Butterflies of the Amazon and Andes
Family - NYMPHALIDAE
subfamily - DANAINAE
Tribe - DANAINI
subtribe - DANAINA
Danaus plexippus - North American
© Frank Model
Monarch is the most famous migrant in the butterfly world. Its
powers of migration are so great that it has been able to spread to
across the Americas from Canada to Peru; across the Atlantic to
Europe, Africa and India; and across the Pacific to Australia, New
Zealand and Papua New Guinea. A detailed discussion of its migratory
behaviour can be found on the
Monarch migration page.
Monarch has established 5 non-migratory subspecies in the neotropical
region - portoricensis in Puerto Rico;
leucogyne on the Virgin Islands;
megalippe in Cuba, the Bahamas and the
Caymans; tobagi on Tobago, and
nigrippus in the Andes.
Andean subspecies nigrippus differs from
the illustrated plexippus in several
ways. In nigrippus the ground colour is a
darker and duller brown; the upper half of the fw cell is black; the
diagonal band of sub-apical spots are white instead of pale brown; and
the black lines along the veins are heavier. The forewing shape in
nigrippus also tends to be less
Danaus plexippus nigrippus is found on
both sides of the Andes from Colombia to central Peru.
Ecuador the butterfly is mainly associated with severely disturbed
areas of mid-elevation forest in the western Andes. In Peru I have
found it mainly in valleys and gorges in the eastern Andes.
straw-coloured egg is barrel-shaped, with vertical keels, each of
which is linked by numerous small horizontal ridges. It is laid
singly on the underside of Asclepias
leaves, and also occasionally on Calotropis
( Apocynaceae ). The mature larva is white, with each segment marked
with narrow black and yellow bands. The 2nd thoracic segment and 8th
abdominal segment each bear a pair of black whip-like protuberances.
The larval foodplants contain toxins which can induce cardiac arrest
in small vertebrates. The toxins are sequestered by the larvae and
inherited by the adult butterflies which utilize them for defence
against insectivorous birds and reptiles. The pale green chrysalis
is plump and barrel-shaped, with the abdominal segments compressed.
At its widest point there is a narrow abdominal band studded with
yellow and black dots. It is suspended by a stout cremaster from
stems on or near the foodplants.
Danaus plexippus - final instar larva,
Santa Fe de Antioquoia, Colombia
© Adrian Hoskins
butterflies have a powerful but fluttering flight, interspersed with
periods of soaring and gliding in wide circles as they fly from one
clump of flowers to another. They settle frequently to nectar at
Asclepias and other flowers.
Courtship takes place in late morning at which time the male pursues
the female in flight, nudging and cajoling her until she settles,
typically on a bush, where copulation takes place.
bodies of all Danaines contain cardenolides derived from the larval
foodplants. Any bird eating one is likely to be affected by
vomiting, muscular spasms and visual disturbance. Birds are able to
learn and remember the patterns and colours of toxic butterflies, so
after suffering the unpleasant experience of eating one Monarch they
are less likely to attack another. Consequently many other species (
Mullerian mimics ) have evolved similar patterns and colouration
which help them evade predation. These mimics include a high number
of "tiger complex" orange and black Ithomiines as well as other
Danaines. Additionally numerous palatable species ( Batesian mimics
) have evolved similar colours and markings which fool birds into
believing that they are inedible.