29 August 2021

Butterfly of the Month - August 2021

Butterfly of the Month - August 2021
The Ultra Snow Flat (Tagiades ultra)

A pristine Ultra Snow Flat feeding at the flowers of the Pagoda Flower (Cleredendron paniculatum)

Someone recently remarked to me : "OMG! Is September around the corner already??". Yup. We had another month of "lockdowns", takeaway meals, WFH and the like. And almost another year that's been stolen from us by this COVID19. No travelling, no overseas work trips and a ton of leave to clear with nowhere to go. That's what life has become, as we try to imagine life after COVID - or rather, what life would be like, living WITH this virus around us. Already, the 3-digit daily infection numbers in Singapore seem to have lost its panic-inducing effect, and the general citizenry is slowly coming to terms with an "endemic" disease that we have to live with.

An Ultra Snow Flat feeding on the nectar of the Chinese Violet (Asystasia gangetica)

Somehow, the severe toll on certain businesses is expected, but not often openly publicised. There are hushed whispers of companies going under, salary cuts and retrenchments. But then again, there are still people who are leaving their present jobs. A strange phenomenon, but nonetheless true. Did the pandemic create an environment where workers have more time to reflect on what they really want to do? Or is there actually a manpower shortage out there which has created a demand that outstrips supply of manpower resources?

A sunbathing Ultra Snow Flat perching on the upperside of a leaf with its wings spread open flat

In the built environment industry, anecdotal information indicates that there are construction firms that are closing down, creating an even more critical demand for contractors and hence higher costs and long delays. Even the big boys are not spared. Projects are delayed, lives changed as Singaporeans have to forego plans to move into their much-anticipated new homes, costs escalating - resulting in more contractual disputes, and the list goes on. And yes, it's caused by an organism that is invisible to the naked eye!

In spite of these negative environment, there are areas of optimism. The Tokyo Olympics "2020" were finally held in 2021. Life for the athletes went on. Gold medals were won, and the display of sportsmanship and camaraderie of fair competition carried into the spirit of the Games. Someone grabbed the bull by the horns and decisively pushed on with the Olympics and in the blink of an eye, it is over. Done. COVID or no COVID, Japan moved on.

Over in Singapore, we celebrated Singapore's 56th year of independence. For the first time in history, the National Day celebrations were postponed. It was at the height of another surge in infections, as the government tried to move the vaccination programme forward - 60%, 70%, 80% of the population was fully vaccinated - day by day. Statistics also showed that people who were vaccinated but infected with the virus had milder symptoms or are able to recover better than those who were not. But there is a proportion of residents who are not vaccinated - either because they cannot be, or do not want to be.

But enough of the virus already. We turn to our Butterfly of the Month for August 2021 - the now moderately rare Ultra Snow Flat (Tagiades ultra). It was re-discovered in the 1990s and reinstated in the Singapore Checklist as extant. Perhaps due to its behaviour and shy nature, this species has often been elusive. But there have been regular sightings by nature enthusiasts and photographers in various areas across the island. It is certainly a resident species, as long as its caterpillar host plant, Dioscorea glabra is available.

The Ultra Snow Flat is one of four species of the genus Tagiades found in Singapore. Referred to as the "Snow Flats" the common name probably refer to the snowy white hindwings (except for the Common Snow Flat, which has bluish-white undersides) and the typical behaviour of the Pyrginae subfamily of skippers that stop with their wings opened flat.

They are often active in the cooler hours of the day, in the morning and evening, and can also be observed feeding at flowering plants for nectar. They can be spotted sunbathing on the tops of leaves in the early morning hours, but when the sun shines and warms up the environment, the Ultra Snow Flat then changes its behaviour and perches on the undersides of leaves with its wings spread open flat. And this is how many photographers encounter this species.

A rare underside shot of the Ultra Snow Flat with its wings folded upright

The Ultra Snow Flat is dark blackish-brown above with a series of hyaline spots on the forewing. The large dark submarginal spots on the hindwing can sometimes be conjoined and there is high variability in the sizes and arrangements of these spots. But there is always a full complement of spots at the whitened tornal area of the hindwing. On the underside, the white area is more extensive.

An Ultra Snow Flat feeding at the flowers of Syzygium zeylanicum
A typical underleaf pose of the Ultra Snow Flat

The species is a fast flyer and can be quite skittish. When alarmed, it zips away and hides on the undersides of leaves, usually closer to the ground. Even when feeding at flowers, the wings are spread open flat, such that there are very few field shots showing the underside of the Ultra Snow Flat, where it closes its wings upright.

