Friday, September 30, 2016

Butterfly of the Month - October 2016

Butterfly of the Month - October 2016
The Plain Tiger (Danaus chrysippus chrysippus)



It's the eighth month of 2016 already! Celebrated across the world wherever there are Chinese communities, the Mid-Autumn Festival (Zhong Qiu Jie) falls on the 15th day of the eighth lunar month of the Chinese calendar (although this actually fell in Sep according to the Gregorian calendar). This coincides with the autumn equinox when the moon is at its roundest and brightest. It is a time for family and friends to gather with their colourful lanterns and to admire this beautiful sight and give thanks for harmony, happiness and the fullness of life.





It was also a time where offerings of mooncakes and pomelos are made to the moon. In modern times, however, mooncakes come in more creative (but fattening!) forms from durian and chocolate fillings to multi-coloured snowskin and quadruple preserved eggyolk varieties. There were even recent comparisons of how many calories one would consume in a mooncake, compared to Singapore's local gastronomic delights (of the 'sinful' types like char koay teow, chicken rice and roti prata). No matter, this once-in-a-year indulgence is probably worth it!



The previous month also saw an unprecedented weather phenomenon in the most powerful typhoon recorded in 2016, called Meranti. With estimated wind speeds of up to 285 km/h, the super-typhoon struck the Philippines, Taiwan and China, causing widespread damage and fatalities. Hot on the heels of Meranti, another typhoon, Megi, albeit less powerful, made landfall in Taiwan, smashing into the island and causing at least four deaths and numerous injuries.




In Singapore, we saw the ninth edition of the Formula 1 Singapore Grand Prix. Reputed to be the only night F1 race in the world, the 2016 Singapore GP saw German Nico Rosberg on the winner's podium. One wonders if the interest in F1 waning in Singapore, as it was reported that ticket sales for 2016 was possibly the lowest ever, since the F1 came to Singapore in 2007. Nature buffs were treated to a sight where a Water Monitor ran across the F1 track and caused some ruckus amongst the race officials.



Back to nature, and we feature October's Butterfly of the Month 2016, the Plain Tiger (Danaus chrysippus chrysippus).  This common but pretty butterfly has become a dominant species in our urban butterfly gardens where its caterpillar host plants, the Blood Flower (Asclepias currasavica) and the Crown Flower (Calotropis gigantea) are cultivated. At times, it can almost be considered abundant, as many Plain Tigers flutter freely amongst the nectaring plants.




Back in the mid-90's when I was participating in butterfly biodiversity surveys with the National Parks Board, the Plain Tiger was not as common as it is today. One might even consider the species a relatively rare species, as few individuals were sighted. Today, with the widespread cultivation of its caterpillar host plants in urban gardens, the Plain Tiger is now a regular feature species in many of these butterfly gardens.




The Plain Tiger has rich fulvous orange forewings with a broad black apical border bearing a series of white spots. Two forms occur in Singapore - form-chrysippus, where hindwings are unicolourous with the orange forewings; and form-alcippoides, which has white hindwings. The white-hindwinged form is by far the commoner of the two forms in Singapore.






Whilst it is considered common, the Plain Tiger tends to be quite local in that it is always found not far from where its caterpillar host plants are cultivated. It is seldom seen in the forested nature reserves and is more of an urban butterfly species.




Like many other species of the Danainae sub-family, the Plain Tiger displays aposematic colouration which advertises its impalatability to would-be predators. It serves as a model to the female of the Danaid Eggfly (Hypolimnas missippus missippus). The latter species has been found in Singapore, but extremely rare. However, thus far, there is no sighting of the female of the Danaid Eggfly in Singapore.



The Plain Tiger flies with a slow and unhurried flight, fluttering from flower to flower and frolicking amongst other individuals of the same species. It is partial to the semi-dried plant of the Indian Heliotrope (Heliotropium indicum). The male Plain Tiger is also attracted to the Rattlebox Pea (Crotalaria retusa), where it claws the pea pod and then feeds on the fluids that the damaged pea pod exudes.





The male Plain Tiger can be distinguished from the female by an extra 'sex brand' on the hindwing. The white spot which is surrounded by black ring, is quite distinct and obvious and easily tells apart the males from the females. This spot, which bulges slightly, consists of a cluster of specialised scent scales used to attract females.




