17 February 2019

Assorted Nectaring Plants - Part 2

Butterflies' Nectaring Plants
Assorted Flowering Plants - Part 2


A female Blue Pansy feeding on the flower of the Feather Cockscomb

In our earlier article on assorted flowering plants that attract butterflies to feed on them, we featured six plants that some butterflies visit for their nectar source. Again, it is important to point out that some of these plants, whilst featuring flowers that may appear pretty and attractive to us human beings, may not necessarily be all-time favourites with butterflies.


A female Plain Tiger feeding on the flower of Yellow Cosmos 

In Part 2 of Butterflies' Assorted Flowering plants, we feature another six species of plants whose flowers some butterflies occasionally visit to feed on. Many of these plants are cultivated for their ornamental and colourful flowers in landscaped parks and gardens.

7. Honolulu Creeper (Antigonon leptopus)


A Leopard Lacewing at the pretty pink flowers of the Honolulu Creeper

This Mexican native is a herbaceous slender climber that features pretty pink flowers. There are tendrils that arise from the ends of the inflorescence that aid in climbing up trellises and pergolas. It is often found in commercial butterfly enclosures in the region. Tea made from leaves of this plant is used to treat high blood pressure, diabetes, flu and menstrual pains.



The plant can be found in Singapore at the Botanic Gardens, and grows wild at the Dairy Farm Nature Park near the Wallace Education Centre. We have found small Lycaenids like the Cycad Blue and Gram Blue feeding on the pink flowers in the wild. Larger butterflies like the Leopard Lacewing and some Danainae are occasionally seen feeding on the flowers where other more popular nectaring sources are scarce.

8. Feather Cockscomb (Celosia argentea)



Healthy shrubs of the Feather Cockscomb at an urban park in Singapore

The Feather Cockscomb is an attractive shrub that is often found as feature plants in landscaped gardens and used as coloured highlights in the landscaping palette of plants. Originating from tropical Africa, this plant is an annual and needs to be cut down and replaced as the plant grows old. The feathery flowers is used in floral arrangements or ikebana either live or dried.



Found in some open butterfly gardens the Feather Cockscomb has been observed to attract only a handful of butterfly species of the Danainae like the Blue and Dark Glassy Tigers, Blue and Peacock Pansys and a small variety of Lycaenidae.

9. Blue Butterfly Bush (Rotheca myricoides)


A Slate Flash feeding on the flower of the Blue Butterfly Bush

Called a "Butterfly Bush", the Blue Butterfly Bush is unfortunately, not particularly attractive to butterflies. The curious name of the plant is due to its resemblance to a butterfly. It is a perennial woody bush that grows up to 2-3 m tall. The attractive flowers feature unique long, white to bluish stamens that arch over the petals which serve as a landing platform for insect pollinators.



Hungry butterflies feeding on the flower of the Blue Butterfly Bush

Usually cultivated in parks and gardens, the flowers attract the smaller species of the Lycaenidae and Hesperiidae butterflies. The occasional larger Leopard Lacewing has been observed to visit the flower when other nectaring sources are in short supply. The smaller species like the Common Grass Yellow, Cycad Blue, Slate Flash and a small variety of skippers have been seen on the flowers of the Blue Butterfly Bush.

10. Indian Heliotrope (Heliotropium indicum)



The Indian Heliotrope is a "magnet" for the Tigers and Crows

This annual herb that probably originates from South America and Tropical Asia is a well-known "Danainae magnet". The low-growing shrub, when pulled out by the roots and hung upside down to dry, attracts many species of Tigers and Crows very quickly. The small flowers (3-4 mm wide) are light purple or white with a yellow centre.



The fresh flowers are mainly visited by butterflies of the subfamily Danainae like the Plain Tiger, Striped Blue Crow and Glassy Tigers. Curiously, we have not observed any other species of butterflies feeding on the flowers.

11. Yellow Cosmos (Cosmos sulphureus)/Wild Cosmos (Cosmos caudatus)



Top : Yellow Cosmos and Bottom : Wild Cosmos flowers in pretty shades of yellow and pink

This ornamental plant with cheery bright yellow, orange and pink flowers are a favourite with gardeners wanting to add colour to their patch of greenery. The leaves of the plant can be eaten raw and used in Malay cuisine (hence the plant is called Raja Ulam). It forms a type of salad in Malay cuisine in combination with other vegetables and garnishing, and eaten with rice. The plant originates from tropical South America. There are many species of Cosmos with colourful flowers that can be found here.




