Friday, October 10, 2014

Butterfly of the Month - October 2014

Butterfly of the Month - October 2014
The Blue Pansy (Junonia orithya wallacei)



This month, we feature a pretty urban sun-loving butterfly to bring some colour and cheer to our readers. The Blue Pansy, particularly the male, seldom fails to attract the attention of any nature lover who sees it in the field. Its bright blue hindwings and eyespots is a good example of Mother Nature's creativity in putting some beauty into our daily lives.




The local subspecies of the Blue Pansy (Junonia orithya wallacei) is named in honour of the renowned British naturalist, explorer, geographer, anthropologist and biologist, Alfred Russell Wallace. His book, The Malay Archipelago, documents his travels and findings in this part of the world. He recorded many of his adventures and discoveries in this book, considered to be one of the best of all journals in scientific exploration in the 19th century.



A road named after A.R. Wallace in Singapore

Wallace's exploits in South East Asia generated widespread interest amongst scientists and ecologists, especially his theories on evolution through natural selection. In particular, Wallace was believed to have collected specimens from our very own Bukit Timah Hill in Singapore. Such was his influence in Singapore that there is even a road named after him! More recently, at the Dairy Farm Nature Park, we can also find the Wallace Trail and the Wallace Education Centre, which was set up to promote environmental education through fieldwork and to encourage nature conservation.




Speaking of the environment, we look forward with greater optimism as the appreciation and the call for the conservation of our environment and biodiversity is gaining traction amongst NGOs and also government organisations. Given the limited land mass of about 714 sqkm in Singapore, it has done relatively well in balancing development and the conservation of its remaining nature areas. There is little to lose and every sqft of our little red dot has to be carefully planned to allow nature and biodiversity to co-exist in harmony with progress and development.




Hobbyist and citizen scientist groups such as ButterflyCircle continue to survey, document, record and research into butterflies in the Singapore environment to help government organisations to better craft policies and direct efforts to conserve our butterfly biodiversity. Species data, caterpillar host plants & early stages, habitat preferences, threatened colonies and ecological behaviour of butterflies are shared via this blog and other reports.



Male Blue Pansy (top) and Female Blue Pansy (bottom)

Coming back to our pretty butterfly of the month, the Blue Pansy is one of four species of Pansies of the genus Junonia found in Singapore. The Blue Pansy is common is parks, gardens and open grassy wasteland. It flies rapidly with a flap-glide flight and is alert and skittish. It is related to the American Common Buckeye (Junonia coenia) and shares some of the physical characteristics with its US cousin.


A female (left) and male (right) Blue Pansy feeding in unison on Bidens flowers

Males of this species are often observed to "dogfight" with each other, and individuals engage in a rapid spiral flight often going up to 10 metres or more. During certain hours of the day, both the males and females may be observed to perch on the tops of leaves with their wings opened flat to sunbathe.




Blue Pansy and their favourite nectaring plants

They prefer to feed on flowers like Lantana, Bidens and other small wildflowers. Occasionally they are seen "puddling" at damp areas on the ground amongst leaf litter and grasses. The species has a wide distribution in Singapore, found in coastal areas, urban parks, nature reserves from Pulau Ubin in the north, mainland Singapore and as far south as Pulau Semakau.




When the weather gets warmer as the day progresses, they are often found perched with their wings folded upright amongst shrubbery and tall grasses. Whilst the upperside of the Blue Pansy is attractive coloured, the underside bears a more subdued and cryptic colouration that allows the butterfly to be reasonably well-camouflaged amongst the undergrowth.


A newly-eclosed male Blue Pansy perching on a dried blade of grass

The male Blue Pansy features black forewings with a pale yellow subapical band and post discal ocelli. The hidwing is a bright blue with a prominent black-rimmed, orange-purple eyespot at the tornal area. The basal area of the hindwing is black.





Females of the Blue Pansy, showing the variability of the colours of the hindwings from totally brown to a restricted patch of blue

Females are more drably coloured usually featuring a brown upperside and occasionally sporting a reduced patch of blue, usually restricted to the submarginal area of the hindwing. The hindwing ocelli of the female are also larger when compared to the male.


