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monarch   <>   danaus plexippus   <>   bleachtfhéileacán

Family: Nymphalidae,  
: Dannidae

  Occasional as vagrant
mainly sighted in the south and southwest costal districts in Ireland

Septenber and October
No natural breeding habitat in  Ireland
Larval Food Plant:
   Milkweed Asclepias sp.
They do not survive Irish winters.

Males have a sex gland on each hindwing which distinguishes it from the female.
Females have broader black veins on wings (see below).

Highlights From  the Migration Trail                  




Life Cycle of  the Monarch

The pale green, ribbed and pitted egg measures approx. 1.2mm in height and hatches after c.4 days.
The female Monarch lays many eggs in a single day.  These eggs are laid singly usually on the underside of  a leaf 
near the top of the host plant.


The brightly coloured larvae measure approx. 5cm. in length and are off-white with black and yellow segmental 
stripes.  A pair of fine black filaments extend from both an upper thoracic and a lower abdominal segment.

   Feeding on Milkweed     © DHardiman 2002  

The young larvae first eat their eggshell and then begin feeding on the host plant.  As they feed on milkweed 
the larvae absorb a poison from the plant (cardiac glycoside) which they store and pass on to the adult butterfly 
making both poisonous to most vertebrates. 

Under favourable climatic conditions the entire larval stage lasts between 9-16 days.

Common Milkweed

Common Milkweed


The plump, smooth, jade-green pupae are studded with glistening gold as is the dorsal belt that adorns their 
3rd abdominal segment.

© DHardiman 2002  

 Pupae are attached, by black cremasteral hooks at the end of their long black shining cremaster, to a silken pad 
spun by the larvae on a stem or leaf of the food plant or on nearby vegetation.

   Black shining cremaster
                © DHardiman 2002

Just before Monarchs emerge from pupation, after c. 16 days (occasionally much longer), 
pigmentation of the scales develops and the wing pattern becomes visible through the pupal case.


Where resident all  Monarchs are sexually mature on emergence from pupation when they mate and reproduce
after 4-5 days.  They feed upon nectar, water and sometimes liquids from decaying vegetation and survive for
up to 6 weeks.




Monarch  Range:

Resident in the following countries:


     Most Islands between Australia and Taihiti

     South America ~  Most Monarchs of  S America are a different sub-species (D. plexippus erippus)  
                                    to those seen in N America (D. plexippus plexippus)
     Southern California

     Hawaii and several other Pacific Islands

     Caribbean Islands ~ both species and sub-species are sometimes found
     Costal districts of  Canary Islands

     Costal districts of  Southern Spain


Occasional vagrants/migrants in the following countries or regions:



 SW  Portugal


       And more rarely:

 S Ireland

 SW England

 S France

*Annual Migration of  Monarchs to Central Mexico and S California from:

United States






Monarch Butterfly Update: April 19, 2012

 People are now seeing fresh-winged butterflies of the new generation. 

Meanwhile, the remaining monarchs from Mexico continue to travel and lay eggs.

Highlights From  the Migration Trail  




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 RedAdmiral ] PaintedLady ] CloudedYellow ] Comma ] [ Monarch ] 

Hesperidae ] Pieridae ] Lycaenidae ] Nymphalidae ] Satyridae ] Migrants ] .