The Predator Strikes Back!

The Predator Strikes Back!

(And the Rebels that Got Away)

A female Autumn Leaf showing evidence of a predatory strike

Contrary to what the title of this week's blog article may suggest, no, you won't get to hear stories about things that happened a long, long time ago in a galaxy far, far away. Or see pictures of Yoda or Darth Vader. This is still a butterfly blog, and we are still talking about butterflies. :)

A Commander with its right hindwing damaged : Predatory strike or wear and tear?

If you're also wondering what happened to spectacular photos of pristine and beautiful butterflies that this blog has become known for, this week's article is about strikes - predatory strikes and 'scars' of attacks on butterflies. In nature, butterflies are subject to dangers of all shapes and sizes in the form of predators whose sole objective is to eat the poor butterflies. In my earlier articles about predators (see : Death in the Wind), we featured a whole range of predators that feed on butterflies.

In this article, we show the embattled ones that "got away" with souvenirs of chipped, torn and badly damaged wings that these butterflies suffer from predatory strikes. In earlier articles discussing survival strategies, we had also shown how butterflies have tried to even the odds by employing the use of various 'tricks' to fool predators into either not noticing them altogether, or biting off a part of the wings that are less critical. (See Survival Strategies Part 1 and Part 2)

This invariably allows the victim of a predatory attack to escape alive, albeit without a portion of its wings intact. The surviving butterfly will be "crippled" but buys a few more hours or perhaps days of continued survival to either mate or lay eggs, and allowing it to fulfil its ecological function of procreation of the species.

A Great Mormon with a significant part of its left hindwing torn off by probably a predatory strike

Field observations by ButterflyCircle members have contributed valuable information and photographic records of predatory attacks on butterflies. Whilst there are no conclusive evidence of the type of predator that attacked these butterflies, the damage on the wings could give some forensic clues to the types of strikes that the butterflies had encountered.

The same individual of the male Great Mormon using its forewings to continue to fly and feed

For those butterflies with a symmetrical tear on both wings, a likely predator would be birds, that had tried to take a bite at the victims, but obviously missed delivering a fatal strike. The escaped butterfly continues to go about its daily business, but without a part of its wings. It is quite amazing to consider how much wing material is removed, before the butterfly it totally crippled and unable to fly.

In spite of its aposematic colours, this female Malay Lacewing is not spared a predatory strike

Despite the damage, many of these predator-struck butterflies appear to be still able to fly relatively 'normally'. However in some cases, the ability to shift into high gear and take off at their usual speeds is drastically reduced, suggesting that a 2nd attack by a predator would most likely be fatal. Furthermore, the erratic flight of the damaged butterfly would also call attention to itself and the weakened flight would almost certainly attract nearby predators to attack a "sitting duck".

A "one-armed" Commander with its left forewing substantially bitten off

In cases where the wing damage is asymmetrical, e.g. only one side of the wings are torn, it could suggest that the butterfly was sunbathing with its wings opened flat, and the predator managed to take a chunk off one wing as it struck but missed. However, it will be almost impossible to conclude if the predator was a bird, a lizard, a shrew or any other attacker with mouth parts large enough to take a piece off the butterfly's wing.

The typical behaviour of the butterfly species is also quite consistent with the types of damage on the wings. For example, a ground lurker like the Ypthima species are more likely to be attacked by a reptile whilst it is sunbathing on a low bush. Some field examples tend to show asymmetrical bite marks on one side of the wings only.

A Dark Blue Jungle Glory with a symmetrical bite mark on its hindwings

For a Dark Blue Jungle Glory, that spends most of its day foraging amongst litter on the forest floor, its most likely attacker would be a snake, lizard or a small mammal?

The fast flying Blue Jay that shows hindwings that bear evidence of a predator strike

Even the "turbo-charged" butterfly species, that are usually skittish and fly at tremendous speeds, are not spared predatory attacks. Despite their propensity for high-speed flights and alertness, no butterfly can continue to do so all the time. When they come down from lofty perches to rest or feed, that is when a lurking predator has an opportune time to launch a strike at the butterfly.

