Monarch

Danaus plexippus (DAN-ee-us PLEK-see-puss)

Monarch - imago - Thatcham - 25-Sep-06 (0759) [REARED]
Photo © Pete Eeles
 

Wingspan
95 - 100mm

Checklist Number
59.001

Family:NymphalidaeRafinesque, 1815
Subfamily:DanainaeBoisduval, 1833
Tribe:DanainiBoisduval, 1833
Genus:DanausKluk, 1780
Subgenus:  
Species:plexippus(Linnaeus, 1758)

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Introduction

This species is the largest butterfly seen in the British Isles, and is also one of our rarest migrants. This butterfly is known for its ability to migrate across large distances. The migrations in north America are one of the greatest natural phenomena in the world - where the adult butterflies can migrate from as far north as Canada to the overwintering grounds in very specific sites in Mexico, the west coast of California and Florida. The first record of this species in the British Isles, by a schoolboy, was on 6th September 1876 in Neath in south Wales. Although initial records were thought to be the result of accidental transportation by ship, subsequent years, such as 1933 when 40 individuals were caught, meant that this theory was dismissed and that the most-likely cause was a genuine immigration.

The total number of records for the British Isles is less than 500. The most-recent major migration was in 1981 with 135 sightings. Many north American bird species were also recorded that year. However, there is still some question as to the true origin of this immigration since the species is also known from Madeira, southern Spain, Portugal and the Canary Islands, which it reached in 1860 and survives using Asclepias curassavica as its foodplant.

The larva feeds on various Milkweeds (Asclepias species) which are not native to the British Isles, and this explains why the immature stages have not been found in the British Isles. However, in August 1981, a Monarch that had escaped from a nearby butterfly farm was seen to lay on Milkweeds in Kew Gardens. Some of the eggs were collected and reared indoors, where the first adult emerged just one month after the egg had been laid. This species is a rare migrant to the British Isles. Although there are records from many areas, sightings are concentrated in the south and west of both England and Ireland. There is a particular concentration in Cornwall and the Scilly Isles.

Danaus plexippus

This species was first defined in Linnaeus (1758) as shown here (type locality: North America).

Monarch - imago - Thatcham - 25-Sep-06 (0759) [REARED]

Male
Photo © Pete Eeles

Monarch - imago - Thatcham - 25-Sep-06 (0753) [REARED]

Male Underside
Photo © Pete Eeles

Monarch - imago - Thatcham - 30-Sep-06 (0783) [REARED]

Female
Photo © Pete Eeles

Monarch - imago - Thatcham - 25-Sep-06 (0758) [REARED]

Female Underside
Photo © Pete Eeles

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
1832ArchippusBrown (1832)
1901MonarchKirby (1906)
1906MilkweedSouth (1906)
1913Black-veined BrownNewman & Leeds (1913)

Conservation Status

No conservation action is relevant for this species.

Habitat

Description to be completed.

Distribution

1.2 Rare Migrant
 

This species is a rare migrant to the British Isles.

Life Cycle

Although sightings have been recorded from March to November in the British Isles, the peak is in September and October. These latter months correlate with the southward migration in north America and it is not unreasonable to believe that favourable winds have pushed some individuals across the Atlantic. Unfortunately, this spectacular insect is unable to survive our winter.

Imago

The male butterfly is distinguished from the female by having less prominent black markings to the veins and conspicuous sex brands on the upperside of the hindwings.

Description to be completed.

Danaus plexippus

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (9)

Photo © Pete Eeles
07-Feb-2009

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (15)

Photo © Pete Eeles
07-Feb-2009

Monarch - imago - Thatcham - 25-Sep-06 (0756) [REARED]

Photo © Pete Eeles
24-Sep-2006

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (3)

Photo © Pete Eeles
07-Feb-2009

Monarch - Danaus plexippus - Naples Botanical Garden, Naples, Florida 20-Nov-2014

Photo © celery

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (16)

Photo © Pete Eeles
07-Feb-2009

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (10)

Photo © Pete Eeles
07-Feb-2009

Monarch - imago - Dominican Republic - 18-Aug-05

Photo © Pete Eeles
Dominican Republic
20-Aug-2005

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (11)

Photo © Pete Eeles
07-Feb-2009

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (2)

Photo © Pete Eeles
07-Feb-2009

One Monarch alighting on another. Local park, centre of Funchal, Madeira February 24th 2015.

