ButterflyCircle Plays Host to US Researcher

ButterflyCircle Plays Host
American Researcher Melissa Whitaker visits Singapore


Photo courtesy of Melissa Whitaker

Recently, ButterflyCircle members played host to visiting PhD student Melissa Whitaker from the University of California, Davis.  Melissa is on a Southeast Asian tour, visiting Indonesia, Malaysia, Singapore and Thailand on a quest for research material on myrmecophily (that's butterfly-ant association for us laymen!).  She stopped by Singapore for only a day, unfortunately. But in her own words, "it was the most fruitful trip so far!" 

ButterflyCircle members Khew SK and Horace Tan showed Melissa around the nature reserves in Singapore and she was able to observe, first-hand, some Lycaenidae caterpillars and their ant guardians. Melissa is on the final stretch of her thesis and is due to receive her Doctorate some time next year.   

Melissa recording notes of her caterpillar encounters at Mac Ritchie Nature Reserve

Melissa's research interest, as she mentions on her website is "following in a long tradition of using butterflies to explore questions in ecology and evolution. I am particularly interested in the evolution and ecology of positive species interactions, and am using ants and lycaenid butterflies as a model system."

A clutch of Flos caterpillars tended by ants (on Syzygium grande) that Horace pointed out to Melissa

After Singapore, Melissa heads for the Cameron Highlands in Malaysia, and then off to Koh Samui, Thailand to meet Les Day, another ButterflyCircle member. We wish Melissa all the best in her future endeavours and adventures in Southeast Asia, and hope that she will visit Singapore again and to share with us her knowledge of butterfly-ant relationships some time soon! 

Text & Photos by Khew SK

Reference : Melissa Whitaker's website

Random Gallery - Green Oakblue

Random Butterfly Gallery
The Green Oakblue (Arhopala eumolphus maxwelli)

Our random butterfly this week is the moderately rare Green Oakblue (Arhopala eumolphus maxwelli).  The species is so named because of the iridescent green upperside of the males. It is one of several species of Arhopalas with green uppersides in Singapore and Malaysia. This pristine male was shot by ButterflyCircle early stages expert, Horace Tan, in the heart of the nature reserves in Singapore. This individual appeared to be sunbathing to dry its wings. Horace explained that it was perched on the underside of a leaf that was exposed to the sun.

Life History of the Dark Flat

Life History of the Dark Flat (Tapena thwaitesi bornea)

Butterfly Biodata:
Genus: Tapena Moore, 1881
Species: thwaitesi Moore, 1881
Sub-Species: bornea, Evans, 1931
Wingspan of Adult Butterfly: 30-35mm
Caterpillar Local Host Plant: Dalbergia rostrata (Leguminosae).

A puddling male Dark Flat showing its wing underside.

A male Dark Flat perching on a leaf in the nature reserve.

Physical Description of Adult Butterfly:

Both wings are angulated at vein 3, more strongly so in the hindwing. Above, the male is dark brown with obscure dark and blotchy markings. In contrast, the female is paler brown with more prominent blotchy dark markings On the forewing, there are two (spaces 7-8) or three (in spaces 6-8)  small and hyaline subapical spots. The female has more hyaline spots in the base of spaces 2, 3 and 9, 10 in the forewing, and a hyaline spot near cell-end in the hindwing.  Underneath, the wings are similarly marked as per above. The male has a hair tuft on its hind tibiae.

The upperside of a female Dark Flat.

An animated sequence illustrating the hyalinity of the spots in the wings of a female Dark Flat.

Field Observations of Butterfly Behaviour:

Although C&P4 describes Dark Flat as being rare in the Malay peninsula, this species is only moderately rare in Singapore as there has been a good number of  sightings  made each year.  Its  distribution is restricted to the forested areas within the  Central catchment and Bukit Timah nature reserves. The adults are fast and strong flyers  and  have the habit of perching  with their wings opened flat. They are typically sighted when puddling on wet grounds in the nature reserve.

A Dark Flat puddling together with a Common Hedge Blue on a wet ground soiled with bird dropping.

Another puddling Dark Flat.