Urban butterflies in parks and gardens often visit the colourful flowers of the Cosmos spp. to feed on the nectar. Amongst these, the Nymphalinae and Danainae are the most regularly seen on these colourful flowers, besides the occasional Pieridae and Hesperiidae species. Where it is cultivated in a free-ranging butterfly garden, the Plain Tiger and Glassy Tigers are often seen feeding on the flowers of the Cosmos.

12. Water Jasmine (Wrightia religiosa)


A Dark Glassy Tiger feeding on the fragrant white flower of the Water Jasmine

This woody shrub is a native to Southeast Asia, and is often associated with religious use. The plant is considered sacred, and can often be found in the vicinity of Buddhist temples in Thailand. The Water Jasmine, called "shui mei" (水梅) or literally "water plum", is cultivated in private gardens for its delicate white flowers and intense fragrance. The Water Jasmine is also a favourite with bonsai enthusiasts as the plant can be pruned and can form interesting shapes when managed well.


A Five Bar Swordtail taking nectar from the flower of the Water Jasmine

The fragrant white flowers sometimes attract the larger butterflies and some skippers, but not many species favour it. Even when the flowers are in full bloom and the fragrance is intense and strong to us human beings, it is curious that it is somehow not as attractive to butterflies. Some of the Glassy Tigers and Swallowtails have been observed searching for nectar from these flowers.

Text by Khew SK : Photos by Bob Cheong, Khew SK, Bene Tay and Anthony Wong

Assorted Nectaring Plants - Part 1

References : 

09 February 2019

Butterfly of the Month - February 2019

Butterfly of the Month - February 2019
The Common Imperial (Cheritra freja frigga)



Chinese communities all over the world welcomed the Year of the Pig on 5 Feb 2019. The pig is the the twelfth animal in the 12-year cycle of Chinese zodiac sign and 2019 completes the cycle that started in 2006. This year's pig is the "Earth" pig according to the Chinese almanacs.




According to the Chinese astrology , 2019 is a great year to make money, and a good year to invest! 2019 is going to be full of joy, a year of friendship and love for all the zodiac signs; an auspicious year because the Pig attracts success in all the spheres of life. Sounds generally good enough for me! :)



It is always a nice feeling to shed the old and bring in the new, especially when 2018 wasn't a particularly good year on many fronts. It was heartbreaking when my mom left us at the age of 87 in early January. That month was just a total blur of sadness, grief and pain - combined with a flurry of activities.



But thankfully, our family support and well-wishes of friends helped us tide over that period. Mom would have wanted us to carry on and be happy that she no longer had to endure the suffering that she had to go through in the last 4 months of her life. To all the relatives and friends who were there for us, I thank you from the bottom of my heart. My apologies if I could not thank each of you individually, but you know who you are, and you have my humble gratitude that you reached out in my family's moments of darkness.



So life goes on for those of us, as we ponder our own mortality, and what we plan to leave behind us in the time that we have left in this world. Whatever little good that we can contribute to the world around us, we should. And we move on to do our little bit to make the world a better place in our own ways.



And we continue to bring cheer during this Chinese New Year period and look forward to better times that we have to work hard for. Our world is changing rapidly in many tangible and intangible ways. Disruptions of all sorts and sizes abound, and we have to face new challenges all the time. But that's what makes life 'colourful' and less mundane, even though we struggle to maintain order and stability around us.



Let us come back to our colourful friends, the butterflies. This month, we feature the Common Imperial (Cheritra freja frigga), a delicate long-tailed beauty of the Lycaenidae family. It is always a breath-taking experience to see this butterfly flutter amongst the shrubbery with its elegant white tails trailing behind.


Upperside of a male Common Imperial

The Common Imperial is more often seen in urban parks and gardens than within the forested nature reserves in Singapore. This may be because the species' caterpillars depend on a variety of host plants that are more commonly found in urban areas. The caterpillars of the Common Imperial have been successfully bred on Callerya atropurpurea, Duabanga grandiflora, Adenanthera pavonina (Red Saga) and Cinnamomum iners (Wild Cinnamon). The last two host plants are common roadside trees.




