Wednesday, November 20, 2013

Endemic Butterflies of Sri Lanka

Butterflies are day-flying insects of the order Lepidoptera. The order Lepidoptera is the second largest insect order in Sri Lanka with over 2160 species. At least 195 of them are true Butterflies and 50 are Skippers, rest being macro and micro Moths. Sri Lanka is home to 245 species of butterflies with 23 of these being endemic to the island.

General Distribution
The majority of species are found in the foothills up to 3,000 feet elevation. A much smaller number of species are found above 4,000 feet while 20 species of butterfly are restricted to the low lying dry zone below 500 feet elevation. A majority of endemic species are restricted to the wet zone forests. The number of butterflies peaks in two seasons during the year. The first of these is during the Southwestern monsoon in the months of March to April. The second is during the Northeastern monsoon which continues from September to October.

General Threats and Conservation
Habitat destruction and degradation, air pollution, over-usage of pesticides, and over-exploitation for ornamental trade are the main threats to butterflies in Sri Lanka. Prolonged droughts and over-predation also pose a threat to them. Opportunistic predators such as ants and birds prey on butterfly eggs, caterpillars, pupae and adult individuals. The Sri Lankan Rose and Sri Lankan Birdwing species are presently included in the appendices of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). This United Nations initiative aims to protect these species against over-exploitation by restricting trade across borders.

1. Sri Lankan Birdwing
Scientific Name – triodes darsius
Family – Papilionidae
This is the largest butterfly in the country and also the national butterfly of the island. This is a forest lover but visits open areas of home gardens where nectar plants and its host plant Aristolochia (Sap Sanda) grow. It is frequently visible in riparian forest as well as open scrublands. It is not so uncommon throughout the island although it is mostly observed in the wet zone. Its large forewings are glossy black and hind wings bright yellow with a black margin. It has a quite slow wing beat but the flight is moderately fast as its wings are larger with an expanse of about 165–175 mm. Its status is listed as Near-Threatened by the IUCN.  

2. Sri Lankan Rose
Scientific Name – pacliopta jophon
Family – Papilionidae
It was earlier classified as a subspecies of Crimson Rose (Pachliopta hector) but now it is considered endemic to Sri Lanka. It is confined to the central hill country and is considered a globally threatened species due to the loss of habitat. The male upperside is black. The fore wing has three or four broad white streaks in a cell and a variable number of similar somewhat broader streaks. The hind wing too has white streaks with crimson lunules irrorated with black scales. The underside is similar, the markings more distinct and more sharply defined. This is totally a forest butterfly but visits open areas where nectar plants grow. It has quite a slow wing beat and the flight is slower compared to other Pachliopta species. It comes down to feed nectar early morning and late afternoon. Its status is listed as Critically Threatened by the IUCN.

3. Ceylon Tree Nymph
Scientific Name – idea iasonia
Family – Nymphalidae
The Ceylon Tree Nymph is a species of nymphalid butterfly in the Danainae subfamily. First described by John Westwood in 1848, the Ceylon Tree Nymph can be found in both wet and dry zones of Sri Lanka. It is the largest member of the Danaidae family in the country with a wingspan of 110–155 mm. Both its wings have similar patterns which are of a translucent silvery white color. The forewings are almost twice as long as their width. The female is larger in size than the male, and the males have narrower forewings than the females. The surface area of The Ceylon Tree Nymph's wings is relatively large when compared with its weight; this allows it to fly with little effort and stay aloft for long periods of time.

There are two populations of the Ceylon Tree Nymph. The smaller and darker colored variety is found in the wet zone of Sri Lanka from sea level to about 5,000 feet (1,500 m).They usually inhabit the sub canopies of lowland tropical rain forests. The other variety, which is larger and lighter colored, is found in the low country dry zone. They are usually encountered near water courses. Since the Ceylon Tree Nymph requires very little effort to fly its wing beats are very slow, so slow that the individual movements of each wing can be easily observed. Most of its time is spent flying and hovering in the high tree canopies. However, it descends to ground level to feed and to breed but does not rest on the ground. It usually rests on the ends of dead branches or twigs. It is listed as Near Threatened by the IUCN. The main threat faced by the Ceylon Tree Nymph is the destruction of its habitat. Several of its naturally occurring areas are protected areas, such as the forest reserve of Sinharaja.