The caterpillars of the Ultra Snow Flat feeds on the vine Dioscorea glabra on which it has been successfully bred in Singapore. The host plant is usually found in the forested nature reserves of Singapore where it creeps low amongst the shrubbery. The full documentation of the life history of this species can be found here.

Text by Khew SK : Photos by ChngCK, Federick Ho, Khew SK, Henry Koh, Koh CH, Loke PF, Jensen Seah, Horace Tan and Tan BJ.

07 August 2021

Life History of the Spotted Flitter

Life History of the Spotted Flitter (Zographetus doxus)

Butterfly Biodata:
Genus: Zographetus Watson, 1893
Species: panormus Eliot, 1959
Wingspan of Adult Butterfly: 30-32mm
Caterpillar Local Host Plant: Vitex pinnata (Lamiaceae/Labiatae, common names: Leban, Malayan Teak, Vitex, Halban, Leban Buas, Leban Papa, Leban Tandok).

A male Spotted Flitter.

A male Spotted Flitter.

A female Spotted Flitter.

A female Spotted Flitter.

Physical Description of Adult Butterfly:
On the upperside, the wings are dark brown with hyaline sub-spaical yellowish spots on the forewing. On the underside, the hindwing discal area is yellowish in the male and the entire underside is mostly yellow in the female. Dark brown discal and post-discal spots are also featured on the hindwing. Both wings have brown marginal bands. The annennae of the male are broadly whitened just after the apiculus (the hooked tip at the end of the club antenna), while those of the female has a much reduced white patch at the tip of the apiculus.

A short video clip showings the adult stage of the Spotted Flitter.

Top view of two Spotted Flitters. Left: male; Right: female. Note the difference in the antennae.

An upperside view of a male Spotted Flitter perching on a palm leaf.

A female Spotted Flitter.

A male Spotted Flitter perching on a palm leaf.

Field Observations of Butterfly Behaviour:
The Spotted Flitter is rare in Singapore. Its occasional sightings range from urban parks and gardens to forested areas in the nature reserves. The adults are usually observed in the early morning hours of the day or in deep shady areas during later hours. The adults are fast flyers as is typical of most skipper species.

A male Spotted Flitter.

A male Spotted Flitter.

A female Spotted Flitter.

A female Spotted Flitter.

Early Stages:
Thus far only one local host plant, Vitex pinnata, has been recorded for the Spotted Flitter. This plant is a tree of the family Lamiaceae, and it can grow up to a height of about 25m. Typically caterpillars of the Spotted Flitter are found on young plants 1 to 2m in height. The leaves of the Vitex pinnata are palmately compound with sessile leaflets. The caterpillars of the Spotted Flitter feed on the mature leaves in all instars, and live in leaf shelters constructed at leaf edge.

Local host plant: Vitex pinnata.

A female Spotted Flitter laying an egg on a leaf of the host plant growing at a forest edge.

The eggs are laid singly on a leaflet of the host plant, typically on the upperside. Each dome-shaped egg is dark red with 14 to 16 whitish longitudinal ridges, and has a beige brown pitted donut-shaped cap. The egg is rather large with a diameter of about 1.4-1.5mm.

Two views of an egg of the Spotted Flitter, diameter: 1.4mm.

It takes about 6 days for the egg to hatch. The fully developed egg is orange in colour with the back head capsule is visible through the egg shell.

Left: fully developed egg with the polar portion eaten and the head of the caterpillar visible. Right: empty egg shell left behind after the exit of the caterpillar.

The young caterpillar eats just enough of the shell to emerge. Unlike most other butterfly species, the newly hatched of the Spotted Flitter does not proceed to devour the empty egg shell. The newly hatched has a length of about 2.5mm. Its orangy 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 dark brown with a black collar lying behind it on the prothorax.

A newly hatched caterpillar of the Spotted Flitter, length: 3.5mm.

After emerging from the egg shell, the newly hatched caterpillar constructs its first leaf shelter, typically at the nearby leaf edge. With diligent lamina cutting and use of silk threads, the leaf shelter gradually takes on a gobular appearance, a rather unique shape for leaf shelters of skipper species. The 1st instar takes a total of 3.5-4 days to complete with body length reaching about 4.5mm.

A newly hatched caterpillar of the Spotted Flitter in the partially constructed first leaf shelter.

Two views of a completed leaf shelter, note the gobular appearance. Left: top view; Right: side view.