The upper wing surfaces of the butterfly is a deep purple-blue in the male, and dark brown in the female. The tornal area on the upperside features large black quadrate spots. The underside is mainly white on the hindwing with the forewing a shade of orange. The tornal spots on the hindwing is overlaid with iridescent greenish-blue scaling. The Common Imperial has white tails along veins 1a, 2 and 3 of which the one at vein 2 is the longest.




The Common Imperial has a rapid flight and is often skittish, preferring to stay high in the treetops. Where it is found amongst low shrubbery, males have a tendency to perch on a few favourite spots and 'attacks' any intruders into its space. Females descend to the lower levels to oviposit in the mid- to late afternoon hours of the day.


A Common Imperial sometimes displays a behaviour where it hides under a leaf

A Common Imperial puddling at a sandy streambank

At certain hours on hot humid days, males may be seen opening their wings flat to sunbathe. At other times, it displays a behaviour where it hides under a leaf with its wings folded upright. It is not often seen puddling at damp streambanks or muddy trails, but there have been occasions where males are observed puddling.


A mating pair of the Common Imperial

Sightings of this species have been more regular and often in the past decade. However, it appears to have become rarer in the recent few years, having been spotted mainly in the parks of Singapore's Southern Ridges. As with many of the English names of butterflies, those that carry the "common" prefix are often not as common as one is led to believe. The Common Imperial is a species that is considered moderately rare to rare, and is usually observed singly.

Text by Khew SK : Photos by Goh LC, Federick Ho, Khew SK, Jonathan Soong, Horace Tan, Tan Sze Siong and Anthony Wong

03 February 2019

The Malayan Jester - Permanent Resident?

The Malayan Jester - Permanent Resident?
A Species here to stay? 


A Malayan Jester perches on top of a leaf with its wings opened flat to sunbathe

Last weekend, we discussed the establishment of a colony of a species that had long disappeared from Singapore - the Angled Castor. Very rare in Singapore for many years, the species made a surprising comeback and became locally common again on Pulau Ubin where its caterpillar host plant, the Castor Oil Plant, grows in abundance.


A puddling Malayan Jester shows its marbled undersides with its cryptic patterns

Over the past few months, another species, the Malayan Jester (Symbrenthia hippoclus selangorana) was repeatedly observed in the Dairy Farm Nature Park area, at the foothills of Bukit Timah Nature Reserve. The Malayan Jester was first recorded as a new discovery for Singapore back in Feb 2012 when a few individuals were spotted at the Nanyang Technological University area. However, no other sightings were made after that year.



Recently, more sightings of the Malayan Jester were recorded, at the northern part of Singapore in Admiralty Park, and many sightings of both males and females at the Dairy Farm area. Again, the appearance of pristine individuals implied that these were not stray vagrants that came from Malaysia. It is therefore highly likely that a breeding population has now been established in Singapore.



From the recent flurry of postings of the Malayan Jester on social media, this is strong evidence of a relatively healthy but small population of the species around the Dairy Farm area. Again, has something changed in the ecology of the area, or has some species of plant that the caterpillars of the Malayan Jester feeds on, become more abundant? Between 2012, when it was first discovered, and 2018, was the species slowly establishing itself somewhere within the forests of Singapore?



We probably have more questions than answers. But let us take a closer look at the Malayan Jester. There are several species of the genus Symbrenthia in West Malaysia. The early authors did not record any of the species in Singapore. It was added to the Singapore checklist only in 2012. The cryptic species has many lookalikes and with more recent photos available, and the keen eye of Dr TL Seow, he opined that the Singapore population is S. hippoclus (Malayan Jester) and not the closely related S. lilaea (Common Jester).


© Life Histories of Asian Butterflies Vol I by Igarashi and Fukuda

The life history of the Malayan Jester has been recorded from Malaysia by Igarashi and Fukuda . The host plants that they bred the caterpillars of this species on, are Boehmeria glomerulifera, Oreocnide trinervis and Oreocnide pedunculata all from the Urticaceae family. It is likely that one or all of these plants are also found in Singapore and in that location if there is a breeding population of this species.


