Thailand, Malaysia &
de Nicéville's Grass
Family - PIERIDAE
subfamily - COLIADINAE
The Grass Yellows
are all fairly small butterflies, readily recognised by their bright
yellow wings and their habit of gathering in small groups on patches
of damp sand or soil. Despite their name, none of their caterpillars
feed on grasses - the name is derived from the fact that most
species are found in disturbed grassy habitats.
Grass Yellows are among the most familiar of
tropical butterflies, with a total of 70 known species worldwide, of
which 36 are found in the Neotropical region, 13 in North America (
including Mexico ), 10 in Africa, 25 in the Oriental region and 10
in Australia / Papua New Guinea. Many of the species are migratory
in behaviour, with the ranges of several such as
hecabe overlapping into in 2 or more of
the zoogeographical regions.
There are 9 species
in peninsular Malaysia, most of which also occur in neighbouring
Thailand, and on Borneo and Sumatra. The commonest member of the
genus is hecabe, but none except
senna are rare, although
tilaha tend to be localised in distribution.
Eurema simulatrix is found in Sikkim,
Myanmar, Thailand, Laos, West Malaysia, Singapore, Palawan &
Mindanao ( Philippines ), Sumatra, Sabah, Brunei, Sarawak,
Kalimantan, Sulawesi, Java and on many of the smaller islands in the
This species is found in secondary or disturbed
habitats including forest clearings, along roadsides and riverbanks,
and in parks and gardens at elevations between 0-800m.
The lifecycle appears to be unrecorded, but it is
possible to make educated guesses :
The eggs of
Eurema species are always
spindle-shaped, and pale yellow or straw coloured when first laid,
changing to a darker shade before hatching. They are laid singly on
the upperside of leaves of the foodplants.
The foodplants of
simulatrix are not recorded. Other
Oriental Eurema species are known to
feed on Caesalpinia,
Cassia, ( Caesalpiniaceae ),
Pithecellobium ( Mimosaceae ) and
Wagatea ( Fabaceae ).
The caterpillars of
Eurema species when first hatched are
typically green, cylindrical, and covered in tiny tubercules from
each of which arises a single long stiff hair. In later instars the
hairs ( setae ) become progressively shorter. The fully grown larva
in most Eurema species is dull green
with a thin dark dorsal stripe, and a broader cream lateral stripe
below the spiracles. Each segment of the body is ribbed vertically,
and covered in small tubercules, giving it a rough textured
The chrysalis will
be shaped similarly to that of other members of the Coliadinae -
slim, sharply pointed at head and tail, and with prominent wing
cases. It is likely to be pale green or straw coloured, and probably
marked with fine blackish speckling.
Males congregate to
imbibe mineralised moisture
from damp sandbanks, usually in groups of less than a dozen, unlike
hecabe which gathers in scores.
E. simulatrix also tends to be found in
mixed aggregations which often include other Pierines such as
Appias, Papilionids such as
Graphium, and Nymphalids such as
Females are more
discreet in behaviour, normally being seen singly when nectaring.
They will visit many different flowers, but generally seem to prefer
smaller less conspicuous species.
Eurema simulatrix tecmessa,
Taman Negara, West Malaysia ©