Two views of a 1st instar caterpillar, late in this stage, length: 4mm.

The body of the 2nd instar caterpillar is dark orangy brown with a dark brown head. The body and the head are covered with numerous tiny whitish setae. The dark brown collar on the prothorax is still present. This instar lasts a total of 3.5-4 days with the body length reaching up to 6.5mm.

Two views of a 2nd instar caterpillar, early in this stage, length: 4mm.

Two views of a 2nd instar caterpillar, length: 5.5mm.

A leaf shelter of a 2nd instar caterpillar of the Spotted Flitter.

Two views of a 2nd instar caterpillar, length: 6mm.

The 3nd instar caterpillar resembles the 2nd instar caterpillar closely. The body takes on a more distinctly mottled appearance as there are whitish specks at the base of each tiny setae careting the body surface. This instar lasts about 4-5 days with the body length reaching up to about 9.5mm.

A newly moulted 3rd instar caterpillar with the color of the head yet to darken to dark brown. The exuvia is right next to the caterpillar.

Two views of a 3rd instar caterpillar, length: 8.2mm.

Close-up view of the body face of an early 3rd instar caterpillar.

Two views of a 3rd instar caterpillar, late in this stage, dormant prior to the moult to the next instar.

The 4th instar caterpillar resembles the 3rd instar caterpillar closely. Its body colour ranges from yellowish brown to orangy brown. To accommodate the increased body size, the caterpillar enlarges its leaf shelter with more skillful cutting of lamina and use of silk threads. This instar lasts 6-8 days with the body length reaching up to 14.5mm.

A newly moulted 4th instar caterpillar, adjacent to its exuvia. The head is yet to darken to the dark brown colour.

Two views of a 4th instar caterpillar, early in this stage,  length: 9mm.

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

Two views of a leaf shelter of a late instar caterpillar of the Spotted Flitter.

The 5th instar caterpillar does not differ much from the 4th instar caterpillar, except for the more distinctively mottled appearance due to the increased size of the numerous whitish spots covering the body surface.

Two views of a 5th instar caterpillar, early in this stage, length: 14mm.

Two views of a 5th instar caterpillar, length: 22mm.

The 5th instar takes about 8 days to complete with the body length reaching up to 28-29mm. In the last 2 days of this instar, whitish powdery substance appears on the ventral surface of the caterpillar. The caterpillar also abandon the brownish gobular leaf shelter, and proceed to a leaflet to start constructing the pupation shelter. It also nearly sever the petiole and midrib at multiple points and secure the resulted parts with silk threads. The leaf shelter is formed by cutting the leaf lamina to create two adjacent folds and having two ends of a fold tucked in to form an almost enclosed space. The completed leaf shelter roughly takes on a submarine shape.

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

Close-up view of the body surface of a late 5th instar caterpillar.

Two views of a 5th instar caterpillar, with body color changes prior to becoming a dormant pre-pupa.

Within the pupation shelter, the body has its color changes to pale yellowish brown. The caterpillar also excrete a fair amount of whitish powdery substance which cover its body as well as the inner wall of the shelter. This prepupatory phase lasts for 1-1.5 days.

A pupation shelter of the Spotted Flitter.

The pupation shelter shown above opened to reveal  a pupa of the Spotted Flitter.

Pupation takes place within the pupation shelter. The resultant pupa is secured to the inner wall of the shelte with a cremastral attachment. The pupal body is brown in the thorax and wing pad areas, but yellowih brown in the abdomen. With the pupaion almost closed, the shedded head and exuvia of the 5th instar are left at the posterior end of the pupa. Length of pupae: 17-18mm.

Two views of a pupa of the Spotted Flitter, length:24mm

After about 8 days, the pupa becomes mostly dark brown with the wing pad areas in darker brown and a glimpse can be caught of the spots present on the forewing upperside. Eclosion takes place the next day.

Two views of a fully developed pupa of the Spotted Flitter, with the adult butterfly ready to emerge within minutes.

A male Spotted Flitter emerges from its pupal case.

Another male Spotted Flitter emerges from its pupal case.

A newly eclosed male Spotted Flitter.

A newly eclosed female Spotted Flitter.

  • [C&P5] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, G. and N.  van der Poorten (Eds.), 5th Edition, Malayan Nature Society, 2020.
  • 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 Loh Mei Yee, Loke PF, Frederick Ho, Khew SK and Horace Tan; Videos by Loh Mei Yee and Horace Tan.