The colourful caterpillar feeds quite openly and can defoliate the host plant quite quickly. As the caterpillars sequester the poisonous sap from the host plant, they are distasteful to predators and birds tend to leave them alone.

Text by Khew SK : Photos by Bob Cheong, Sunny Chir, Chng CK, Brian Goh, Khew SK, Loke PF, Bobby Mun, Anthony Wong, Mark Wong and Benjamin Yam

Friday, September 23, 2016

Eye In the Sky

Eye In the Sky
Butterfly Gardens : A View from the Top


An aerial view of the Butterfly Garden at Fusionopolis North

Singapore's urban butterfly gardens have been featured on this blog regularly. Our winged jewels thrive in these specially-planted gardens that attract them to visit the flowering plants to feed and their host plants to lay their eggs. With judicious planting of appropriate butterfly nectaring and host plants, these butterfly gardens can attract many species of butterflies.



I have always wondered what these urban gardens would look like from the viewpoint of a butterfly, soaring high in the sky and scanning the landscape below for their favourite flowers. Imagine a Common Birdwing (Troides helena cerberus), flying majestically 20-30 metres or even higher, above the lush greenery, and looking down and searching for its host plants or some of its favourite nectaring plants when it is hungry.



Human eye view of the Butterfly Garden at Fusionopolis North

Thus far, we have been featuring photographs of our butterfly gardens from a human's perspective - walking on the ground and looking around at the butterflies fluttering from flower to flower. Our photos of the butterflies feeding, sunbathing or frolicking around is limited to what we can encounter at our eye-level. Our views of the greenery that surrounds us, is what we can see, with our feet planted firmly on the ground.



Recently, a colleague loaned me his quad-copter drone and I thought that it would be a good opportunity for me to visit some of the butterfly gardens that I had featured before, and how they would look like from the air. These days, there are so many types of flying drones available online and in technology shops locally and abroad. As can be expected, quite a large percentage of these drones are made in China - even the "high end" DJI Phantoms that are very popular amongst drone enthusiasts.


The Blade Chroma quadcopter drone with CGO3 4K camera

So I got my hands on a Yuneec Blade Chroma that comes with a CGO3 4K camera that can shoot 30fps videos or 12 Mp stills. The integrated 3-axis gimbal holds the camera still and video footages appear very stable. After logging a few hours' flight time as a novice drone pilot, I set out to some of our local butterfly gardens to take a look at how they look like "from up there".

Butterfly Sanctuary @ the Meadows, Gardens by the Bay


Butterfly Sanctuary @ the Meadows, Gardens by the Bay

The first butterfly garden was the Butterfly Sanctuary at the Meadows, Gardens by the Bay. Taking the drone up to a cruising height of about 50m, the landscaping at the Butterfly Sanctuary appeared rather thin and arranged along a linear path. The nectaring plants flanked the path, visible from the air, where most of the butterfly activity can be expected. The surrounding greenery and taller trees provided shade and expanded the area where the butterflies flew around.

Hort Park Butterfly Garden



The next butterfly garden that I visited was the one at Hort Park. Originally in an enclosure, the butterfly garden is now an open garden with free-flying butterflies like most of our environmentally-friendly butterfly gardens. The layout of the butterfly garden, complete with host and nectaring plants, is designed on the standard plot sizes at Hort Park, and strung in a linear fashion. Over the years, the tall trees along the trail have grown to a significant height, and provides shade for parts of the butterfly garden.


Butterfly Garden @ Hort Park

From the top, the clusters of host and nectaring plants like the Snakeweeds, Lantanas, Stringbush, Golden Dewdrops and Dutchman's Pipevine appear like a mass of green and the colours of the flowers were indistinguishable from 30-40m up.

Fusionopolis Butterfly Garden



Moving to the next urban garden nearby, I visited the Fusionopolis North Butterfly Garden. This recently-completed butterfly garden was still rather open and unshaded as the larger trees have yet to mature and extend their green canopies. From the air, the network of concrete footpaths was quite distinct as were some of the hardscape features.