A newly eclosed Blue Pansy perching onto its pupal case whilst waiting for its wings to dry

The caterpillars of the Blue Pansy have been successfully bred in Singapore on the Common Asystasia (Asystasia gangetica), a low, ground hugging "weed" that is found commonly in urban gardens and parks, as well as growing as ground cover in disturbed areas at the edges of our nature reserves. This plant is also host to the caterpillars of the Autumn Leaf (Doleschallia bisaltide), Jacintha Eggfly (Hypolimnas bolina jacintha) and Great Eggfly (Hypolimnas bolina bolina)


A mating pair of Blue Pansy perched on the flower of its caterpillar host plant, the Common Asystasia.

Text by Khew SK : Photos by Chng CK, Jerome Chua, Huang CJ, Federick Ho, Khew SK, Koh CH, Loke PF, Nelson Ong, Jonathan Soong, Horace Tan and Benjamin Yam.

Wednesday, October 8, 2014

Butterflies Galore! : Spotted Black Crow

Butterflies Galore!
The Spotted Black Crow (Euploea crameri bremeri)



This Spotted Black Crow was feeding at the flowers of the StringBush at the Butterfly Hill on Pulau Ubin last weekend. It appeared to be very hungry and continued to feed for over half an hour, moving from flower to flower of the bush. A moderately rare species, the Spotted Black Crow's caterpillar has been successfully bred on Gymnanthera oblonga (Sea Rubber Vine) and Parsonsia helicandra from the lactiferous family of plants Apocynaceae.

The Spotted Black Crow flies slowly when undisturbed, and is sometimes observed puddling at sandy stream banks in the nature reserves. A closely-related species, the Blue Spotted Crow (Euploea midamus singapura) is very similar in appearance but has more squarish subapical spots on the forewing and lacks a small spot at the costal area of the forewing.

Saturday, October 4, 2014

Life History of the Common Redeye

Life History of the Common Redeye (Matapa aria)


Butterfly Biodata:
Genus: Matapa Moore, 1881
Species: aria Moore, 1866
Wingspan of Adult Butterfly: 35-40mm
Caterpillar Local Host Plants: Bambusa_heterostachya (Poaceae; common name: Malay Dwarf Bamboo), Bambusa multiplex (Poaceae, common name: Hedge Bamboo, Chinese Dwarf Bamboo), other Bambusa spp., Dendrocalamus spp.



A male Common Redeye showing the brand on the forewing.

The close-up view of the red eye of a Common Redeye.

Physical Description of Adult Butterfly:
On the upperside, the wings are dark buff brown to black with the hindwing cilia pale yellowish grey. The male has a oblique, greyish brown, brand in spaces 1b and 2 on the forewing. On the underside, the wings are ochreous brown. The eyes are red.



Field Observations of Butterfly Behaviour:
The Common Redeye is moderately rare in Singapore although its caterpillars can be found rather easily on its host plants (various bamboo spp.) on many occasions. The adults are mainly sighted at locations where there are bamboo clumps in the vicinity, and such locations could be urban parks, gardens, wastelands or the nature reserves. The adults are fast flyers and rests with its wings folded upright.





Early Stages:
The Common Redeye is known to utilize a number of bamboo spp. as its larval food plants. The caterpillars feed on bamboo leaves in all instars, and live in rolled-up leaf shelters.

Local host plant #1: Bambusa multiplex.

Local host plant #2: Bambusa vulgaris.

The eggs are laid singly on the underside of a leaf of the host plant. At times, multiple oviposition visits could lead to several eggs deposited on the same leaf. Typically the egg is concealed in a mass of setae from the abdominal tip of the mother. It is dome-shaped with its micropylar sits atop in a large orangy/reddish spot. There are many longitudinal ridges running radially from the micropylar. The colour of the egg is initially pale yellowish beige but becoming purplish as the egg matures. It is rather large with a diameter of about 1.6mm.

Two views of an egg of the Common Redeye, diameter: 1.6mm.

A sequence of three shots showing the development of the maturing egg on the left, while the one on the right is still in its early stage of development.

