Butterflies of
Thailand, Malaysia &
Borneo
Common
Dartlet
Oriens gola
MOORE, 1887
Family - HESPERIIDAE
subfamily -
HESPERIINAE
Tribe -
introduction
|
habitats |
lifecycle |
adult behaviour
|
 |
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Oriens
gola,
Bukit Tapah,
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.
In
Oriens the post-discal orange band
is united with the lower cell spot on the upperside forewing - a
feature which distinguishes them from
Telicota and Potanthus.
In
Malaysia there are 3 Oriens species
- gola, paragola and
goloides. On the underside
hindwings paragola has a dark brown
ground colour. In both gola and
goloides this is replaced by
yellow, peppered finely with black. These 2 species can be
distinguished by reference to the veins, which are dark in
goloides and yellow in
gola.
Oriens gola is found in India, Sri
Lanka, Myanmar, Thailand, Vietnam, peninsular Malaysia, Borneo
and Sumatra.
Habitats
This species is found in sunny glades and clearings in secondary
forest and plantations, and along roadsides, riverbanks and
other sheltered grassy habitats at elevations between sea level
and about 400 metes.
Lifecycle
The egg is dome-shaped, shiny and straw coloured. It is laid
singly on the upperside of leaves of the foodplants.
The caterpillar is whitish dorsally, suffusing into pale green
below the spiracles. The body segments are wrinkled vertically,
and densely covered with tiny tubercles, giving the skin a rough
texture. The head is pale yellowish-green, with a narrow black
diagonal stripe across each cheek. The foodplants according to
Corbet & Pendlebury are the grasses
Imperata and Paspalum (
Poaceae ).
The chrysalis
is formed within a tube constructed from a rolled grass blade.
It is a bright translucent green colour, with 3 thin white
stripes along the back. The eyes protrude slightly, and a white
spike projects from the head.
Adult behaviour
Both sexes can commonly be seen darting about in the sunshine in
grassy habitats, often settling on low herbage to rest, usually
keeping their wings held erect. In weak or hazy sunlight they
bask in the characteristic Hesperiine posture.
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