4. Ceylon Tiger
Scientific Name – parantica taprbana
Family – Nymphalidae
The Ceylon Tiger is also a species of the Danainae subfamily. It has a wingspan of about 80-90 mm. The color patterns of sexes are similar. The upper surface of both wings is rich in dark chocolate brown with bright greenish white markings. The forewings have two distinct streaks starting at the base of the wings and the hind wing has similar markings. Both upper wing surfaces have a number of rounded spots towards the outer margins. The markings on the underside correspond to those on the upper surface but are lighter in color.

It is restricted to central mountain forests above 3000 feet on top of Pidurutalagala. It occasionally strays into the gardens of tea plantations. It is noticeably faster flier than any other Danaid. It flies commonly near to tree canopy and get nectar on wayside flowers. It hangs on the flowers at an incline with wings partly open while feeding. It flies lazily along pathways and roadsides. Not easy to approach and will fly away albeit slowly at any sudden movement. At very sunny days this species used to be seen flying slowly about the flowers in parks.

5. Cingalese Bushbrown
Scientific Name – mycalesis rama
Family – Nymphalidae
This satyrid butterfly has a wingspan of about 56 mm. Its wings are dark brown on the upper side, with two eyespots at the sub marginal area of the wings. The lower eyespot on the forewing is prominent and circled with orange, while the others are rather faint. The underside is dull orange brown, clearly distinguishing it from other Bushbrowns. It is rare and can be found near bamboo jungles in the low country wet zone. Their larva feeds on plants of the family Poaceae such as Bamboo. Though its flight is weak like other Bushbrowns, it flies at a higher level. This butterfly is extremely shy and will disappear into the undergrowth when approached. The IUCN lists it as Endangered.

6. Ceylon Treebrown
Scientific Name – lethe daretis
Family – Nymphalidae
The wingspan of the Treebrown is about 50-60 mm. There seems to be significant differences between the male and the female. The male is a medium-sized, mostly dark brown butterfly having a series of dark sub-marginal spots on the hind wing. The underside is lighter with more vivid markings. It can be distinguished from all other similar looking species by the eye-spots on the underside of the hind wing. There are six eye-spots which are similar in size, shape and color pattern. The eye-spots are smaller of the male and the yellow band is absent. The female is larger and less brighter than the male. The undersides are similar in both sexes. The upper side of the female has a yellow band across the center of the forewing and a well-defined set of large eye-spots on the hind wing. It has a series of white streaks that form a diagonal line from the post discal area of the fore wing and a series of large spots faintly outlined in white on the hind wing.

It is sighted between elevations of 5,000 and 8,000 feet, but is confined to areas where bamboo grows because its host plant consists of the Poaceae family. It may often be seen settled on the ground by the side of forest paths. Though it usually flies away when disturbed, it does not venture too far away and resettles in the undergrowth where its camouflage makes it difficult to spot. It is listed as Endangered by the IUCN.

7. Ceylon Forester
Scientific Name – lethe dynsate
Family – Nymphalidae
Males are dark brown with the upper surface of the wings being unmarked except for faint dark eyespots on the sub marginal areas and tornal areas of the hind wings. Underside is heavily shaded and the sub marginal area of the wings carry a series of eye spots which are framed in speckled purple and helps to distinguish the butterfly from the treebrowns. Females are paler than the male and their underside is similar to the upper side except they are diffused. They can be found between 800 and 1200 feet where bamboo trees are found. Foresters have a swift flight and stay at a considerable height, but they also settle occasionally on the ground. It is quite rare and is listed as Endangered by the IUCN.