Left : Records of the life history of the Malayan Jester in Malaysia show that the female lays between 20-50 eggs at one sitting. 
Right : One of the host plants recorded for the Malayan Jester in Malaysia - Oreocnide pedunculata

The species has been described as "common in low mountains from 700-1400m". In Malaysia, the species has been observed to lay "egg masses consisting of 20-50 ova, each laid on the undersurface of leaves. The newly hatched larvae aggregate and feed on the hostplant leaves leaving the veins uneaten in web patterns." Given that the female can lay that many eggs, the species can possibly become more common in the years to come, if there is a sustainable supply of its caterpillar host plants, and that the species is not vulnerable to predators or in-breeding problems.



The Malayan Jester is black with orange bands arranged horizontally across both wings. There is a short pointed tail on the hindwing. The underside is pale orange-brown and highly variegated. The underside hindwing is a pale purple with the post-discal area more heavily dark-dusted and more prominently marked than in the Common Jester.



In the Common Jester, the discal spot in space 3 on the underside of the forewing is unicolourous orange in the male and very nearly so in the female, whilst in the Malayan Jester, this spot is outwardly pale pinkish in the male and nearly all pinkish in the female.




The two species are difficult to separate with the physical characteristics alone, but we will go with Dr Seow's view that this is Symbrenthia hippoclus selangorana (Malayan Jester) until more evidence is available to prove that his conclusion otherwise. In Butterflies of the Malay Peninsula 4th Edition, it was also mentioned that Symbrenthia lilaea luciana (Common Jester) is "most often found in the hills above 3,000 feet." - making the Singapore species more likely to be the Malayan Jester, which is a lowland species.




The Malayan Jester is skittish and flies rapidly. Males are usually encountered puddling at damp muddy footpaths in forested areas, whilst females are more likely observed foraging amongst low shrubbery. In the early morning hours, both sexes can sometimes be observed sunbathing on the tops of leaves with their wings opened flat.



Whether or not the Malayan Jester will continue to stay in Singapore will depend on a number of variable factors. For the moment, should the status of another "very rare" seasonal migrant be amended to "moderately common" at this locality at the foot of Bukit Timah Hill, where it has been observed with regularity over the past few months? It is hoped that the early stages can be recorded and conservation action taken to sustain the colony here in Singapore.

Text by Khew SK : Photos by Alan Ang, Federick Ho, Khew SK, Koh CH, Jonathan Soong, Tea Yi Kai and Alson Teo

References:


  • [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society
  • The Life Histories of Asian Butterflies Vol.1, Igarashi S. & Fukuda H., Tokyo University Press, 1997


27 January 2019

Return of the Angled Castor

Return of the Angled Castor
Angled Castor Colonises Ubin!


An Angled Castor perches on a blade of grass with its wings opened flat to sunbathe

Some time back in mid-Oct 2013, a solitary individual of the Angled Castor (Ariadne ariadne ariadne) was spotted in the Mandai forests in the northern part of the Central Catchment Area. Recorded as a re-discovery over 5 years ago, there were no further sightings of this species thereafter. Until recently, that is. Late last year, the Angled Castor was observed on Pulau Ubin.


A skittish Angled Castor beats a hasty retreat from its perch on a leaf of its caterpillar host plant, Castor Oil Plant (Ricinus communis)

Then there were more sightings of this species and the pristine condition of the individuals spotted suggested that they were not chance observations of seasonal migrants. This led to the theory that the Angled Castor had somehow managed to sustain a breeding population and that a colony of the species has established itself on Pulau Ubin.




A large grove of the Castor Oil Plant can be found on Pulau Ubin

Locating this colony was not too difficult, as the Angled Castor is not a rare species in Malaysia and Thailand, where the species can be locally common where it occurs. The key is to look for its preferred caterpillar host plant called the Castor Oil Plant (Ricinus communis). There is a site on Pulau Ubin where after clearance, the Castor Oil Plant grows in abundance.


An Angled Castor perched on a blade of grass in the early morning hours

When we visited this area on Pulau Ubin over the weekend, we found that a small colony of the Angled Castor had established itself in the vicinity of the host plants. A rough estimate of at least 30 adults and caterpillars were counted. Two adult female Angled Castors were even observed ovipositing on its host plant.