Early Stages:

At least two Dalbergia species have been recorded as the larval host for the Dark Flat. One of them has been identified as Dalbergia rostrata, a climber which can be found in several sites in the nature reserves.  The caterpillars of the Dark Flat feed on  leaves of the host plant. When not  feeding, the caterpillars seek safety and concealment in a leaf shelter formed by cutting and folding a leaf fragment along the edge of the leaf.

Local host plant: Dalbergia rostrata.

A partially eaten leaf of the host plant Dalbergia rostrata with a leaf shelter (center of picture).

The eggs of the Dark Flat are laid singly on the young shoot of  host plant. The rosy red egg is dome-shaped with a base diameter of about 0.75mm. There are a number of white longitudinal ridges running from near the top of the egg to the rim of the base. Some of these ridges originate from as far up as the micropylar whilst a few are rather short and end only a short distance from the top.

Two views of an egg of the Dark Flat.

Two views of a mature egg of the Dark Flat. Note the polar portion of the egg shell had already been nibbled away.

Two views of an empty egg shell of the Dark Flat.

The egg decolorises as it matures and takes about 3 days to hatch. The young caterpillar emerges by eating away the polar part of the egg shell. The rest of the egg shell is not eaten by the newly hatched which is about 2mm in length. At this stage, the  body is golden yellow in colour. It has very rather short setae on the body surface, and a small tuff of setae at the posterior end. The black head capsule is  heart-shaped. 

Two views of a newly hatched caterpillar, length: 2mm.

Top: Newly hatched caterpillar resting after making two cuts along the leaf edge. The cutting would resume later and continue until a flap of lamina can be folded over. Bottom: The finished leaf shelter one day later.

The newly hatched makes its way to the leaf edge to construct its very first leaf shelter right away. It ventures out of the shelter from time to time to feed on the leaf lamina in the vicinity. As the caterpillar grows, the body assumes a yellowish brown coloration. After reaching about 4.5-5mm in about 4 days, the caterpillar moults to the 2nd instar.

Two views of a 1st instar caterpillar, length: 3.1mm.

Two views of a 1st instar caterpillar, late in this stage, dormant prior to its moult, length: 4.5mm.

The 2nd instar caterpillar resembles the 1st instar caterpillar closely in body features except for the body colour being  pale whitish. The body has a strong yellowish brown undertone   initially but this changes to a duller tone the instar progresses. This instar lasts about 4 days with the body length reaching about 8-8.5mm.

Two views of a 2nd instar caterpillar, early in this stage, length: 6mm.

Two views of a 2nd instar caterpillar, dormant prior to its moult, length: 7.8mm.

The folded leaf shelter of  a 2nd instar caterpillar.

Another folded leaf shelter of a 2nd instar caterpillar, with varying illumination angles to reveal the presence of the caterpillar in the shelter.

The 3rd instar caterpillar differs from the 2nd instar caterpillar in having a body colour which is  strong whitish and with a weak yellowish to greyish brown undertone.  The head capsule is still mostly black  but the area at its lower periphery decolorises to greyish brown.    This instar takes about 5-5.5 days to complete with body length reaching about 13-14mm.

Two views of a 3rd instar caterpillar,length: 9mm.

A late 3rd instar caterpillar, dormant prior to its moult, length: 13.5mm.

The 4th instar brings about a prominent change in the head capsule which is now broader and mostly beige brown in colour. The head is also outlined in dark brown on its periphery and along the frontal cleavage line. The body colour assumes a  solid milky white coloration as the instar progresses.  This instar lasts about 8-10 days with body length reaching about 18-19mm.

Two views of a 4th instar caterpillar, early in this stage, length: 13mm.

Two views of a 4th instar caterpillar,  late in this stage, length: 17mm.

The 5th instar caterpillar has similar body markings and colour as in the late 4th instar except for the colour of its head which has now changed to a uniform beige brown due to the loss of the   frontal dark brown stripe. The 5th instar lasts for about 13-14 days, and the body length reaches up to 28-29mm.

Two views of a 5th instar caterpillar,  early in this stage, length: 20mm.

Two views of a 5th instar caterpillar, late in this stage, length: 27.5mm.

