Butterflies of
Thailand, Malaysia &
Borneo
Chestnut Bob
Iambrix salsala
MOORE, 1865
Family - HESPERIIDAE
subfamily -
HESPERIINAE
Tribe -
introduction
|
habitats |
lifecycle |
adult behaviour
|
 |
|
Iambrix salsala salsala,
Taman Negara,
West Malaysia |
Introduction
Iambrix salsala is one of only 2
members of the genus, and is found in India, Sri Lanka, Nepal,
Myanmar, Thailand, Laos, Vietnam, south China, Hong Kong, West
Malaysia, Singapore, Sumatra, Sabah, Sarawak, Brunei,
Kalimantan, Sulawesi and Java.
Its relative
I. stellifera is not found in India
or Sri Lanka but otherwise has a similar distribution. It
differs from salsala in the
configuration of the white spots on the underside.
Habitats
Iambrix salsala is commonly found
in open forested areas, along roadsides, and in village gardens
at elevations between sea level and about 600 metres.
Lifecycle
The eggs are dome-shaped and pink in colour, heavily dappled
with reddish brown. They are laid singly on the upper surface of
leaves of the foodplants which include bristlegrass
Setaria barbata, cow grass
Axonopus, and bamboo
Bambusa. They have also been
reportedly found on Mimosa but this
record must be regarded as highly dubious as this is a legume (
Fabaceae ), and caterpillars of Hesperiinae always feed on
monocotyledons - grasses, palms, bamboos, orchids, irises etc.
Immediately
after hatching the larva is bright orange with a black head, but
it soon changes to a shiny translucent yellowish-green colour.
In later instars it is pale green, peppered with dark green, and
has a pair of dark green lines along its back. The thoracic
segments are reduced in diameter, giving the impression or a
narrow "neck". The head is light brown with broad chestnut brown
stripes on the cheeks.
Throughout its
life the larva lives solitarily within a shelter constructed
from a grass blade that is rolled into a tube and fastened with
strands of silk. It rests within the tube by day, only venturing
out at night to feed, or when it needs to construct a new
shelter.
The chrysalis
is also formed within a grass tube, and is straw coloured, with
pink eyes. The tip of the proboscis projects beyond the wing
cases.
Adult behaviour
Both sexes visit flowers for nectar, and usually hold their
wings slightly apart while feeding.
They can also commonly be seen at rest on grasses or low
herbage, with their wings held erect. In hazy conditions when
temperatures are lower they bask in the characteristic
Hesperiine posture, with the forewings held at 45° and the
hindwings held horizontally.
|