Butterfly Garden at Fusionopolis North

Up at 35m above, this butterfly garden appears more squarish in plan, with all the butterfly-attracting plants visible in a patchwork of greenery with the sinuous footpaths winding through the garden. The large trees flanking the butterfly garden provided a boundary and much-needed shade from the hot environment where the newly-landscaped gardens were planted.

Jurong Eco-Gardens Butterfly Garden


Butterfly Garden at Jurong Eco Garden

The last butterfly garden that I visited with the Blade Chroma, was the one at Jurong Eco-Gardens. Located in a more sub-urban environment with slightly more undeveloped greenery (for the moment), the butterfly garden is also laid out along a linear trail, with the butterfly-attracting plants flanking the trail.


A closer butterfly-eye's view of the Butterfly Garden at Jurong Eco Garden

From the air at about 40m up, the large red clumps of the Pagoda Flower (Cleredendron paniculatum) were visible. The wide boardwalk can be clearly seen, and the surrounding waterbody and larger adjacent trees formed a lush boundary to the butterfly garden.

Take a flight around the butterfly garden at Fusionopolis North! (You may have to run the video a couple of times to get a better resolution)

And so you now know how these butterfly gardens look like from a high-flying butterfly's viewpoint. At this point in time, it is unlikely that a drone can successfully take close-up butterfly shots at the treetop canopies. But at the rate technology is advancing these days, someone may just invent a zoom lens that can do just that in the future!


Three Common Tree Nymphs (Idea stolli logani) soaring high in the air

Text and Photos by Khew SK & Loke PF

Special thanks to my colleague and good friend, Vincent, who loaned me his Blade Chroma quadcopter (and is in the process of 'poisoning' me to get the awesome DJI Phantom 4 drone)

For those who are curious, there are currently no permits required to purchase a drone in Singapore. However, there are regulations and limits on flying a drone and you should familiarise yourself with the prevailing regulations under the Civil Aviation Authority of Singapore (CAAS).

Saturday, September 17, 2016

Life History of the Felder's Royal v2.0

Life History of the Felder's Royal (Tajuria mantra mantra)


Butterfly Biodata:
Genus: Tajuria Moore, 1881
Species: mantra C. & R. Felder, 1860
Subspecies: mantra C. & R. Felder, 1860
Wingspan of Adult Butterfly: 31-35mm
Caterpillar Local Host Plant: Macrosolen cochinchinensis (Loranthaceae common names: Common Chinese Mistletoe, 鞘花). .




Physical Description of Adult Butterfly:
On the upperside, the male is shining greenish-blue and the female is paler purplish blue. Both sexes have a broad apical black border in the forewing, and a black costal border in the hindwing with inner edges evenly curved to below vein 6 in male and to vein 4 in female. The female has additional marginal spots at tornus and in spaces 1b, 2 to 4. On the underside, both sexes are drab greyish-brown. The forewing post-discal line is much closer to termen than to the cell-end. The hindwing has large black tornal spots in spaces 1a and 2 which are broadly orange-crowned. There are two pairs of white-tipped tails at ends of veins 1b and 2 respectively.




Field Observations:
This species was recently re-discovered in Singapore in 1999. It is relatively rare locally. Sightings of this species have been more frequent in the Southern Ridges than in the Central Catchment Reserve Area. Around noon, the fast-flying adults have been sighted taking nectar at flowering plants in both hill parks and in gardens sited along the fringe of nature reserves. At times several adults could be seen dog-fighting at tree-top level in the mid afternoon.



Early Stages:
Only one local host plant has been recorded for the Felder's Royal. The plant, Macrosolen cochinchinensis is a parasitic plant growing on branches of other plants. Caterpillars of the Felder's Royal feed on the young and developing leaves of this host, with the 1st instar initially skimming the leaf surface and the later instars eating the leaf along the edges.

Local host plant: Macrosolen cochinchinensis.

Eggs are laid singly on the underside of leaves, young shoots, on or in the vicinity of flower buds of the host plant. Each egg is about 0.8mm in diameter, white with a strong greenish tinge when freshly laid. It is burger-shaped with a depressed micropylar at the pole and a surface reticulated with rather large polygonal depressions.

Two views of an egg of the Felder's Royal, laid among leaf buds of the host.

An egg of the Felder's Royal laid on the leaf bud of host.