It takes about 5 days for the egg to hatch. The young caterpillar eats just enough of the shell to emerge, and then immediately proceeds to finish the remaining egg shell. The newly hatched has a length of about 3.2mm. Its bright crimson red body is cylindrical in shape with a small number of very short and tiny dorso-lateral and lateral setae. There is a tuff of moderately long setae on the posterior segment. Its head is black with a black collar lying behind it on the prothorax.

Two views of a newly hatched 1st instar caterpillar, length: 3.5mm.

After consuming the egg shell, the newly hatched caterpillar  constructs its first leaf shelter, typically at the tip of a leaflet of the palm frond. The body colour loses its intense reddish tone after a few feeding sessions on the leaf. The 1st instar takes about 2 days to complete with body length reaching about 6.5-7mm.

Two views of a 1st instar caterpillar, length: 5mm.

A 1st instar caterpillar venturing out of its leaf shelter to feed on the leaf lamina in the vicinity.

The body of the 2nd instar caterpillar resembles that of the first instar. Initially the body is yellowish red with red tones gradually loses its prominence sa the instar progresses. This instar lasts a total of 2-3 days with the body length reaching up to 8.5-9mm.

Two views of a 2nd instar caterpillar, newly moulted, length: 5.2mm.

Two views of a 2nd instar caterpillar,  length: 8mm.

The 3nd instar caterpillar resembles the 2nd instar caterpillar except for a more yellowish green body colour, and the presence of a small brownish patch on the anal plate. By the end of this instar, the body colour is entirely yellowish green. This instar lasts a total of 3-4 days with the body length reaching up to 12-13mm.

Two views of a 3rd instar caterpillar, early in this stage, length: 9mm.

Two views of a late 3rd instar caterpillar, dormant prior to its moult, length: 12mm.

The 4th instar caterpillar differs from the 3rd instar caterpillar in having the colour of the head capsule changed to dark brown or orange. This instar lasts 6-8 days with the body length reaching up to 18-20mm.

Two views of a 4th instar caterpillar, early in this stage,  length: 12.88mm.

Two views of a 4th instar caterpillar, late this stage, length: 18mm.

Two views of another 4th instar caterpillar, with orange-coloured head, late this stage, length: 17mm.

A late 4th instar caterpillar, with dark brown head, dormant prior to its moult, length: 19mm.

The 5th instar caterpillar has a head which is orange-coloured with no markings, and its body much more whitish in appearance with a slight hint of a yellow tone. The anal plate does not bear any marking.

A newly moulted 5th instar caterpillar (moulted from the one shown in the pic above).

Two views of a 5th instar caterpillar, late in this stage, length: 24mm.

The leaf shelter of a 5th instar caterpillar sighted in the field.

The 5th instar takes about 7-9 days to complete with the body length reaching up to 24-29mm, Towards the end of this instar, the caterpillar ceases feeding and its body shrinks. Next it proceeds to construct the pupation shelter which is cylindrical in shape, open at the distal end but sealed at the other. In the pupation shelter, the caterpillar secretes large quantity of a whitish waxy substance, and spins a silk pad to anchor itself at the posterior end. Soon the caterpillar becomes dormant in the pupation shelter. This prepupatory phase lasts for 1-1.5 days.

The pupation shelter of a Common Redeye caterpillar.

A pupation shelter opened to reveal a pre-pupa of the Common Redeye.

Pupation takes place within the shelter. The pupa uniformly whitish with a yellowish undertone. It is secured via cremastral attachment to a silk pad. It has a short thorax and a rather long abdomen. Length of pupae: 20-22mm.

Two views of a pupa of the Common Redeye, length:24mm

After 6 days, the pupa becomes mostly black and the red eyes are visible through the pupal skin. Eclosion takes place the next day.

Two views of a mature pupa of the Common Redeye.

A newly eclosed Common Redeye.

References:
  • [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, Malayan Nature Society, 1992.
  • Butterflies of Thailand, Pisuth Ek-Amnuay, 2nd Edition, 2012.
  • A Field Guide to the Butterflies of Singapore, Khew S.K., Ink On Paper Communications, 2010.
Text by Horace Tan, Photos by Benedict Tay, Bobby Mun, Sunny Chir and Horace Tan