8. Blue Oak Leaf
Scientific Name – kallima philarcus
Family – Nymphalidae
Its large size and the unique blue color are easily distinguishable when compared with other Kallima species. It is leaf shaped, with the upper side colored in several hues of blue, brown and white. It has dried up leaf-like patterns on the underside which is completely contrasted with the upper side. It can adapt its colours to the changing seasons, the dry season form being somewhat larger and paler. It is not rare but local, from the sea level to about 2500 feet. It points its head down on a twig, with its tail in the contact with twig or branch to deliberately give the impression of a withered leaf hanging in a perfectly natural manner. It is a strong flier but settles often, while wings wide open towards the sun. They maintain a slow flapping of wings while basking. When it is been attacked by predators, it seeks refuge against a tree looking exactly like a withered leaf. At times it folds its wings and drifts down imitating the falling of a dead leaf. It’s also known to be fond of rotting fruits. It is listed as Vulnerable by the IUCN.

9. Jewel Four-ring
Scientific Name – ypthima singala
Family – Nymphalidae
The wing span of this butterfly is about 30-45 mm. There is one large eye-spot on the forewing and a series of smaller ones on the hind wing. Males and females look quite different on the upper side. This is a much more local butterfly than the White Four-ring and is confined to the hill tracts of the eastern part of the island, with some local populations near Kandy in the central hills. Hence it is less common. It is essentially restricted to grasslands in Uva district between the elevations of 500 to 5000 feet. It is a butterfly of the dry grasslands and is rarely seen outside this habitat. Its host plant consists of grasses belonging to bamboo family. This is a lively little butterfly that flies all day long among the short grass and herbs in its habitat in large groups. Its flight is weak and can be considered as a short skip or a bounce closer to the ground. It moves forward in a zigzag manner with a few crisp wing beats, often settling at regular intervals to rest nectar. If disturbed, it goes immediately to ground, trying to hide in low shrubs or thick grass within security but it does not remain very long. It is one of the first butterflies to come out in the morning, even in damp conditions and has a tendency to bask in the early morning with its wings partly open. It is listed as Endangered by the IUCN.

10. Ceylon Palmfly
Scientific Name – elymnias singhala
Family – Nymphalidae
Its wingspan is quite large and is about 60-80 mm. Its wings are dark brown and its patterns are more refined than the Common Palmfly. The edges of its wings are rugged with a faint white streak. It is rather shy and usually inhabits dark dense forests. It often flies as a couple and individual female can be seen hovering host plants. It has a fondness for over-ripe fruits. It is rare and can be found near Kandy and other similar elevations. It is listed as Endangered by the IUCN.

11. Ceylon Hedge Blue
Scientific Name – udara lanka
Family – Lycaenidae
It is a small family with a wingspan of about 25-30 mm. The upper side of the male consists of a uniform dark purplish-blue with a faint brownish tinge. The underside is shining silvery white with faintly marked in spots and lines. The female is lighter in shade. It is found in the up country and can be sighted in elevations between 3000 and 6000 feet and commonest between the months of February and October. It is most frequently encountered in forest foot paths and clearings and is also found in gardens of bungalows of tea plantations, though never far from hilly jungle.It likes to bask in the sun. It flies weakly about low bushes and shrubs and keeps away from tree tops. The males often settle on damp patches, sometimes in considerable numbers. The females may be seen at flowers. The IUCN lists it as Endangered.

12. Ceylon Cerulean
Scientific Name – jamides coruscans
Family – Lycaenidae
Like other butterflies of the Blues Family it is also small with a wingspan of 25-30 mm. It is bluish brown with white markings and a prominent dark spot on the underside of the wing. Also on the underside are acute ‘v’ markings on the outer marginal bands. It has a particular liking towards wild flowers for nectar. It is found up to 500m of the low country in southern parts of Sri Lanka. This is a forest dwelling species which flies at lower levels of the forest. When encountered, it is usually in the company of others of its kind. It is listed as Endangered by the IUCN.