Photo © Catteraxe
Madeira
24-Feb-2015

Monarch on the promenade walk in the main hotel area of Funchal, Madeira on February 22nd, 2015

Photo © Catteraxe
Madeira
22-Feb-2015

Monarch - imago - Thatcham - 04-Oct-04 (4) [REARED]

Photo © Pete Eeles
04-Oct-2004

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (17)

Photo © Pete Eeles
07-Feb-2009

Monarch - imago - Thatcham - 25-Sep-06 (0753) [REARED]

Photo © Pete Eeles
24-Sep-2006

Monarch pair - Gibraltar 27-March-2017

Photo © essexbuzzard

Monarch - imago - Santa Cruz, California, USA - 07-Feb-09 (13)

Photo © Pete Eeles
07-Feb-2009

Monarch - imago - Thatcham - 25-Sep-06 (0759) [REARED]

Photo © Pete Eeles
24-Sep-2006

Monarch - imago - Thatcham - 30-Sep-06 (0783) [REARED]

Photo © Pete Eeles
28-Sep-2006

Monarchs Mating (REARED)- Devon, 2013

Photo © Coopera

Photo Album (29 photos) ...


Ovum

Eggs are laid singly on the foodplant and this stage lasts only 3 or 4 days.

"The egg is conical in shape, closely resembling an acorn in form, but the apex is slightly more pointed; it is small in comparison with the large size of the butterfly, measuring only 1.3 mm. in height; there are from twenty to twenty-three longitudinal keels (the number varying in different specimens); about fourteen of these run the entire length from summit to base, the remainder commence about one-fourth from the apex and run to the base; it is ribbed transversely by about thirty-four (ribs), which extend over the whole surface, excepting the micropyle, which is reticulated with a network pattern. The colour when first laid is a very pale primrose-yellow, and remains unchanged until the third day, when it becomes pearl-white, mottled with yellow and leaden-coloured markings, which first indicate the development of the young larva; it gradually loses the yellow, and a crescent of leaden spots appears on the side denoting the dark feet, and the crown becomes wholly dark leaden colour from the black head showing clearly through the shell." - Frohawk (1924)

Monarch - ovum - Dominican Republic - 18-Aug-05

Photo © Pete Eeles
20-Aug-2005

Monarch - ovum - Unknown location - Unknown date [REARED] [Brian Clegg]

Photo © Brian Clegg

Monarch - ovum2 [William Zittrich]

Photo © William Zittrich
26-Dec-2008

Monarch - ovum [William Zittrich]

Photo © William Zittrich

Photo Album (4 photos) ...


Larva

The larva eats its eggshell on hatching before feeding on the leaves of the foodplant. The larvae are conspicuously marked, providing a warning to predators that the larva is poisonous, having built up toxins that it obtains from the foodplant. These poisons are passed on to the adult butterfly. Depending on temperature, this stage can be completed in as little as 16 days.

The primary larval foodplant is Milkweeds (various) (Asclepias spp.).

Monarch - larva - Unknown location - Unknown date [Brian Clegg]

Photo © Brian Clegg

Monarch - larva - Stratford-upon-Avon - 13-Jun-10 (2) {REARED}

Photo © Pete Eeles
13-Jun-2010

Monarch larva - Gibraltar 27-March-2017

Photo © essexbuzzard

Photo Album (3 photos) ...


1st Instar

"Immediately after emerging from the egg the larva eats the greater part of the shell, which forms its first meal, usually only leaving the base. It makes its exit by eating away the crown. At 5.30 a.m., August 12th, a young larva was observed feeding on its empty shell; when it had done it crawled away and found an unhatched egg close by, which it at once started to devour, biting through three of the keels, when it was stopped from doing more damage, and put on to a terminal leaf of Asclepias, upon which it immediately began feeding, and soon perforated the entire substance. Directly after emergence the larva measures 2.12 mm. long; the head is large, black and shining, with a few fine black hairs, the eye spots olive and mouth parts pearl-grey. The body gradually tapers to the posterior segment, which bears a dorsal olive-brown disc; on the second and eleventh segments are pairs of sub-dorsal olive-brown knobs, and a pair of transverse sub-dorsal discs on the first segment. Along the body are rows of black bristles, the tips terminate with extremely minute knobs, each bristle is set on an olive-coloured conical base; there are four above each spiracle on either side, and two below, making six in all, one dorsal, two sub-dorsal, one super-spiracular and two sub-spiracular; others are placed on the legs and claspers. The segments have four sub-divisions. The ground colour is pearly-grey, with a very slight yellowish tinge in shadows, or cobweb colour. The second sub-divisional wrinkle of each segment is light brown, forming a band which gives a ringed appearance to the larva. The surface is covered with minute black granulations; the legs are black, the claspers olive-black and pearly-ochreous. Before the first moult it measures 4.8 mm. long; the ground colour is pearly-ochreous-white, with a black stripe encircling each segment." - Frohawk (1924)

