Common Butterflies of Sri Lanka

T
LC
Chestnut Bob Iambrix salsala
Grass Demon Udaspes folus
S
LC
Hesperiidae
Male
Male
The male is completely chestnut coloured on the upper side without any markings.
The female is the same colour, but has a distal band of white spots on the forewing.
The number of spots is variable. Its underside is also chestnut in colour in both sexes,
except for the hidden area of the forewing which is dark brown. Usually the male
has one or two very small white spots on both wings. The female has more patches
and they are bigger than those of the male. Again the number of spots varies. Its
abdomen, thorax, head and legs also take on the shades of chestnut.
Though its flight is jerky, it is not fast as bigger Hesperiids. It basks in the morning by
keeping its hind wing spread flat and its forewing perpendicularly. They are fond of
feeding on flowers of herbs among grasses. They come out in the morning and the
evening. During the mid-day hours they fly under dappled sun light.
It is found in all habitats with short grasses but is reduced in numbers in vast open
areas. It is common amidst roadside vegetation which has shady trees nearby.
LFPs: Various grasses including Axonopus compressus (f.dx ;Kfld,), Ochlandra
stridula (ng) and Oryza sativa (f.dhï).
The sexes are alike. The upper side is dark brown. It has scattered white patches on
the forewing which are smaller in the distal parts than in the basal part. The hind wing
has a large white patch on the centre. The underside is dark reddish brown which is
somewhat obscured by the pure white scales that cover most of the hind wing. The
margin of this white scaling continues up to its snout along the thorax and eye in the
form of a straight line. The forewing is also slightly washed with white scales interior
to the sub-margin. The white patches are the same as on the upper side. The dorsal
area of its abdomen, thorax and head are dark brown.
It has quite a rapid flight, but is distinct due to its pied colouration. When it settles, its
wings appear to rotate around a hinge at its thorax. It is active at dawn and dusk, and
in gloomy conditions. It feeds on the nectar of flowers that have long corolla tubes
such as Tabernaemontana divaricata (j;=iqoao) which are inaccessible to other species.
While it was considered a very rare butterfly in 1950s, it is now commonly seen around
home gardens.
LFPs: Zingiberaceae plants including Kaempferia galanga (ysÕ=re msh,s), Curcuma
longa (ly), Curcuma zedoaria (wrkaly).
Clearing the
proboscis by its
own leg
Hesperiidae
130 Common Butterflies of Sri Lanka
Common Butterflies of Sri Lanka 131