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Butterflies of
the Amazon and Andes
Giant Glasswing
Methona confusa
BUTLER, 1873
Family - NYMPHALIDAE
subfamily -
DANAINAE
Tribe - ITHOMIINI
subtribe -
MECHANITINA
introduction
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habitats |
lifecycle |
adult behaviour
Methona confusa male, Madre de
Dios, Peru
Introduction
The
Giant Glasswings, which have wingspans of about 90-100mm, include 7 species of
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 is noted for having shorter
antennae, and a more squarish hyaline window occupying the basal half of the
hindwings.
Habitats
Methona are primarily lowland butterflies, found in
wet rainforest at altitudes between about 200-700m above sea level.
They are
usually encountered singly or in two's and three's,
at light
gaps in the denser parts of the interior.
Lifecycle
In Peru, in the late dry
season, I observed a female
Methona confusa
ovipositing on an unidentified species of Solanaceae growing at the edge of a
narrow forest track. The butterfly spent several minutes fluttering from leaf to
leaf, "tasting" the leaves with it's feet to determine the suitability of the
plant. It eventually laid a single egg, which was large, globular, white and
glistening, on the underside of a leaf.
Methona
confusa,
Madre de Dios, Peru
Adult behaviour
Shortly after dawn both sexes
undertake short migrations. They can often be seen at this time
flying across rivers - e.g. I have observed this several times on
the Rio Madre de Dios, Peru, in August and September ( late dry
season ). During these flights they periodically pause to spend a
few minutes nectaring at herbaceous plants on riverbanks or in
forest glades.
Later in the morning as
temperatures rise they retire to within the forest. Males are
often seen at light gaps where fallen trees
have opened the canopy and allow shafts of sunlight to penetrate
to the forest floor. In such areas they perch on foliage,
typically at heights between 2 - 3 metres, to await passing
females.
I have never
observed the pre-nuptial ritual, if one exists, but have found
copulated pairs settled on low foliage at about midday. If disturbed
they fly in tandem and resettle on higher foliage.
Females are
active mainly in the late afternoon, when they slowly and very
deliberately flit about from leaf to
leaf searching for oviposition sites.
Both sexes settle
with wings closed, but I have sometimes observed males slowly
fanning their wings, possibly as a means of disseminating
pheromones.
Towards the end
of the dry season, the butterflies aggregate in the company of
various other Ithomiine species, at dry riverbeds, where they
gather at the remaining damp areas. At these times the butterflies
can often be found around the base of palms, where they hide
amongst the tent of rootlets.
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