Insects and Spiders of Sri Lanka: What to Look For

Antlion Common

Myrmeleon sp.

Antlion larvae excavate funnel-shaped pits in fine dry soil and bury themselves at the bottom with only the jaws exposed. Prey that slides in is bombarded with flicked sand until it falls within reach, then seized and drained.

Where: Conical pits in dry sheltered sand and dust, under overhangs and building eaves. Best: Year round. The pits are everywhere once you notice them. The adult is a slender lacewing-like insect that most people never connect to the larva. Also on: Yala National Park, Sigiriya, Dambulla and the Cultural Triangle.

Blue Tiger Common

Tirumala limniace

Blue tigers are milkweed butterflies that sequester toxic alkaloids from their food plants, making them unpalatable and slow, confident fliers. Seasonal migrations move large numbers between breeding and dry-season roosting areas.

Where: Open forest, scrub and roadsides, sometimes in large aggregations. Best: February to April and October to December. Roosts communally in shaded gullies, sometimes hundreds together, which is worth stopping for if you find one. Also on: Sigiriya, Dambulla and the Cultural Triangle, Gal Oya National Park.

Common Emigrant Common

Catopsilia pomona

A medium sized, fast flying, lemon to greenish white butterfly, often with a small silver-ringed spot on the underside. Highly variable, and the same species turns up in several colour forms.

Where: Open country, scrub and roadsides countrywide, and in numbers on the move. Best: February to April for the migration. Samanala Kanda, Adam's Peak, means Butterfly Mountain, and this is the butterfly it is named for. Also on: Adam's Peak and Peak Wilderness, Sigiriya, Dambulla and the Cultural Triangle, Yala National Park, Jaffna and the Northern Peninsula, Mannar and the Gulf of Mannar.

Common Mormon Common

Papilio polytes

Common mormon males are plain black with a band of white spots, while females occur in multiple forms, some mimicking toxic rose swallowtails complete with red body markings. The mimicry is controlled by a single supergene.

Where: Gardens, citrus and scrub countrywide, including in towns. Best: Year round. Females come in several forms, some mimicking the poisonous roses and some not, which is one of the classic worked examples in evolutionary biology. Also on: Kandy, Colombo and the wetlands.

Common Picture Wing Common

Rhyothemis variegata

A small dragonfly whose wings are broadly patterned in amber-gold and black over most of their area, giving a fluttering, wavering flight quite unlike a normal dragonfly's.

Where: Over marsh, paddy and tank margins in the dry zone. Best: Year round, strongest after rain. Flutters like a butterfly. Most visitors do not realise they are looking at a dragonfly at all. Also on: Minneriya and Kaudulla National Parks, Bundala National Park, Colombo and the wetlands, Gal Oya National Park, Wasgamuwa National Park.

Common Rose Swallowtail Common

Pachliopta aristolochiae

A striking black butterfly with white hindwing patches, a ring of rose spots and a red body. Its leisurely flight warns predators of the toxins it carries from pipevines.

Where: Gardens, scrub and roadsides countrywide. Best: Year round. The commonest of the roses here and the model for a well known mimicry system: female common mormons imitate it closely enough to fool a bird. Also on: Yala National Park, Sigiriya, Dambulla and the Cultural Triangle.

Crimson Rose Common Near Threatened

Pachliopta hector

A black swallowtail with two bold rows of white bars across the forewing, a line of crimson crescents on the hindwing, and a bright crimson body.

Where: Dry zone scrub, garden edges, roadsides and park tracks countrywide. Best: Year round. Slow and low along tracks. One of the easiest butterflies on the island to watch properly. Also on: Yala National Park, Wilpattu National Park, Bundala National Park, Sigiriya, Dambulla and the Cultural Triangle, Kumana National Park, Wasgamuwa National Park.

Giant Honey Bee Common

Apis dorsata

The largest honey bee in the region, building a single huge exposed comb high on a branch, cliff or building. Colonies are defensive and can mount mass stinging attacks.

Where: Enormous single combs hanging from cliff faces, overhangs and tall forest trees. Best: Year round; colonies migrate seasonally. The species involved in the mass stinging incidents on the Sigiriya rock stairways. Also on: Sigiriya, Dambulla and the Cultural Triangle, Adam's Peak and Peak Wilderness, Knuckles Range.

Wandering Glider Common

Pantala flavescens

A slender golden-yellow to amber dragonfly with unusually broad hindwings, almost always seen in the air rather than perched.