On the last day of 5th instar, the body decolorises  to a very pale translucent white. The caterpillar ceases feeding and stays within its leaf shelter. The pre-pupatory larva prepares for the pupal phase with a series of silk construction work with the main pieces being a silk girdle across the dorsum of its early abdominal segments, and a short and thickened transverse silk band on the substrate at  its posterior end. Both the  girdle and the transverse band are further secured by vertical/oblique threads to the inner wall of the shelter. Soon the pre-pupatory larva becomes dormant in its leaf shelter. Pupation takes place about 1 day later.

Two views of a  pre-pupatory larva of the Dark Flat.

The girdled pupa is secured with its cremaster attached to the short transverse band on the substrate. It has a short thorax, a rather long abdomen and  a pointed rostrum. The body is pale whitish green with no markings. Length of pupae: 18-19mm.

Two views of a pupa of the Dark Flat.

After about 7 days in the pupal stage, the development within the pupa  comes to an end and the pupa turns brown in the abdomen,  dark brown to black in the thorax and wing case. The following day, the adult butterfly emerges from the pupal case.

Two views of a mature pupa of the Dark Flat.

A newly eclosed female Dark Flat.

A newly eclosed male Dark Flat.

References:

• [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
• A Field Guide to the Butterflies of Singapore, Khew S K, Ink on Paper Comm. Pte. Ltd., 2010. 
• Butterflies of Thailand, Pisuth EK-Amnuay, 1st Edition, 2006.

Text by Horace Tan, Photos by Jonathan Soong, Henry Koh, Loke P F, Anthony Wong   and Horace Tan

Random Gallery - Ultra Snow Flat

Random Butterfly Gallery
Ultra Snow Flat (Tagiades ultra)


Nikon D3s ; Tamron 180mm f/3.5 ; ISO 1000 ; 1/160s ; f/10 ; -0.3EV ; Fill Flashed ; Handheld

The Ultra Snow Flat (Tagiades ultra) is a relatively uncommon "flat" of the sub-family Pyrginae.  It has a wingspan of about 38-45mm.  Like most of the other species in the genus Tagiades, the Ultra Snow Flat is often observed sunbathing with its wings opened flat on the top surfaces of leaves.  It is essentially a forest-dependent butterfly and is rarely seen outside the nature reserves.  This pristine individual was photographed feeding on the flowers of the Pagoda Flower (Cleredendron sp).  It was flitting rapidly from flower to flower, feeding with its wings opened flat.  This shot captured some of the backlighting as it was on a tall bush with the forest canopy and the sky in the background.

Favourite Nectaring Plants

Butterflies' Favourite Nectaring Plants 
The Snakeweed (Stachytarpheta indica)

Butterflies need nutrients and sugars, besides other minerals, to survive and go about their daily business.  Very often, I have been asked what types of flowers are attractive to butterflies.  Over years of observations of our winged jewels, there are favourite species of flowering plants that attract butterflies more than others.  For example, if you want to attract butterflies to your garden, roses and orchids are flowering plants that you should not be cultivating!  

This series of blog articles will introduce our readers to the various types of all-time favourite nectaring plants that butterflies prefer.  Hence if you are cultivating a butterfly garden, these are the plants to look out for and include in your horticultural pallete.  

The first plant that will be featured is the common Snakeweed (Stachytarpheta indica).  

Plant Biodata :

Family : Verbenaceae

Genus : Stachytarpheta

Species : indica (syn. jamaicaensis, villosa) and mutabilis

Country of Origin : South America

English Common Name : Snakeweed, Purple Snakeweed, Blue Porter Weed, Pink Snakeweed

The Snakeweed has been described as an erect herb often growing up to 1m tall.  The leaves are opposite and usually bright green.  Each leaf is elliptic oblong and range from 4-11 cm long.  The margins of the leaves are toothed where the teeth are of varying sizes.  The secondary veins on the leaf are inconspicuous beneath.  Leaves can also be variegated on the same plant, but turning all green as they mature. 

Variegated leaf of the Snakeweed

The flowers are found on long, narrow spikes which can range from 15-40 cm long.  The corolla of the flower is bright violet, but there are white and red varieties as well.  The species mutabilis has larger flowers and are usually orange-red.  The corolla tube of the typical indica is pale bluish-violet with 5 short deep purple-blue lobes.  There are two stamens in the corolla tube. Fruits are small, dry and hard. 

