Butterflies of the
Amazon and Andes
Family - NYMPHALIDAE
Tribe - LIMENITIDINI
Adelpha boreas, male, Manu cloudforest,
900m, Madre de Dios, Peru
© Adrian Hoskins
are colloquially known as "Sisters". In terms of appearance they are
reminiscent of the White Admirals ( Limenitis
) of Eurasia, and share with them a fondness for flitting gracefully
around the lower branches of trees in the dappled sunlight of the
There are 85 known species of
Adelpha, all except two of which are
confined to Central and South America. They are characterised by the
distinctive black marbled pattern overlaid on a dark brown ground
colour; and by having a broad orange or white band on the forewings.
In the vast majority of species this band also extends vertically
down to the tornus of the hindwings.
While it is easy to
recognise the genus, determining the individual species can
sometimes be very difficult - a problem exacerbated by misidentified
museum specimens and mislabelled illustrations in many entomological
books. The only reliable identification resource is "The genus
Adelpha" by Keith Willmott. Accurate identification requires
meticulous examination of the configuration of the orange markings
in the subapical area on the forewing, and of the precise shape of
the vertical bands. It is also essential in most cases to examine
the patterning on the underside.
Adelpha boreas can
be confused with several other species including
ximena, irmina and
salus. These species are distinguished
from one another by close examination of the pattern formed by the
orange band on the forewings, and by differences in the underside
Adelpha boreas is a
widespread species found from Costa Rica to Bolivia.
This species occurs in primary and disturbed rainforest and
cloudforest habitats at altitudes between about 200-1200m.
The egg is white, and is laid singly on leaves of
Satyria ( Ericaceae ). The young larva
nibbles away at the tip of a leaf, leaving the midrib projecting. It
constructs a chain of frass along the midrib and rests at the end of
it. Frass chains appear to act as a deterrent to ants, spiders and
parasitoids who it difficult to walk on them. The fully grown larva
is disguised as a mossy twig, being mottled green and brown, and
covered with small whorled spines.
species is usually encountered as solitary males, seen flitting and
gliding in sunny areas in the vicinity of waterfalls and streams. The
butterflies periodically alight to imbibe moisture from damp ground,
and usually feed with wings outspread or half open.