Where: Hawking over paddy, open ground and tank margins, often in swarms. Best: With the first rains of either monsoon. Time it to the rain, not the month. A swarm can appear in a day and be gone in three. Also on: Minneriya and Kaudulla National Parks, Bundala National Park, Colombo and the wetlands, Jaffna and the Northern Peninsula, Mannar and the Gulf of Mannar, Tangalle and Kalametiya.

Weaver Ant Common

Oecophylla smaragdina

A highly social tree ant that builds nests by pulling leaves together and binding them with silk squeezed from its grubs. Colonies are aggressive and defend their trees fiercely.

Where: Leaf nests stitched into the canopy of garden and forest trees countrywide. Best: Year round. Builds its nest by pulling leaves together and gluing them with silk squeezed from its own larvae, which the workers use as living tubes of glue. Bites hard and sprays formic acid into the wound. Also on: Yala National Park, Kanneliya Forest Reserve.

Shining Gossamerwing Regular

Euphaea splendens

A stocky damselfly, black with pale thoracic markings; the male's hindwings are black with a metallic blue-green sheen on the upper surface, the forewings tinted brown.

Where: Perched on rocks and twigs over shaded, fast, rocky wet zone streams. Best: Year round, sunniest hours. Wait at a sunlit gap over a rocky stream and let the males come to you. Also on: Sinharaja Forest Reserve, Kitulgala and the Makandawa Rainforest, Kanneliya Forest Reserve.

Ceylon Tiger Occasional

Parantica taprobana

A medium sized butterfly with pale blue-white streaks and blotches on a dark brown ground, the pattern broken into long finger-like markings that run out from the body.

Where: Montane grassland, forest edge and hill roadsides above about 1,000 m. Best: Year round, sunniest hours. Altitude is the identification. Below the hill country you are looking at one of its commoner relatives. Also on: Horton Plains and Nuwara Eliya, Ella and the Uva Highlands, Knuckles Range, Adam's Peak and Peak Wilderness.

No free photograph of the Ceylon tiger exists. The image shows the glassy tiger, Parantica aglea, a close relative photographed in southern India.

Ceylon Tree Nymph Occasional

Idea iasonia

A very large butterfly with semi-translucent chalk white wings marked by a scatter of black spots and heavy black veins, and an unusually weak, floating flight.

Where: Canopy gaps and clearings in lowland wet zone forest. Best: Year round. Identifiable at thirty metres from the flight alone. Nothing else on the island moves like it. Also on: Sinharaja Forest Reserve, Kanneliya Forest Reserve, Kitulgala and the Makandawa Rainforest.

Giant Asian Mantis Occasional

Hierodula membranacea

A large praying mantis that sits motionless among leaves before seizing prey with spined forelegs. It can take insects, and occasionally small vertebrates.

Where: Shrubs, garden vegetation and at lights after dark. Best: Year round. Also on: Sinharaja Forest Reserve.

Giant Water Bug Occasional

Lethocerus indicus

Giant water bugs ambush prey in still water, seizing it with raptorial front legs and injecting digestive saliva through a stout beak. They fly strongly at night and are drawn to lights, which is when most people meet them.

Where: Still and slow fresh water: tanks, paddy, marsh and roadside ditches. Best: Year round, and at lights after rain. A genuinely formidable predator that takes fish, tadpoles and even small snakes. The bite is painful and among the most painful of any insect, so do not pick one up. Also on: Minneriya and Kaudulla National Parks, Bundala National Park.

Mango Longhorn Beetle Occasional

Batocera rufomaculata

Mango longhorns are large grey-brown beetles marked with pink-red spots, with antennae far exceeding the body length in males. Larvae bore for years through living hardwood, and adults chew bark and shoots.

Where: On mango, fig and other broadleaf trees, and at lights. Best: April to July, night. Also on: Kandy.

Oleander Hawkmoth Occasional

Daphnis nerii

Oleander hawkmoths feed on the wing, hovering at night-scented flowers and probing with a long proboscis without landing. The wings are marbled in olive, pink and cream in a pattern that reads as lichen when the moth is at rest.

Where: Gardens and scrub wherever oleander and periwinkle grow, at dusk and at lights. Best: Year round, at dusk. Hovers at flowers at dusk like a small hummingbird. The caterpillar is a startling green and blue thing with a false eyespot. Also on: Colombo and the wetlands, Tangalle and Kalametiya, Rekawa and Kosgoda.