Different colours of the Snakeweed flowers

The Snakeweed is typically found in wastegrounds as a weed.  It occurs in the nature reserves of Singapore along cleared paths.  This "weed" is now being cultivated in urban gardens and parks as a butterfly-attracting plant.  

Close up of the most common variety of the Purple Snakeweed flowers

The plant requires moderate watering, and is able to grow in poor soil.  It does well in both full sun and semi-shade. It grows as shrubs and older plants have woody stems.  It has a habit of growing tall and gangly as it matures, and rather sparse.  Leaves are sometimes attacked by insects and mould.  

Many species of butterflies are attracted to the flowers of the Snakeweed.  In particular, the purple variety, which is more common, are visited by almost all the families of butterflies, with the exception of species from the Lycaenidae and Riodinidae families which rarely visit the flowers. 

The common urban Papilionidae like the Common Mormon and Lime Butterfly find the Snakeweed very attractive, and we have observed the butterflies feeding on T. indica as well as the larger but rarer T. mutabilis. 





Of the Pieridae, the Grass Yellows (Eurema spp) are often attracted to the purple flowers of T. indica even in the nature areas, whilst the urban butterflies like the Catopsilia spp. (Emigrants), Psyche (Leptosia nina) and Painted Jezebel (Delias hyparete) often stop to feed at the Snakeweed flowers.  

The Danainae also love the Snakeweed, and we have seen the various Tigers and Crows feeding greedily on the flowers.  Over at Pulau Ubin Butterfly Hill, where the Snakeweed grows in abundance, the Common Tiger, Plain Tiger and the Black Vein Tiger are regular visitors to its flowers.  Members of the Crow (Euploea) family also visit the flowers, often giving a photographer a better chance at taking a good shot of the butterflies when they stop to feed at the Snakeweed.

The larger species of the Nymphalinae, like the Lacewings (Cethosia) - Malay and Leopard, are frequent visitors to the flowers of the Snakeweed.  The Great Eggfly (Hypolimnas bolina) has also been seen to feed on the Snakeweed flowers. The medium-sized species like the Junonia, Phalantha and Doleschallia also visit the Snakeweed flowers from time to time. 

There could also be a correlation between the weight of the butterfly species and the frequency with which these species visit the flowers of this plant.  "Heavier" and large butterflies like the Polyura, Lexias and so on have not been seen feeding on this plant before.  Interestingly, the Satyrinae also avoid the flowers of this plant.  Although, for example, where the Common Palmfly (Elymnias hypermnestra) and the Bush Browns (Mycalesis spp) are found flying in the vicinity of the Snakeweeds, I have only seen on one rare occasion where one of these species fed on the Snakeweed flowers.

Of the Hesperiidae, many of the smaller species love the Snakeweed, often seen zipping from flower to flower to feed.  Even the rarer "flats" (subfamily Pyrginae) visit the flowers. 

It will be interesting to keep a log and checklist of all the species of butterflies found feeding on the Snakeweed.  Obviously, the correlation between physiological attributes of the pollinating requirements of the plant and the types of butterflies and other insects (bees have also been seen at the flowers of the Snakeweed) would be important.  Attributes like size and weight of the butterfly, length and diameter of proboscis, the amount of nectar each flower produces to satisfy the needs of the butterfly and a myriad other considerations would determine why one species of butterfly visits the Snakeweed, and why another does not.  

Future articles in the series will feature other flowering plants that are favourites amongst the feeding butterflies as well as information about the plants themselves.  

Text by Khew SK  : Photos by Chng CK, Khew SK, Koh CH, Loke PF, Tan BJ & Anthony Wong

References :

• Keng, Hsuan : The Concise Flora of Singapore, 1990 ; Singapore University Press
• Foo, Tok Shiew : A Guide to the Wildflowers of Singapore, 1985 ; Singapore Science Centre
• Boo, CM; Omar-Hor, K & Ou-Yang CL : 1001 Garden Plants in Singapore, 2nd Edition, 2006 ; National Parks Board