug-2016

Photo © Padfield
01-Aug-2016

Purple Emperor ovum (1 day old) - Switzerland 27-July-2016

Photo © Padfield
27-Jul-2016

Purple Emperor ovum (7 days old) - Switzerland 2-Aug-2016

Photo © Padfield
02-Aug-2016

Purple Emperor ovum (9 days old) - Switzerland 3-Aug-2016

Photo © Padfield
03-Aug-2016

Photo Album ...


Larva

On hatching, the green larva eats its eggshell before moving to the tip of the Sallow leaf, where it rests facing the leaf stalk. It feeds by day on each side of its resting place, leaving characteristic feeding damage. After the first moult, the larva is a curious beast, being adorned with 2 horns that grow out of the head. After the second moult the larva turns light brown and moves to the fork of a twig or next to a Sallow bud, where it overwinters on a silk pad with its body flush against the surface on which it is lying.

Larvae emerge from hibernation around the middle of April just as the Sallow buds are starting to expand. The larva initially feeds on the unfurling buds, until the leaves are fully-developed. The larva will then rest on a particular Sallow leaf, which is always left intact, and from which it travels to feed, returning after it has completed its meal. When at rest, the larva also sits with the front of its body slightly raised off its leaf thereby minimising any shadow that might give its presence away. It is also beautifully camouflaged with several subtle yellow stripes along the length of its body that perfectly match those of pale veins of the Sallow leaf on which it sits.

When ready to pupate, the larva travels to find a suitable pupation site, and turns a much paler green. The larva will move to the underside of the chosen Sallow leaf and spend 1 or 2 days building a pad of silk from which the pupa will be suspended. At first, the larva rests with its head facing the leaf stalk. As the time for pupation nears, the larva reverses this position, with its head facing the leaf tip. The larva has 4 moults in total.

The primary larval foodplant is Goat Willow (Salix caprea). Crack-willow (Salix fragilis) and Grey Willow (Salix cinerea) are also used.

1st Instar

Description to be completed.

Purple emperor, 1st instar larva, day 13 Switzerland 23-Aug-2012

Photo © Padfield
1st instar larva on final day, immediately prior to ecdysis
23-Aug-2012

Purple Emperor - larva - Wiltshire Wood - 23-Aug-13

Photo © Pete Eeles
23-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 23-Aug-13-2

Photo © Pete Eeles
23-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 24-Aug-13

Photo © Pete Eeles
24-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 24-Aug-13-4

Photo © Pete Eeles
24-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 24-Aug-13-5

Photo © Pete Eeles
24-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 25-Aug-13-6

Photo © Pete Eeles
25-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 30-Aug-13 (1) [REARED]

Photo © Pete Eeles
30-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 30-Aug-13 (2) [REARED]

Photo © Pete Eeles
30-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 30-Aug-13 (3) [REARED]

Photo © Pete Eeles
30-Aug-2013

Purple Emperor - larva (1st instar) - Savernake Forest - 03-Aug-14

Photo © Pete Eeles
03-Aug-2014

Purple Emperor - larva (1st instar) - Savernake Forest - 05-Aug-14

Photo © Pete Eeles
05-Aug-2014

Purple Emperor - larva (1st instar) - Savernake Forest - 30-Jul-14-2

Photo © Pete Eeles
30-Jul-2014

Purple Emperor - larva (1st instar) - Savernake Forest - 30-Jul-14

Photo © Pete Eeles
30-Jul-2014

Purple Emperor larva (newly emerged) - Switzerland 6-Aug-2016

Photo © Padfield
06-Aug-2016

Photo Album ...


2nd Instar

Description to be completed.

Purple Emperor larva, second instar - Switzerland 24-Aug-2012

Photo © Padfield
Switzerland
24-Aug-2012

Purple Emperor - larva - Wiltshire Wood - 24-Aug-13-6

Photo © Pete Eeles
24-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 25-Aug-13

Photo © Pete Eeles
25-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 25-Aug-13-7

Photo © Pete Eeles
25-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 25-Aug-13-8

Photo © Pete Eeles
25-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 25-Aug-13-9

Photo © Pete Eeles
25-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 25-Aug-13-10

Photo © Pete Eeles
25-Aug-2013

Purple Emperor - larva - Wiltshire Wood - 30-Aug-13 (4) [REARED]

Photo © Pete Eeles
30-Aug-2013

Purple Emperor - larva (2nd instar) - Wiltshire Wood - 23-Sep-13

Photo © Pete Eeles
23-Sep-2013

Purple Emperor - larva (2nd instar) - Savernake Forest - 09-Aug-14

Photo © Pete Eeles
09-Aug-2014

Photo Album ...


3rd Instar

Description to be completed.

