Butterflies of
Thailand, Malaysia &
Borneo
Lesser Dart
Potanthus omaha
EDWARDS, 1863
Family - HESPERIIDAE
subfamily -
HESPERIINAE
Tribe -
TARACTROCERIINI
introduction
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habitats |
lifecycle |
adult behaviour
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Potanthus omaha omaha,
Gopeng,
West Malaysia |
Introduction
The Hesperiinae are a vast subfamily, characterised by their
wide heads, large eyes, thick bodies, and their habit of basking
with their forewings held at a 45° angle, and hindwings held
horizontally. The caterpillars of all species feed on
monocotyledons - grasses, palms, orchids etc.
There are about
400 Hesperiinae in the Oriental region, of which 182 have so far
been recorded from peninsular Malaysia. Among these there are
dozens from the genera Salanoemia,
Telicota,
Taractrocera, Potanthus and
Oriens which share a similar
upperside pattern of broad yellowish-orange streaks on a dark
brown ground colour. Distinguishing these genera, and the
numerous species within them, relies on close examination of the
configuration of the markings on both wing surfaces, and
reference to text keys and diagrams.
The genus
Potanthus comprises of about 40
species, many of which are so similar that identification is
only possible after dissecting and microscopically examining the
genitalia.
Potanthus omaha
is the commonest member of the genus in peninsular Malaysia. It
also occurs in Myanmar, Thailand, Singapore, Sumatra, Borneo,
Sulawesi, Java and the Philippines.
Habitats
This species is found in disturbed grassy habitats at altitudes
between sea level and about 200m.
Lifecycle
Amazingly, for
such a common group of butterflies, virtually nothing is known
about the lifecycle of the Potanthus
species. The only species about which I have been able to find
data regarding the early stages are
confucius and serina,
details of which are given below, and are probably relevant to
omaha :
The larva of
confucius when fully grown is pale
translucent green, with a suffused dark green dorsal line, and a
dark brown head with chestnut cheek-stripes. It feeds on bamboo
Bambusa ( Poaceae ). It lives
within a shelter constructed by folding a leaf of the foodplant
into a tube, which is fastened with a few strands of silk. The
chrysalis is formed within the larval shelter. It is white and
glossy, with a yellowish thorax and pink eyes.
The egg of
serina is dome-shaped, smooth and
off-white in colour. It is laid singly on the leaves of
whip-leaf Flagellaria (
Flagellariaceae ). The larva lives within a shelter much like
that of confucius, and when young
is yellowish green, with a shiny black head. When fully grown it
is pale translucent green with a faint suffused dark dorsal
stripe, and a black head with broad whitish cheek-stripes. The
chrysalis is formed within the larval shelter and is pale
chestnut brown in colour.
Adult behaviour
Potanthus omaha is an active
sun-loving little butterfly which darts from flower to flower to
seek nectar. It normally basks in the characteristic Hesperiine
posture, with the forewings held at 45° and the hindwings in a
horizontal plane.
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