Where are my light sabres? A "swordless" Five Bar Swordtail - a probable victim of a predator strike

Examples shown here, are two fast flying Paplionidae species, where under normal circumstances are very alert and skittish, and rarely give any chances for predators to chase and attack them when in full flight. However, it is likely that their torn hindwings are examples of predatory strikes that occur when they were at rest or puddling.

The near-symmetrical bite marks on these two different Flash species suggest a predator attacking the "wrong" side of the butterfly allowing it to escape alive

The Lycaenidae, which employ decoy tactics whereby a predator is fooled into attacking a less vital part of its wings, often show evidence that this survival strategy does work quite successfuly in the field.

Two Lycaenids with their tornal areas bitten off

We have come across quite a number of individuals that display scars of such attacks, where the hindwings are torn in a symmetrical manner, suggesting that the predator had been fooled into attacking the "wrong" side of the butterfly where its false eyes and antennae are located.

Can this poor Peacock Pansy actually still fly?

Yet other species, which feature eyespots and rings on their hindwings, appear to also show signs of attacks on the parts of their wings where the false eyes are located. Again, in the shown example of the Chocolate Pansy below, a large part of the hindwings has been bitten off, yet it continued to fly and glide quite normally... until the next (and probably fatal) strike occurs.

The near symmetrical tear on both the hindwings suggest a predatory strike when the butterfly was resting with its wings folded upright

And so we see a part of the daily survival of a butterfly, whose life is always fraught with dangers of being a lucky predator's lunch (or not), and how it manages to escape with its life to "fight" for another day. Whilst the exact nature and the actual predator cannot be easily concluded from these pictures, they show some evidence where the clues help to piece together some possible theories as to what attacked these butterflies.

Even this fast-flying Common Snow Flat shows damaged hindwings. Evidence of predatory strike? Or just damage caused by old age?

Text by Khew SK ; Photos by Chng CK, Federick Ho, Khew SK, Loke PF, Horace Tan & Yano

Special Acknowledments to Teo TP for sharing research papers on predator strikes & behaviour ; William Folsom for starting a discussion on this topic on ButterflyCircle's forums

Life History of the Dark Tit

Life History of the Dark Tit (Hypolycaena thecloides thecloides)

Butterfly Biodata:
Genus: Hypolycaena C & R Felder,1862
Species: thecloides C & R Felder,1860
Sub-species: thecloides C & R Felder,1860
Wingspan of Adult Butterfly:26-30mm
CaterpillarLocal Host Plant: Flagellaria indica (Flagellariaceae).

A sunbathing  Dark Tit  displaying its upperside.

Physical Description of Adult Butterfly:
Above, both sexes are dark brown except for an orange tornal area stretching to space 3 on the hindwing. Prominent black spots are embedded in the orange tornal area in spaces 1b and 2 and within the whitish area in space 1a. Underneath, both sexes are whitish grey with  acell-end bar and a narrow orange post-discal line on both fore- andhindwings.  The forewing apical area, costal margin and termen are shaded in orange.The hindwing has an orange tornal area up to space 3 and a prominent black spot embedded in space 2. Another equally large black spot is featured on the whitish tornal lobe. A prominent orange bar could be found at the base of space 7 in the hindwing. There are two white-tippedtails at ends of veins 1b and 2, with the longer one at vein 1b. Theupperside of the abdomen is colored as per wing upperside, but theunderside is mostly white. The legs are also whiteand black-banded.

Field Observations of Butterfly Behaviour:
This species is moderately rare in Singapore. It can be found in the Central Catchment Reserve, certain wastelands as well as  landward edges of mangrove areas in both the main Singapore island and offshore islands like Pulau Ubin and Pulau Semakau. At times, the adults have been found to  occur in numbers locally at one location. The fast flying adults typically perch with its wings closed upright between flights. In sunny weather, however, they have the tendency to sun-bathe with wings fully open.

