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.
Habitats
This species 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.