It takes 3-4 days for the egg to hatch. The young caterpillar consumes just enough of the egg shell to emerge. With a length of about 1.2mm, it is with pale brownish lateral bands. Long setae (hairs) run along the length of the body dorsally as well as sub-spiracularly. The caterpillar assumes the typical woodlouse body shape as it grows in this instar which lasts about 3 days and sees the body length increased to about 3.3mm. On the last day of this instar, raised dorsal tubercles become prominent and reddish brown patches appear laterally.

Two views of a 1st caterpillar, newly hatched, length: 1.2mm.

Two views of a 1st instar caterpillar, length: 2.75mm.

Two views of a late 1st instar caterpillar, length:3.3mm.

The 2nd instar caterpillar has a diamond-shaped prothoracic shield dark in color. Dorsally, it bears prominently projections, one to each of abdominal segments 1 to 6, and two to each of thoracic segments 2 and 3. Reddish brown and pale patches decorate sides of the body. The posterior segments from the 7th abdominal segments onwards are fused together to take on a shield-like appearance with a dark patch sitting on top of it. The 2nd instar lasts for 3 days and reaches a length of about 5.5-6mm. Even in this early stage, the dorsal nectary organ and tentacular organ are very prominently featured on the shield-like posterior. The dorsal projections on segments 2, 3 and 6 turn greenish towards the end of this instar.

Two views of a 2nd instar caterpillar, newly moulted, eating its exuvia, length: 3.8mm.

Two views of a 2nd instar caterpillar, length: 4.2mm.

Two views of a 2nd instar caterpillar, late in this stage, length: 5.3mm.

The 3rd instar caterpillar looks similar to the late 2nd instar caterpillar but with greater contrast between pale beige coloration with dark brown to black coloration on the body. As the body grows in size to a length of about 10-11.5mm, the color of shading on both the anterior and posterior parts also darkens. After 3 days in this stage, it moults again.

Two views of a 3rd instar caterpillar, length: 8.9mm.

Two views of a 3rd instar caterpillar, length: 11.5mm.

The 4th (and final) instar caterpillar initially resembles the late 3rd instar caterpillar. Over the next 2 days, the color of the body gradually darkens. Mid body segments (excluding the dorsal ridge) become dark brown in color. Both the anterior and posterior segments are dominated by brown shadings. The carapace-shield also features a wrinkled surface. In addition, the dorsal projections on abdominal segments 2, 3 and 6 lose their green coloration and take on the same pale yellowish brown of the other dorsal projections.

Two views of an early 4th instar caterpillar, newly moulted and eating exuvia, length: 10.5mm.

Two views of a 4th instar caterpillar, length: 17mm.

The 4th instar lasts for 4 days and the body reaches a length of about 19-21mm. In the last day of this stage, more dramatic color changes take place. The shield-like posterior segments take on a bright orangy brown coloration where the mid body segments assume a contrasting dark green coloration. The anterior body segments turn lighter brown in coloration. Nearing the end of this instar, the caterpillar ceases feeding, and its body shrinks in length. Soon it comes to rest at a spot on the leaf surface and prepares for its pupation.

A 4th instar caterpillar of the Felder's Royal feeding on an Ixora flower.

The pre-pupatory caterpillar prepares for pupation by spinning a silk pad to which it attaches itself via anal claspters. Even during this pre-pupal stage, color changes continue to take place (see the next two pictures).

Two views of an early pre-pupa of the Felder's Royal.

Two views of a late pre-pupa of the Felder's Royal.

Pupation takes place after about 1 day of the pre-pupa phase. The pupa is held firmly via its cremaster to the silk pad on the leaf surface. It is 12-13mm in length, mostly green with yellowish green patches. There are two sets of brown to reddish brown dorsal markings. The pupa was observed to react to an external disturbance by jerking up and down.

Two views of a pupa of the Felder's Royal.

Seven days later, the pupa becomes darkened, mostly in the thorax and wing pads. The bluish patch on the forewing upperside can now be seen in the wing pads. The next day the adult butterfly emerges from the mature pupa.

Two views of a mature pupa of a Felder's Royal.

A newly eclosed Felder's Royal.

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, 2nd Edition, 2015.
Text by Horace Tan, Photos by Jonanthan Soong, Nelson Ong, Anthony Wong and Horace Tan