Butterflies of the
Amazon and Andes
Family - NYMPHALIDAE
subfamily - DANAINAE
Tribe - ITHOMIINI
Napeogenes glycera polymela,
Rio Kosnipata, 1500m, Peru ©
The Ithomiinae comprises of 376 known species,
although it is likely that at least another 30 will be discovered in
the near future. All are confined to the neotropical region.
are unpalatable to birds, and are consequently mimicked in
appearance by many other species. These include other unpalatable
species ( Müllerian mimics ), not only from the Ithomiinae but also
from several other butterfly families. There are also a large number
of edible species ( Batesian mimics ) which have evolved similar
patterns. Birds have the ability to memorise butterfly patterns and
so learn to avoid eating noxious species, but are also fooled into
ignoring similarly marked edible species.
characterised by having small eyes, slender abdomens and long
drooping antennae that lack distinct clubs. Males have a plume of
long androconial scales or "hair pencils" on the costa of their
hindwings. These are hidden from view when the butterflies are at
rest, but are displayed when the wings are held open during
courtship. Other Ithomiine characteristics include a very slow and
deep wing beat, and a preference for inhabiting the darkest recesses
of the forest understorey.
are basically 2 types of Ithomiine. The first type are the black and
orange-banded "tigers", many of which are mimicked by other species
due to their unpalatability to birds. The second type are the
"glasswings", recognised by their transparent or translucent wings,
prominent veins, and orange wing margins. Many genera contain
examples of both of these types, and in some cases an individual
species may produce adults of both forms according to location.
novices find the Ithomiinae very difficult to identify. Using only
the patterns to identify species is very unreliable because there
are so many similar species. Also many species produce a variety of
different colour forms according to locality and season. The best
approach therefore is to use the hindwing venation and other
anatomical features to identify the genus, and to then look at the
wing patterns to short-list the likely species.
Napeogenes contains 22 known species of
small to medium sized Ithomiines. Some such as
tolosa and duessa are marked
with large patches of orange and cream on a black ground colour,
while others, including glycera,
harbona fall into the "Glasswing" category, with largely
transparent wings, marked on the under surface with orange and
black, and a series of white submarginal spots.
occurs in Ecuador, Peru and Bolivia.
This is a mid-elevation rainforest and cloudforest species found at
altitudes between 600-1800m.
The eggs are white, and laid singly on the underside of leaves of
Solanum ( Solanaceae ).
Males gather in two's and three's
in light gaps, where they feed at pyrrolizidine alkaloids, chemicals
which are exuded by decomposing leaves, flowers and stems. These
chemicals are converted by the butterflies into defensive toxins, and
into pheromones that are used to entice mates.
butterfly in the photograph above is feeding from the decomposing
corpse of an insect which is trapped in a spider web. Females also
feed at flower nectar, and at bird droppings.