The leaves of the caterpillar host plant, Castor Oil Plant, reminds us of tapioca leaves

Firstly, let us consider the caterpillar host plant, the Castor Oil Plant. It has been described as an invasive species that colonises wastelands and cleared areas that have been neglected. It tends to form monospecific stands at the expense of other species of native plants and can displace other species due to its aggressive growth and the way the seeds can be distributed. In terms of plant biodiversity, it is considered an unwelcome "weed" that needs to be managed or eradicated.




Flowers, fruits and seed pods of the Castor Oil Plant

The Castor Oil Plant has a reputation of being a noxious weed and its seeds, if chewed and ingested, can have potentially fatal consequences to humans and animals. One deadly toxin, the notorious ricin is extracted from its seeds. Having been used as a terrorism weapon will not help its case! Furthermore, its commercial value of having the seed oil extracted for a variety of uses from cosmetics to lubricating oil and biodiesel does not exist in Singapore. Hence the plant faces the risk of being managed out of the eco-system in favour of other more useful plants.


A female Angled Castor ovipositing on the underside of a leaf of the Castor Oil Plant

Let us come back to the butterfly that depends on this plant of "ill-repute" for its survival, the Angled Castor. It is likely that a female of the species flew over from nearby Johor where it exists, and managed to oviposit on the host plants that grows on Ubin. That chance moment then started the next generations of individuals that now populate this area of Pulau Ubin.


An Angled Castor sunbathing on the top of a leaf

Besides the potential eradication of its caterpillar host plants, what are the other risks to the continued sustainability of the colony of this species in Singapore? Firstly, genetics should be considered. Will this very localised colony suffer from in-breeding and wipe itself out after a few generations? It is known that some species of butterflies are more vulnerable to in-breeding than others. If there are no new genetic material coming into Singapore from up north, can this colony survive?




Different instars of the Angled Castor's caterpillars found on the Castor Oil Plant on Pulau Ubin

What about predation? Given that the caterpillars and butterflies of this species are not known to be distasteful to birds and other predators, the delicate existence of this colony may also be wiped out by predation. The caterpillars are also in full view of areas with human activity and may be deemed as pests and eradicated.



Angled Castors appear to favour the flowers of this grass species for its nectaring source

Whilst observing the adult butterflies, they appear to be depending on their sustenance from the flowers of a particular species of wild grass. Several adults were seen feeding on the grass flowers. Other individuals were puddling on the damp muddy areas at the site. Whilst there are areas nearby with nectaring flowers, the Angled Castor has not been seen beyond the confines of this small area, nor to feed on other flowering plants so far.



The Angled Castor is the sole representative of the subfamily Biblidinae of the family Nymphalidae in Singapore. The butterfly is dark reddish brown with thin black squiggly lines on the upperside of its wings. There is a prominent white sub-apical spot on the upperside and underside of the forewing. The underside is a duller brown and similarly streaked with black lines but having a more 'banded' appearance in the darker areas between the lines.



The butterfly superficially appears like the Chocolate Pansy (Junonia hedonia ida) and is equally as skittish. Males of the Angled Castor have been observed to engage in 'dogfights', probably in their quest for territorial space. From our observations, the butterflies can fly for long periods of time with occasional stops to rest with their wings opened flat.



A newly-eclosed Angled Castor still hanging on to its pupal case

A puddling Angled Castor feeding on moisture along a footpath

At the Ubin site, several instars of caterpillars were found on a single host plant, suggesting that the eggs have been laid at different times over the past month or so. A newly-eclosed female was chanced upon, still hanging onto its pupal case. From the number of individuals observed this weekend - both pristine and tattered/weathered adults, it is obvious that the colony has been thriving at this location for the past few weeks, if not months.


An Angled Castor perched with wings folded upright, showing its undersides

For a species that is considered a "very rare" seasonal migrant to Singapore, it is now "very common" at this localised area on Pulau Ubin and from the breeding population, it can be now be assumed to be an extant species here. The status of various species can change from time to time, depending on circumstances and ecological and environmental changes that affect their existence in a country. It remains to be seen for how long this re-discovered species can continue to survive in Singapore, and whether natural or human-initiated threats affect this colony in the longer term.

Text by Khew SK : Photos by Khew SK, Loh Mei Yee and Tea Yi Kai.