Early Stages: 
The Dark Tit is likely to be monophagous as only one host plant has been recorded both locally and across the region. Its host plant, Flagellaria indica, is  a monocotyledon. This is  remarkable  as the majority of  Lycaenidae species feed on dicotyledons.  Also noteworthy is that the same host plant is recorded in Igarashi and Fukuda's voluminous work: Life History of Asian Butterflies, vol. 2, but with the plant wrongly identified as a gramineae species. The caterpillars of the Dark Tit feed on the leaf blades and young/immature stems of the host plant, and  are attended by several ant species.

Host plant: Flagellaria indica.

Three eggs of the Dark Tit found on the host plant in a wetland reserve.

The eggs are laid singly on leaf underside or on the stem of the host plant. Each egg is about 0.7-0.75mm in diameter, white in color with a greenish undertone when freshly laid. It is dome-shaped with a depressed micropylar at the pole.  Large triangular  indentations with rather broad ridges are featured on the egg surface.

Two views of an egg of the Dark Tit.

A sequence of 4 snapshots  of egg development.
 
It takes about 3 days for the egg to hatch. The pale yellowish brown newly hatched has a length of about 1-1.1mm. Its head and the rather large pro-thoracic shield are in the same coloration as the body ground colour. The body also features rather long, pale yellowish brown  dorso-lateral and lateral setae (hair).  The newly hatched shows no interest in devouring the remnant of the egg shell after its emergence, and moves straight away to nibble on the leaf lamina in its vicinity. The caterpillar typically leaves a feeding trail  marked with foliage/tissue damage and frass pellets.

Two views of a newly hatched caterpillar of the Dark Tit.

An early 1st instar caterpillar  feeding  on the stem of its host plant (near center of pic).

As it grows, the body color becomes more yellowish.  After about 3-4 days of growth in the first instar, and reaching a length of about 2.4mm,the caterpillar moults to the next instar. Unlike its  cousin, the Common Tit (Hypolycaena erylus teatus), the Dark Tit caterpillars consume the exuvia after each moult.

Two views of a 1st instar caterpillar, late in this stage, length: 2.3mm.

Two views of a 1st instar caterpillar, dormant before its moult.

The 2nd instar caterpillar has numerous pale brown setae over its body, with those occurring dorso-laterally and laterally somewhat longer than the rest. Depending on whether it is feeding on the yellowish brown stem or the green leaf blades, the caterpillar appears to occur in two colour forms: yellowish brown throughout or yellow with a strong green undertone.  Even at this early stage, the dorsal nectary organ is discernible on the dorsum of the 7th abdominal segment. The 2nd instar caterpillar reaches a length of about 4.5-4.8mm, and after about 3 days in this stage, it moults again.

Two views of a 2nd instar caterpillar, early in this stage, length: 2.2mm..

Two views of a 2nd instar caterpillar, late in this stage, length: 4.2mm.

Two views of a 2nd instar caterpillar, dormant before its moult, length: 4.1mm.

The 3rd instar caterpillar resembles the 2nd instar caterpillar closely. One discernible difference is that the numerous setae covering the body are now proportionately shorter and uniform in length. The dorsal nectary organ is also rather large and  prominently featured. However the pair of tentacular organs found on the 8th abdominal segment in most of the other Lycaenidae species are not observed in the Dark Tit, in this and later instars. The 3rd instar takes about 2-3 days to complete with the body length reaching about 6.5mm.

Two views of a 3rd instar caterpillar feeding on the stem tissue, length: 5.5mm

Two views of a 3rd instar caterpillar, late in this stage, length: 6.2mm.

The 4th instar resembles the late 3rd instar caterpillar closely with no obvious changes.  The 4th instar takes about 3 days to complete with the body length reaching about 11mm.

Two views of a 4th instar caterpillar, early in this stage, length: 6.5mm.

Two views of a 4th instar caterpillar, late in this stage, length: 10mm.

A Dark Tit caterpillar feeding on the stem of the host plant.
Note the attending ant and the pile of frass pellets.

The 5th instar caterpillar is again little changed in body features from the earlier two instars. In comparison, its body colour is mainly green. Its dorsal nectary organ seems to be rather  active with droplets of nectary fluid being exuded from time to time.