13. Milky Cerulean
Scientific Name – jamides lacteata
Family – Lycaenidae
It is slightly larger than other Blues Family butterflies with a wingspan of about 32-35 mm. The upper side consists of a pale, shiny, purplish blue. The tail is black tipped with white. The underside is a pale grayish brown. The female is quite similar to the male.  It is found up to 500 m of the mid country and can be found throughout the country. It is extremely active, fluttering around plants for a long time before it settles. It is also jittery and will take flight when senses any disturbance. Confined mostly to forests and well wooded areas it usually flies near the ground and can rarely be seen. It is normally found in rabbles. It is listed as Near Threatened by the IUCN.

14. Woodhouse's Four Lineblue
Scientific  Name – nacaduba ollyeti
Family – Lycaenidae
It has a wingspan of about 30-32 mm. It has a particular tint of purple blue or deep purple on the upper sides. It can be distinguished by its similar species from their more brownish upper surface and the particular metallic gloss.  The female can be distinguished because its upper sides are more blue than purple. They also have a habit of sipping mud. These butterflies are very rare and can only be found in forested areas in the mid country. The IUCN has recorded its status as Data Deficient (which is done when proper studies and research have not been done with regards to the particular species).

15. Pale Ceylon Six Lineblue
Scientific Name – nacaduba sinhala
Family – Lycaenidae
It has a wingspan of about 18-28 mm. It is smaller in size than its similar species. Its colour patterns consist of particular silvery purple tint. It can be distinguished from its similar species from the three large whitish spots. The top of its front wings are round and are also transparent.  The female can be distinguished with its blue colour shade and tint and also because its front wings are shade of silvery white with dark bands.  It’s more common than the other species of Lineblues. These butterflies are mostly found in forested areas in the wet and intermediate zones. They are migratory and are also known to sip mud. The IUCN has recorded its status as Data Deficient.

16. Ceylon Indigo Royal
Scientific Name – tajuria arida
Family – Lycaenidae
It has a wingspan of about 24-26 mm. It is a silvery white butterfly with black spots. The underside is particular with a prominent black line. The female is similar to the male. The males of have reduced forelegs, lacking in claws. The antennae are banded with white. They are sun-lovers and enjoy basking. They tend to fly in a flitting, irregular manner staying close to the ground. It is found in the low country wet zone especially in the Haldumulla area. It appears in the new 500 rupee note. It is listed as Critically Threatened by the IUCN.

17. Ormiston’s Oakblue
Scientific Name – arhopala ormistoni
Family – Lycaenidae
It has a wingspan of about 24-26 mm. The colour patterns of this butterfly are made up of shades of brown and so it is able to camouflage itself well.  The female is entirely brown on the upper surface. It is extremely rare and can be found in the low country wet zone. The IUCN has recorded its status as Data Deficient.

18. Green's Silverline
Scientific Name – spindasis greeni
Family – Lycaenidae
They are small butterflies usually with a wingspan of 20-30mm. The butterflies are easily recognized by the silvery markings on the underside and the two hind wing tails. They are very distinct because of their colorful patterns. It has an extremely rapid flight. It is very rare in Sri Lanka and the IUCN has recorded its status as Data Deficient (which is done when proper studies and research have not been done with regards to the particular species).

19. Clouded Silverline
Scientific Name – spindasis nubilus
Family – Lycaenidae
It has a wingspan of about 24-26 mm. It has a dull indigo blue upper surface and is distinguishable from the other species by the glowing brick red color on the underside of the wing. The bands are not so dark and are separated by the black outlines and heavy silver lining. On its upper side, it has a brilliant shot blue at its hind wing. The female is similar to the male with the exception of the shot blue at its hind wing. It is considered as an extremely uncommon butterfly found in the low country dry zone up to 100m particularly in the North. It has an extremely rapid flight but settles often, upon which it can be approached easily. It is listed as Endangered by the IUCN.

