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.

References:

• [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.

Butterfly of the Month - July 2021

Butterfly of the Month - July 2021

The Common Sailor (Neptis hylas papaja)

A Common Sailor feeding on the ripened fruit of the Singapore Rhododendron (Melastoma malabathricum)

We are well into the 2nd half of 2021, as the world is beginning to reach a limit with pandemic fatigue. Some governments are beginning to consider treating the virus as "endemic" and living with it will be what we may have to contend with, in the near future. After all, how many more lockdowns, quarantines and movement restrictions can the populace take?

A Common Sailor perched with its wings opened flat to sunbathe.  Note the metallic green sheen on its thorax when viewed from above.

As vaccination programmes reach a certain critical number, some jurisdictions are planning to relax various restrictive measures. For example, face-masks may be dispensed with, or movement controls and safe distancing relaxed when a benchmark percentage of the population has been fully vaccinated. The many restrictions, safety measures and movement controls have already taken their toll on many economies all around the world , with some companies facing imminent and permanent closure.

Over in Tokyo, the Japanese government appeared to have taken the COVID19 bull by the horns and decided to proceed with the "2020" Tokyo Olympics in 2021. Perhaps the motivation behind the decision to proceed to hold the Olympic games could be economic rather than prudence. But here it is, the Games have begun, but with most spectators watching online and stadiums and games venues largely empty. However that does not take away the glory from the athletes who achieve the podium positions in their respective sports.

Back home in Singapore, the resurgence of the Delta variant in KTV lounges sparked off another round of restrictions in the community. This was followed by several other clusters emerging from a wholesale centre, which then moved to public wet markets. In just a few days, the numbers of new infections hit three-digits and disrupted the progress of opening up. Dining out in public places is no longer allowed until mid-August as the government rushes to vaccinate the population.

A classic pose of the Common Sailor perched on a blade of lallang

Already the Singapore government is debating on the possibility of "opening" up and living with the virus as if it were just the common influenza. Data collected and findings that show that fully vaccinated infected individuals have mild symptoms or even asymptomatic, has given optimism that it may one day be possible to take COVID19 in our stride as an endemic disease that is no longer life-threatening. We look forward to that day!

Our feature butterfly for July 2021 is the Common Sailor (Neptis hylas papaja). This butterfly is one of the four Sailor species found in Singapore - three from the genus Neptis, and one from Phaedyma. The Common Sailor is one of the black-and-white lookalikes and sometimes confused with the Burmese Sailor or Short Banded Sailor. However, when the butterfly is at rest, there are distinguishing characteristics in the markings that will separate the lookalikes.

The Common Sailor has a distinctive weak flap-glide-flap flight that separates it from the related but similar looking Sergeants (Athyma spp) that have a more powerful and robust flight. The Common Sailor is widely distributed in Singapore, being found in urban parks and gardens as well as the forested nature reserves and our offshore islands.

The species has a black and white striped upperside. The forewing white cell streak is usually interrupted by a thin black line towards the cell end. The underside of both wings is a rich golden brown. The white stripes are distinctly outlined in black and this is one of the distinguishing attributes of this species to separate this species from its lookalike cousins.

A mating pair of Common Sailors

The eyes of the Common Sailor are transparent and the compound eyes are bluish grey.  On the upperside of the thorax, there is an iridescent greenish-blue sheen. Its abdomen is not white-ringed next to the white discal band on the hindwing.  Its antennae clubs are usually orange-yellow tipped.

A Common Sailor feeding on the ripened fruit of the Singapore Rhododendron (Melastoma malabathricum)

The caterpillars of the Common Sailor feed on a variety of host plants, all from the Fabaceae family. The local host plants on which the species has been successfully bred are : Calopogonium mucunoides, Canavalia cathartica, Aeschynomene americana, Senna alata, Psophocarpus tetragonolobus and Centrosema molle.

Text by Khew SK : Photos by Khew SK, Loh MY, Tan BJ and Anthony Wong