2nd Instar

"The first larva, which hatched 5.30 a.m., August 12th, moulted first time 6 p.m., August 16th, being four and a half days in the first stage. Before the second moult it measures 8 mm. in length. The head is now similar in colouration to the subsequent stages, being pale yellow, striped with black. The posterior sub-division of each segment is lemon-yellow; each segment is encircled with a black band; the sub-dorsal knobs are developed into short tubercles." - Frohawk (1924)

3rd Instar

"One which moulted the first time on the evening of June 8th, 1910, fed at frequent intervals during both day and night in its second stage, and fixed for its second moult on the morning of June 10th, and moulted the following morning, remaining only two and a half days in the second stage. The one which moulted first time August 16th, 1911, moulted the second time on August 19th. Another, which hatched 6 a.m., August 12th, moulted first time August 15th, and the second time on the 18th. Before third moult it measures 12.7 mm.; all the markings of the subsequent stages are now visible. The larva which moulted the second time June 11th, 1911, fixed itself for the third moult morning, June 13th, and moulted the third time early morning of the 14th." - Frohawk (1924)

4th Instar

"After the third moult it is 19 mm. long. In all respects it is similar in both colouring and pattern to the fully grown larva. The anterior tentacles now measure 3.5 mm. long. Shortly before fourth moult it measures 22.2 mm. to 25.4 mm. in length; the anterior tentacles now attain 6.35 mm. long. All the colours are clear and defined." - Frohawk (1924)

5th Instar

"The fourth moult took place midnight, June 18th. The first meal after moulting consisted of its cast skin. After the fourth and last moult, fully grown, the larva measures 56 mm. in length. The body is of uniform thickness, excepting the rather tapering first and last segments. The head is yellow with three transverse, black, hoop-like bands; the central one above the mouth is united below; the surface is sprinkled with minute fine black hairs. On each side of the second segment is a long sub-dorsal, fleshy, velvety black tentacle, very slender and cylindrical, densely clothed with extremely minute points and sparsely sprinkled with fine black hairs. These organs project over the head, are slightly upturned and widely divergent at the tips; while feeding they are kept in constant motion, generally jerked quickly to and fro. On the eleventh segment is a much shorter pair of similar structure. The ground colour of the body is pale lemon-yellow and white; the white forms a broad median band round each segment; the segments are striped and banded with velvety steel-black; the stripes, two in number, on each segment, from the fourth to tenth inclusive, reach over the dorsal surface down to the spiracle and separate the white from the yellow, one anterior and one at the posterior third; between this and the segmental division is a short transverse dorsal streak; midway between the two larger stripes is a band of the same velvety texture completely encircling the body and enclosing the spiracle, which is also black; above the clasper is a black oblique mark. The black bands extend over the frontal half of each leg and clasper, the posterior half white; the feet of both legs and claspers are shining black. The segmental divisions are broadly black ventrally, tapering to a thin streak dorsally. The entire surface is sparsely sprinkled with extremely small clubbed bristles with dark bulbous bases; these are only visible under microscopic power. The larvae appear of very docile temperament, as they take but little notice of being disturbed, and if touched while feeding they merely stop for a few seconds and then continue, and are quite content to feed in any attitude they may be placed in; their only object is to be almost continually feeding, consequently they rapidly grow. The larva described which moulted midnight, June 18th, became fully grown and stopped feeding on the evening of June 23rd; it spun up, attaching itself by its anal claspers to a pad of silk spun on the leaf stalk, on the following morning, and pupated the next morning, June 25th. Another fully grown larva ceased feeding on June 8th; after roaming about for six hours it spun a silk pad on the gauze covering and suspended itself, and pupated the following evening, June 9th. The next morning the colouring of the pupa had matured. The first two which hatched August 12th, 1911 , became fully grown and stopped feeding on the afternoon of August 26th, and roamed about for many hours. They both suspended themselves the following afternoon, and pupated the next afternoon, August 28th, having remained in the larval state sixteen days." - Frohawk (1924)

Monarch - larva - Unknown location - Unknown date (2) [Brian Clegg]

Photo © Brian Clegg

Monarch - larva3 [William Zittrich]

Photo © William Zittrich
28-Dec-2008

Monarch - larva4 [William Zittrich]

Photo © William Zittrich

Monarch - larva5 [William Zittrich]

Photo © William Zittrich
05-Jan-2009

Monarch - larva [William Zittrich]

Photo © William Zittrich
28-Dec-2008

Monarch - larva2 [William Zittrich]

Photo © William Zittrich

Monarch - larva - Stratford-upon-Avon - 13-Jun-10 (1) {REARED}

Photo © Pete Eeles
13-Jun-2010

Monarch - larva - Stratford-upon-Avon - 13-Jun-10 (3) {REARED}

Photo © Pete Eeles
13-Jun-2010

Monarch - larva - Thatcham - 20-Jul-14 [REARED]-3

Photo © Pete Eeles
20-Jul-2014

Monarch - larva - Thatcham - 20-Jul-14 [REARED]-4

Photo © Pete Eeles
20-Jul-2014

Monarch - larva - Thatcham - 20-Jul-14 [REARED]

Photo © Pete Eeles
20-Jul-2014

Photo Album (11 photos) ...