A newly moulted 5th instar caterpillar of the Dark Tit.

Two views of a 5th instar caterpillar, length: 13.5mm.

Two views of a 5th instar caterpillar, late in this stage, length: 17mm.

A 5th instar caterpillar devouring stem issue in a wetland reserve. Note the attending ant and the fluid droplet on the dorsal nectary organ.

After about 3 days of feeding and reaching a length of about 17mm, the caterpillar stops foodintake, and its body gradually shortened and decolorised to a uniform lime green.  The caterpillar would wander around in seek of a pupation site which is typically a spot on the leaf surface. At this site, the pre-pupatory caterpillar prepares for pupation by spinning a silk girdle and a silk padto which it attaches itself via its anal claspers.  After 1 day as apre-pupa, pupation takes place. The pupa has a typical but stout Lycaenid shape. It is predominantly pale greenand unmarked. Pupal length: 8.5-10mm. 

Two views of an immobile pre-pupa of the Dark Tit.

Two views of a pupa of the Dark Tit.

Seven days later, the pupa turns rather dark, first in the wing pad and thorax,then progressively in the abdomen. The next day, the pupal stage comes to an end with the emergence of the adult butterfly.

Two views of a mature pupa of the Dark Tit.

A newly eclosed  Dark Tit waiting for its wings to expand fully near its pupal case.


References:

• [C&P4] The Butterflies of The Malay Peninsula, A.S. Corbet and H.M. Pendlebury, 4th Edition, The Malayan Nature Society.
• Life Histories of Asian Butterflies, Volume 2, S. Igarashi & H. Fukuda, Tokai University Press, 2000.
• Butterflies of Thailand, Pisuth Ek-Amnuay, 1st Edition, 2006.

Text by Horace Tan, Photos by Wong C M, Loke PY, Chng CK, Nelson Ong  and Horace Tan

Send in the Clowns!

Send in the Clowns!
Discovery of the Common Jester (Symbrenthia hippoclus)


A puddling Common Jester first shot on 18 Feb 2012

One late Saturday morning, ButterflyCircle member Federick Ho took a break from his work and took his photographic gear and went out for a couple of hours of butterfly hunting. After walking for some distance and shooting the usual butterflies that he encountered, he noticed a black and orange striped butterfly puddling on a concrete driveway. As he approached it, Federick took the usual "insurance" shots from afar. As he moved closer for a better shot, the butterfly took off speedily and headed for the treetops. Assuming that it was either a Lascar or a Colour Sergeant, Federick didn't think much of his record shot and stored his camera equipment as the dark clouds signalled an imminent downpour.

Later in the week, when Federick processed his shots, he realised that he had shot something new! Upon closer examination, it was concluded that this was one of the Jester species from the genus Symbrenthia. This sparked off a search for this mystery butterfly the following Saturday, but a whole morning of searching the area where Federick last saw this butterfly was in vain. Glimpses of some black and orange butterfly gliding around were made, but the Jester proved elusive.

Undeterred, senior ButterflyCircle member Sunny Chir went again the following day to look for it. Based on the knowledge that the Symbrenthia spp were mainly forest species, Sunny decided to hunt in the nearby forested area where the species was last shot. After a long hot trek looking high and low for the butterfly, Sunny spotted a small colony of individuals of the Jester-like butterflies gliding at the treetops. He waited patiently and an individual flew down, and Sunny was able to take a shot of its underside.

A 2nd individual of a Common Jester shot on 26 Feb 2012

There are four species of the genus Symbrenthia recorded from Malaysia. All the species bear a short pointed tail on the hindwing. The Symbrenthia or Jesters, are black above with orange bands. The undersides are a richly coloured with variegated patterns on a buff or ochreous ground. Initial examinations of the photographs taken by Federick and Sunny indicate that this new discovery for Singapore is most likely a Symbrenthia hippoclus selangorana or referred to by its English Common name, the Common Jester.

