Butterflies of the
Amazon and Andes
Family - NYMPHALIDAE
subfamily - DANAINAE
Tribe - ITHOMIINI
Thyridia psidii ino, Tingo Maria, Peru ©
The Ithomiini 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 Ithomiini 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.
Giant Glasswings, which have wingspans of about 90-100mm, include 7
Methona and a single species of
Thyridia. The 2 genera can be
distinguished by the position of the dark cross-bar on the hindwing,
which in Methona is further out from
the base. Thyridia also have shorter
antennae and in newly emerged specimens the hyaline areas have an
orange tinge, but this fades after a day or two and becomes similar
in hue to the creamy translucency of Methona.
subspecies Thyridia psidii ino is
distributed Ecuador to Peru and Bolivia. The Central American
subspecies melantho which is
distributed from Guatemala to Panama has much heavier black markings
on the forewings, and has orange-red hindwings in which there is a
prominent black spot at the end of the discal cell. There are
intermediate forms in Venezuela and elsewhere which are marked like
ino but have a translucent orange
Thyridia psidii inhabits disturbed
rainforest and cloudforest at altitudes between 0-1600m.
The egg is
large, globular and white. Females sometimes spend up to an hour
fluttering within a metre or two of the chosen oviposition site,
before finally laying an egg on the underside of a leaf.
When fully grown
the larva is translucent greenish-blue with yellow tubercles along
the sides of the abdominal segments. It feeds on
Cyphomandra ( Solanaceae ).
Thyridia psidii normally flies at a
height of 3 metres or more above ground level. Males are active mainly
in the mornings, but females can be seen gently floating across narrow
in the forest during the middle of the day. The butterflies are nearly
always seen singly.
Both sexes visit
Inga and Carica
flowers for nectar.