Butterflies of
temperate Asia
Lesser Purple Emperor
Apatura ilia
DENIS &
SCHIFFERMÜLLER, 1775
Family - NYMPHALIDAE
subfamily -
APATURINAE
Tribe - APATURINI
Apatura ilia praeclara,
Anisimokva, Ussuri, Russian Far East
© J. Michel
Introduction
The genus
Apatura comprises of 4 species, 2 of
which - iris and
ilia, have a widespread distribution
covering most of Europe and temperate Asia. The other 2 species
are metis which is found in
south-east Europe, Kazakhstan and s.w. Siberia; and
laverna from n.e. China.
Apatura are closely related to the
South American genus Doxocopa, and in
common with them are sexually dimorphic - the males possessing a
beautiful purple sheen that is lacking in the females.
Apatura ilia has an almost unbroken
range stretching from northern Portugal to Siberia, Ussuri and
Japan. There are several alleged subspecies, each of which
produces a range of colour forms, but the degree of overlap of the
various forms suggests that these may be more attributable to
climate or habitat-controlled variation rather than to genetic
differences.
Apatura ilia yunnana, Yunnan, China
© Jean-Marc Gayman
Habitats
This species is found in damp deciduous woodlands, forests and
river valleys at altitudes between sea level and about 600m.
Lifecycle
In cooler localities there is a single generation per year
emerging in June. It is bivoltine in the warmer southern part of
it's range, producing a second brood of adults in August /
September.
The eggs are laid singly on the upperside of leaves of poplar
trees ( Populus sp ) and less often
on sallow ( Salix ). The larva (
except that of the 1st bivoltine generation ) hibernates when
young, either on the upper surface of a leaf which it has silked
to prevent it from becoming detached from it's twig; or in the
fork of a narrow branch. When mature the larva is pale green,
marked with pale diagonal lines on the sides, and is incredibly
well camouflaged when at rest on sallow or poplar leaves. The pupa
is equally well camouflaged, and is suspended from beneath a leaf.
Adult behaviour
Males, like those of its larger relative
iris, are well known for their habit of descending from the
trees to feed at unsavoury substances including faeces and
carrion.
They obtain vital salts from these substances, which are
passed to the females during copulation, and are possibly
essential for the production of fertile eggs.
Females are seen much less commonly,
and usually encountered when ovipositing on the lower foliage of
the foodplants. They are rarely seen feeding, and probably obtain
most of their nourishment from honey-dew ( aphid secretions which
coat the upper surface of leaves ).
Both sexes, like those of all
Apatura species, migrate to hill-tops
or ridges ( or in the case of lowland colonies to the tallest
trees in the vicinity ), where courtship and copulation take
place.
After copulation they return to the
valleys, where the females tend to oviposit mainly on trees
growing along the edges of forest roads and sunlit rides. The
males meanwhile "refuel" on fluids exuding from dug and carrion,
or from tree sap, prior to seeking a second or third female with
which to mate.
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