Purple Emperor larva 5, pre-hibernation, Wilts Wood, 11 October 2009

Photo © Neil Hulme
11-Oct-2009

Purple Emperor larva 2, pre-hibernation, Wilts Wood, 11 October 2009

Photo © Neil Hulme
11-Oct-2009

Purple Emperor - 3rd instar larva - Wiltshire Wood - 17-Dec-13

Photo © Pete Eeles
17-Dec-2013

Purple Emperor - larva 3rd instar - Wiltshire Wood - 10-Mar-14-9

Photo © Pete Eeles
10-Mar-2014

Purple Emperor - larva (3rd instar) - Wiltshire Wood - 04-Oct-13

Photo © Pete Eeles
04-Oct-2013

Purple Emperor - 3rd instar larva - Wiltshire Wood - 17-Dec-13-8

Photo © Pete Eeles
17-Dec-2013

Purple Emperor - larva (3rd instar) - Thatcham - 17-Apr-14 [REARED]

Photo © Pete Eeles
17-Apr-2014

Purple Emperor - larva (3rd instar) - Wiltshire Wood - 04-Oct-13-2

Photo © Pete Eeles
04-Oct-2013

Purple Emperor - larva (3rd instar) - Wiltshire Wood - 23-Sep-13

Photo © Pete Eeles
23-Sep-2013

Purple Emperor - larva 3rd instar - Wiltshire Wood - 30-Nov-13

Photo © Pete Eeles
30-Nov-2013

Purple Emperor - larva 3rd instar - Wiltshire Wood - 30-Nov-13-8

Photo © Pete Eeles
30-Nov-2013

Purple Emperor - larva (3rd instar) - Wiltshire Wood - 23-Sep-13-6

Photo © Pete Eeles
23-Sep-2013

Purple Emperor - 3rd instar larva - Wiltshire Wood - 17-Dec-13-6

Photo © Pete Eeles
17-Dec-2013

Purple Emperor - larva (3rd instar) - Savernake Forest - 21-Apr-14-3

Photo © Pete Eeles
21-Apr-2014

Purple Emperor - larva 3rd instar - Wiltshire Wood - 10-Mar-14-6

Photo © Pete Eeles
10-Mar-2014

Purple Emperor - larva (3rd instar) - Savernake Forest - 21-Apr-14

Photo © Pete Eeles
21-Apr-2014

Purple Emperor - larva 3rd instar - Thatcham - 31-Mar-14-2 {REARED}

Photo © Pete Eeles
28-Mar-2014

Purple Emperor - 3rd instar larva - Wiltshire Wood - 17-Dec-13-7

Photo © Pete Eeles
17-Dec-2013

Purple Emperor - larva - Thatcham - 31-Mar-11 (2) {REARED}

Photo © Pete Eeles

Purple Emperor - larva - Thatcham - 31-Mar-11 (3) {REARED}

Photo © Pete Eeles

Photo Album ...


4th Instar

Description to be completed.

Purple Emperor - larva - Thatcham - 20-Apr-11 (2) {REARED}

Photo © Pete Eeles

Purple Emperor - larva (4th instar) - Savernake Forest - 21-Apr-14

Photo © Pete Eeles
21-Apr-2014

Purple Emperor - larva (4th instar) - Thatcham - 17-Apr-14 [REARED]

Photo © Pete Eeles
17-Apr-2014

Photo Album ...


5th Instar

Description to be completed.

Purple Emperor - larva - Thatcham - 16-May-05 (2) [REARED]

Photo © Pete Eeles
16-May-2005

Purple Emperor - larva - Thatcham - 19-Jun-05 (4) [REARED]

Photo © Pete Eeles
19-Jun-2005

Purple Emperor - larva - Thatcham - 19-Jun-05 [REARED]

Photo © Pete Eeles
19-Jun-2005

Purple Emperor - larva - Thatcham - 20-May-04 (4) [REARED]

Photo © Pete Eeles
19-May-2004

Purple Emperor - larva - Thatcham - 20-May-04 [REARED]

Photo © Pete Eeles
19-May-2004

Purple Emperor - larva - Thatcham - 24-May-05 (5) [REARED]

Photo © Pete Eeles
24-May-2005

Purple Emperor - larva - Thatcham - 26-Jun-05 [REARED]