20. Lesser Albatross
Scientific Name - appias galene
Family – Pieridae
It is a medium sized butterfly with a wingspan of about 50-60 mm. It is a variable species with distinct wet and dry season forms.  The upper side of it is cream, with a dark band that extends along the top of the forewings right up to the mid area. The hind wing is entirely yellow. The female differs from the male as its upper surface has broad dark bands that cover most of the upper area of the forewing and outer margins of the hind wing. It is one of the most common butterflies of the intermediate and dry zones of the island. It inhabits dry evergreen forests and scrub jungle. It is not found in the hills except during migration.

Usually they are very active, swarming and has a medium paced flight. They are sometimes seen resting within the forest shade during peak hours for foraging. It spends a great deal of time in the canopy of the trees searching for nectar and visits wild flowers readily but does not find ornamentals attractive. In late evenings it roosts in large numbers under the canopy of trees, settled on the upper surface of leaves with their forewings drawn into the hind wings. Both male and female butterflies are seen mud-sipping during the day time and sometimes form large swarms in dried up streambeds with a trickle of flowing water. It is listed as Endangered by the IUCN.

21. One Spot Grass Yellow
Scientific Name – eurema andersonii
Family – Pieridae
Its wingspan is about 35-40 mm. It is a bright yellow butterfly. There are a few markings on the underside. It differs from the other Grass Yellows by curved forewings, which gives it a rounder appearance. There is also a prominent and uneven, narrow black margin on the border of its wings. On the upper side of the hind wing there is a single small brownish spot. This species is the least variable species of Eureme in the country. It is an extremely rare butterfly which only lives in the wet zone of the island up to elevations of about 3500 feet and is mainly confined to wet evergreen forests.

It is somewhat gregarious and flies more weakly and hovers close to the ground. It inhabits forest edges and sunlit areas inside the forests and rarely ventures out into wide open spaces. Like other species in its family it also loves to sip mud. It is a species that breeds in forests or close to them, and has only been sighted at certain times of the year from April periodically to September. It is listed as Endangered by the IUCN.

22. Black Flat
Scientific Name – celaenorrhinus spilothyrus
Family – Hesperidae 
It has a wingspan of about 25-35 mm. It is a blackish brown butterfly with tiny white spots on its forewing. The females are similar to the males but have bigger white spots as well as small yellow spots on their forewings. The Black Flats belongs to the Skipper family and are so-called because they tend to skip from plant to plant. Although they are daytime fliers they are not true butterflies. The most common visible difference between a Skipper and a true butterfly is that they have hooks at the end of their antennae. Compared to other butterflies, Skippers have relatively smaller, elongated wings for their size. Unlike other butterflies they tend to rest for long periods of time with their wings opened flat (hence the name Flats). However, when they do fly it is with a lot of speed, especially in the smaller species.

All over the island from sea level to 3000 feet elevation, rarer or absent towards the North. Butterfly seems to prefer wet zone. This is a forest lover but visits open areas and home gardens where nectar plants grow. They are also frequently visible in riparian forest and open scrublands at forest edges. It is listed as Endangered by the IUCN.

23. Decorated Ace
Scientific Name – halpe decorata
Family – Hesperiidae

It has a wingspan on about 25-35 mm. It is a dirty yellow butterfly with a dark pattern at the edge of its forewings and another dark pattern in the middle of its wings. Like the other species in the Skipper family it too tends to skip from plant to plant. Like a moth the Decorated Ace also has a body which is quite disproportionate to its wings when compared to the average butterfly. Its body is also dirty yellow. This butterfly belongs to the sub genus Thoressa or the ace butterflies together with four other species. They are called ace butterflies because their shape tends to take a distinct triangular shape. It is extremely uncommon and is considered as Endangered by the IUCN.