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Butterflies of
the Amazon and Andes
Ticida Glasswing
Pteronymia ticida
HEWITSON, 1869
Family - NYMPHALIDAE
subfamily - DANAINAE
Tribe - ITHOMIINI
subtribe -
DIRCENNINI
Pteronymia ticida, Manu
cloudforest, 1700m, Peru
Introduction
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.
Ithomiines
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.
Ithomiines are
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.
There 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.
Most 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.
The
genus Pteronymia
contains 46 species, distributed variously from Mexico to Bolivia.
They are a diverse group with much variation in pattern and markings between
species, but can be recognised by the distinctive hindwing venation. The
yellowish suffusion at the base of the wings is a diagnostic feature
distinguishing ticida
from other Pteronymia.
The butterfly illustrated here was kindly identified by Ronald Brabant, an Ithomiine
specialist.
Pteronymia ticida
is found in Venezuela, Ecuador, Peru and Bolivia.
Pteronymia ticida, Manu
cloudforest, 1700m, Peru
Habitats
This species inhabits cloudforest habitats at altitudes
between about 1200-2000m.
Lifecycle
I do not have data
relating specifically to
ticida,
but the following applies in general to butterflies in the genus
Pteronymia
:
The
eggs are white. They are laid singly beneath the leaves of Solanaceae.
Females of most species return several times to the same plant, laying up to a
dozen eggs in total.
The
larvae of Pteronymia
species vary in appearance, some being dark along the back, with a pale central
stripe, while others are banded in black and white, and characterised by the
presence of a pair of soft fleshy horns projecting forward from the first
thoracic segment.
The
pupae of this genus are typically squat in shape, with compressed abdominal
segments, and a bulbous thoracic section. They are generally silver or gold in
colour, shiny, and resemble large raindrops hanging from stems or the undersides
of leaves.
Adult behaviour
Like
other Ithomiines, the butterflies spend long periods at rest on
the foliage of small shrubs in the darkness of their rainforest
and cloudforest habitats. They are extremely nervous, and if
disturbed fly immediately, only to resettle on another nearby
leaf. The flight is very slow, with characteristic deep wing
beats. When feeding in the open they behave very differently -
both sexes being very placid and reluctant to leave their flowers.
The
males of most Pteronymia species
pollinate Epidendrum orchids.
Males sequester pyrrolizidine alkaloids from
Heliotropium, Tournefourtia,
Myosotis ( Boraginaceae ), Eupatorium,
Neomiranda
and Senecio ( Asteraceae ). These
chemicals confer toxic qualities to the butterflies which deter
bird attacks. The chemicals are also used in the production of
pheromones. Often the males of several
Ithomiine species will gather together at communal leks, where they release
these pheromones from hair-like androconial scales on the leading
edge of their upperside hindwings. These attract more males, which
in turn release
further pheromones. After a few days the lek may include 50 or
more adults comprised of as many as dozen
different species. Passing females are attracted to the
leks by the complex fragrances. Their presence stimulates the
males to open their wings and release further pheromones that
entice them into copulation. Females obtain sustenance from
nectar, and also visit bird droppings which provide them with a
source of nitrogen that assists with the development of their
eggs.
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