Pupa

The pupa hangs head-down from a stem or leaf, attached by its cremaster. This stage lasts around 2 weeks.

"The pupa measures 25.4 mm. long, including the cremaster, and is 12.7 mm. wide across the middle of the abdomen; it is proportionately stout for its length, rounded and remarkably smooth, having no angles or projections. The abdomen is conical and terminates in a stalk-like cremastral process, the whole form producing a beautiful pendant object, especially when viewed either dorsally or ventrally, and from its smoothness, colouring and general structure it resembles a finely modelled jade ornament, encircled and studded with highly burnished gold, rather than a living object. Lateral view: Head blunt and slightly rounded, forming a continuous curve with the meso-thorax; the meta-thorax and first three abdominal segments form a straight, inclined line, the abdomen then curving to apex, which terminates in a long, shining black cremaster, amply furnished with a cluster of black hooks at the extremity; the ventral surface of the abdomen is rounded, it then runs in a straight line from apex of wings to head. The posterior edge of the third abdominal segment is beautifully adorned by a dorsal belt reaching to the hind margin of the wings, the knobs of which are tri-coloured; the front edge is intensely black and shining, the hinder half of highly polished nacreous splendour, reflecting the intensely brilliant gilded band on which they are situated; there are six other equally brilliant gilded discs running in an oblique line on each side from the head to the posterior surface of the meso-thorax and one in the disc of the wing. In the centre of the anal segment is a medio-dorsal black spot, a pair of black points on the ventral surface, and two black markings running from the cremastcr; the spiracles are slightly raised and whitish. The entire structural details are very inconspicuously outlined; the abdominal segments, from the third, are very narrow, producing a stunted, rounded cone. The whole ground colour is a pale glaucous-green; for the first few hours after pupation the colour is a deeper, yellower green and the ornamentations opaque yellow. It is very firmly attached by the cremastral hooks to a small but dense pad of silk. The first one which pupated on June 9th, 1911, began to show signs of emergence on June 22nd by the thorax becoming changed to a duller leaden-green. It gradually turned duller all over, and finally became uniformly of a leaden hue, but the gold ornamentation still retaining the brilliancy, and the markings of the imago appeared on the morning of the 24th and it (a female) emerged at 3 p.m. that day, remaining fifteen days in the pupal state. The imago was fully developed in twenty minutes after emergence." - Frohawk (1924)

Monarch - pupa - Thatcham - 06-Oct-04 [REARED]

Photo © Pete Eeles
06-Oct-2004

Monarch - pupa - Thatcham - 25-Sep-06 (0748) [REARED]

Photo © Pete Eeles
24-Sep-2006

Monarch - pupa [William Zittrich]

Photo © William Zittrich

Monarch - pupa - Thatcham - 23-Jul-14 [REARED]

Photo © Pete Eeles
23-Jul-2014

Monarch Hatching - 12-Oct-14 [REARED]

Photo © Trik

Photo Album (5 photos) ...


Aberrations

Description to be completed.

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

Similar Species

No similar species found.

Videos


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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 (1833) Boisduval, J.A. (1833) Icones historiques des Lépidoptères d'Europe nouveaux.
Brown (1832) Brown, T. (1832) The book of butterflies, sphinxes and moths.
Frohawk (1924) Frohawk, F.W. (1924) The Natural History of British Butterflies.
Kirby (1906) Kirby, W.E. (1906) Butterflies and Moths of the United Kingdom.
Kluk (1780) Kluk, K. (1780) Zwierzat domowych i dzikich osobliwie kraiowych historyi naturalney poczatki i gospodarstwo.
Linnaeus (1758) Linnaeus, C. (1758) Systema Naturae. Edition 10.
Newman & Leeds (1913) Newman, L.W. and Leeds, H.A. (1913) Text Book of British Butterflies and Moths.
Rafinesque (1815) Rafinesque, C.S. (1815) Analyse de la nature ou Tableau de l'univers et des corps organisés.
South (1906) South, R. (1906) The Butterflies Of The British Isles.