Photo © Pete Eeles
25-Jun-2005

Purple Emperor larva, final instar, near Arundel, 16 May 2007

Photo © Neil Hulme
16-May-2007

Purple Emperor larva, final instar, near Arundel, 25 May 2007

Photo © Neil Hulme
25-May-2007

Purple Emperor - larva - Thatcham - 03-Jun-10 (2) {REARED}

Photo © Pete Eeles
03-Jun-2010

Purple Emperor - larva - Thatcham - 03-Jun-10 (3) {REARED}

Photo © Pete Eeles
03-Jun-2010

Purple Emperor - larva - Thatcham - 03-Jun-10 (4) {REARED}

Photo © Pete Eeles
03-Jun-2010

Purple Emperor - larva - Thatcham - 03-Jun-10 (5) {REARED}

Photo © Pete Eeles
03-Jun-2010

Purple Emperor - larva - Thatcham - 03-Jun-10 (6) {REARED}

Photo © Pete Eeles
03-Jun-2010

Purple Emperor - larva - Thatcham - 04-Jun-10 (1) {REARED}

Photo © Pete Eeles
05-Jun-2010

Purple Emperor - larva - Thatcham - 20-May-11 (1) {REARED}

Photo © Pete Eeles

Purple Emperor - larva - Thatcham - 27-May-11 (1) {REARED}

Photo © Pete Eeles

Purple Emperor - larva - Thatcham - 18-Jun-13 (1) [REARED]

Photo © Pete Eeles
18-Jun-2013

Purple Emperor - larva - Thatcham - 18-Jun-13 (2) [REARED]

Photo © Pete Eeles
18-Jun-2013

Purple Emperor - larva - Thatcham - 15-May-14 [REARED]

Photo © Pete Eeles
15-May-2014

Photo Album ...


Pupa

The pupa is arguably the most difficult stage to find in the wild since, like the larva, it is perfectly disguised, matching the shades of green of the sallow leaf from which it is suspended upside-down, attached to the leaf by the cremaster. The pupa is a curious shape, being rather flattened so that, from the side, it looks plump whereas, from the back, it appears rather slim. This stage lasts around 2 weeks.

Purple Emperor - pupa - Thatcham - 19-Jun-05 (2) [REARED]

Photo © Pete Eeles
19-Jun-2005

Purple Emperor - pupa - Thatcham - 19-Jun-05 (5) [REARED]

Photo © Pete Eeles
19-Jun-2005

Purple Emperor - pupa - Thatcham - 19-Jun-05 (7) [REARED]

Photo © Pete Eeles
19-Jun-2005

Purple Emperor - pupa - Thatcham - 28-Jun-05 (2) [REARED]

Photo © Pete Eeles
03-Jul-2005

Purple Emperor pupa, near Arundel, 5 July 2007

Photo © Neil Hulme
05-Jul-2007

Purple Emperor - pupa - Thatcham - 01-Jun-11 (1) {REARED}

Photo © Pete Eeles

Purple Emperor - pupa - Thatcham - 27-May-11 (1) {REARED}

Photo © Pete Eeles

Purple Emperor - pupa - Thatcham - 27-May-11 (2) {REARED}

Photo © Pete Eeles

Purple Emperor - pupa - Thatcham - 07-Jun-14 [REARED]

Photo © Pete Eeles
07-Jun-2014

Purple Emperor - pupa - Thatcham - 13-Jun-14 [REARED]-2

Photo © Pete Eeles
13-Jun-2014

Purple Emperor - pupa - Thatcham - 13-Jun-14 [REARED]

Photo © Pete Eeles
13-Jun-2014

Purple Emperor pupa - Knepp Estate, Sussex 21-June-2016

Photo © Neil Hulme
21-Jun-2016

Purple Emperor pupa - Knepp Estate 3-July-2016

Photo © Neil Hulme
03-Jul-2016

Purple Emperor pupa (female) - Knepp Estate, Sussex 14-July-2016

Photo © Neil Hulme
14-Jul-2016

Photo Album ...


Aberrations

Description to be completed.

Click here to see the aberration descriptions and images for this species.

Similar Species

No similar species found.

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The following links provide additional information on this butterfly.

References

The species description provided here references the following publications:

ReferenceDetails
Boisduval (1840) Boisduval, J.A. (1840) Genera et index methodicus Europaeorum lepidopterum.
Fabricius (1807) Fabricius, J.C. (1807) Magazin für Insektenkunde, herausgegeben von Karl Illiger.
Lewin (1795) Lewin, W. (1795) The Papilios of Great Britain.
Linnaeus (1758) Linnaeus, C. (1758) Systema Naturae. Edition 10.
Morris (1853) Morris, Rev.F.O. (1853) A History of British Butterflies.
Petiver (1702-1706) Petiver, J. (1702-1706) Gazophylacii naturae et artis decas prima.
Rafinesque (1815) Rafinesque, C.S. (1815) Analyse de la nature ou Tableau de l'univers et des corps organisés.
Rennie (1832) Rennie, J. (1832) A conspectus of the butterflies and moths found in Britain, with their English and systematic names, times of appearances, sizes, colours, their caterpillars, and various localities.
Wilkes (1742) Wilkes, B. (1742) Twelve New Designs of English Butterflies.
Wilkes (1749) Wilkes, B. (1749) The English moths and butterflies: together with the plants, flowers and fruits whereon they feed, and are usually found.