ButterflyCircle records this officially as species #302 in the Singapore Butterfly Checklist and a new discovery for Singapore. We welcome this new "clown" in town, as the name Jester suggests, to our little island in the sun!

Text by Khew SK : Photos by Federick Ho & Sunny Chir

Butterfly of the Month - February 2012

Butterfly of the Month - February 2012
The Pointed Line Blue (Ionolyce helicon merguia)

The month of February 2012 is well upon us now, as we head towards the last day of the 29th day of this once-in-every-four years affair for February. This year, 2012, has 366 days instead of the usual 365 days, because of the additional day in February.

A leap year (or intercalary or bissextile year) is a year containing one additional day (or, in the case of lunisolar calendars, a month) in order to keep the calendar year synchronized with the astronomical or seasonal year.

In the British Isles, it is a tradition that women may propose marriage only on leap years. I presume that, in the first instance, the woman has to catch her man first, before doing so. In the cartoon below, the unsuspecting gentleman is as vulnerable as a butterfly sitting and enjoying itself, before the collector's net slams down on it!

Source : Wikipedia 1908 Description: "In 1908 / 'Be Careful, Clara, that's a fine Specimen!'"

Two more observations about leap years - (1) that a leap year will give a full number result if you divided the year by 4, whilst doing so with other years would give you an additional fraction remaining. Also, (2) the Summer Olympics (this year in London) will always also fall on a Leap Year.

The first two months of the year has been rather quiet in Singapore. Other than the 15-day Lunar New Year festivities that were largely over by early February, and Valentine's Day on 14th of February, it had been relatively uneventful for most of us. But a lesson learnt from recent local developments that set social media networks ablaze and coffee-shop gossip, if you want to indulge in extra-marital affairs, stay out of the Singapore civil service and political parties. :)

A flower of a Viola sp. cultivar

The birth flower of the month for February is commonly associated with the Violet. Botanically referred to as Viola spp., (family Violaceae) the Violet is a flowering plant with heart-shaped leaves that often has a purple or blue to it. Essentially a temperate region plant, it prefers cooler climates.

Violet flowers are formed from five petals; four are upswept or fan-shaped petals with two per side, and there is one broad, lobed lower petal pointing downward. Flower colours vary in the genus, ranging from violet, as their common name suggests, through various shades of blue, yellow, white, and cream, whilst some types are bicolored, often blue and yellow.

Our butterfly for February 2012, the Pointed Line Blue (Ionolyce helicon merguia), also features a violet/purple blue colour particularly in the males. A small butterfly with a wingspan of under 30mm, it is a relatively common species and the only member of the genus Ionolyce to occur in Singapore.

It appears in urban parks and gardens as well as forested areas of the nature reserves. It is a fast flyer and flies erratically, sometimes up to treetop levels. The wings of the male of this species are more angular than the closely related Nacaduba.

The male Pointed Line Blue is deep purple blue on top with a very thin black margin but otherwise unmarked. The female is brown on top with the discal area of the forewing and both basal areas lightly overlaid with bluish purple. In addition, hindwing has a series of dark spots along the wing margin. Underneath, they are both dull brown with narrow whitish wavy lines. There is an orange-crowned eye spot and a filamentous tail at vein 2 of the hindwing.

A newly eclosed female Pointed Line Blue

On hot sunny afternoons, the males of this species are observed to engage in aerial "dogfights". They fly rapidly from their favourite perches, and often stop and open their wings flat to sunbathe, displaying their spectacular violet-purple uppersides.

More often than not, the species is encountered puddling at damp spots in the nature reserves with wings folded upright. Females are much rarer, and found feeding on florets of flowering bushes. They also resemble the Nacaduba species and can easily be confused with similar lookalikes from this other genus of butterflies.

And we end this article by wishing a Happy Birthday to all the special people whose birthdays fall on the 29th of February, and who technically celebrate their birthdays only once every four years!

Text by Khew SK : Photos by James Chia, Sunny Chir, Kenneth Er, Khew SK, Koh CH, Nelson Ong, Horace Tan, Mark Wong, Wong CM, Benjamin Yam & Zhuang YY