Rhinoceros Beetle Occasional

Xylotrupes gideon

A large, shining brown beetle in which males carry a curved thoracic horn used to lever rivals off branches. It feeds on sap and fruit and can squeak when handled.

Where: At lights after dark, and on palms and rotting wood. Best: October to December and April to June, night. Males wrestle with the horn for access to females and can lift many times their own weight. Also on: Kitulgala and the Makandawa Rainforest.

Sri Lanka Birdwing Occasional

Troides darsius

A very large swallowtail with black forewings and broad golden yellow hindwings veined in black, the body marked crimson at the head and thorax. Females are larger and duller than males.

Where: Forest edge, gardens and flowering trees across the wet and intermediate zones. Best: Year round, strongest after the rains. Sri Lanka's national butterfly. The gliding flight is the giveaway from a distance. Also on: Sinharaja Forest Reserve, Kitulgala and the Makandawa Rainforest, Kandy, Kanneliya Forest Reserve.

Atlas Moth Rare

Attacus atlas

A colossal moth with russet, patterned wings and curved tips said to mimic a snake. The adult has no working mouth and lives only a few days to breed.

Where: Forest edge and lit buildings near forest across the wet zone. Best: October to December and April to June, at night. One of the largest moths in the world. Adults have no working mouthparts and do not feed at all, so they live about a week on what the caterpillar stored. Also on: Sinharaja Forest Reserve, Kitulgala and the Makandawa Rainforest.

Ceylon Rose Rare Critically Endangered

Pachliopta jophon

A large black swallowtail streaked with white on both wings and edged with crimson crescents along the hindwing margin, with crimson on the head and the sides of the body.

Where: Wet zone rainforest interior and its immediate edge, nowhere else. Best: Year round. Critically Endangered. If you think you have one outside wet zone forest, it is almost certainly a crimson rose. Also on: Sinharaja Forest Reserve, Kanneliya Forest Reserve.

Green's Gem Rare

Libellago greeni

A very small, stocky damselfly, the male marked in black and brilliant orange-yellow with pale legs, perching on rocks and twigs right at the water surface.

Where: Rocks and twigs at the surface of shaded, fast, rocky wet zone streams. Best: Year round, sunniest hours. Look at water level, not above it. Almost everyone scanning for damselflies looks a metre too high. Also on: Sinharaja Forest Reserve, Kitulgala and the Makandawa Rainforest, Kanneliya Forest Reserve.

Sri Lanka Blue Oakleaf Rare

Kallima philarchus

Upperside deep blue-black with a broad orange band across the forewing. Underside a mottled brown dead leaf, with a false midrib, false veins and false rot spots, and a short tail that mimics the leaf stalk.

Where: Forest floor, fallen fruit and sap runs in wet zone forest. Best: Year round. Watch where the blue flash lands, then look for the dead leaf that is facing the wrong way. Also on: Sinharaja Forest Reserve, Kitulgala and the Makandawa Rainforest, Kanneliya Forest Reserve.

No free photograph of the Sri Lanka blue oakleaf exists. The image shows the scarce blue oakleaf, Kallima knyvettii, a close relative photographed in southern India.

Sri Lanka Relict Ant Ultra rare Critically Endangered

Aneuretus simoni

A very small, pale yellowish ant with an unusually slender waist, nesting in rotting twigs and leaf litter on the rainforest floor. Nothing about it looks remarkable, which is rather the point.

Where: Rotting twigs and leaf litter on the floor of undisturbed wet zone forest. Best: Year round. You will not identify this in the field and that is not the point. It is the last species of an entire subfamily of ants and it is under the leaf litter you are standing on. Also on: Sinharaja Forest Reserve, Kanneliya Forest Reserve.

Golden Orb-weaver Common

Nephila pilipes

A large forest spider whose females hang in huge webs of shimmering golden silk, dwarfing the tiny males. The silk is remarkably tough and gleams in the sun.

Where: Huge golden webs slung across forest tracks and clearings countrywide. Best: Year round, largest females August to December. Known throughout Sri Lanka as the giant wood spider. The silk is strong enough that you feel the web before you see it. Also on: Sinharaja Forest Reserve, Kanneliya Forest Reserve, Yala National Park, Kitulgala and the Makandawa Rainforest, Kumana National Park, Gal Oya National Park.

Signature Spider Common

Argiope anasuja

A medium sized orb weaver with a silver and yellow banded abdomen, sitting head-down at the centre of its web with the legs paired into an X and a conspicuous zigzag of dense white silk below it.

Where: Webs slung in scrub, gardens and dry zone forest edge countrywide. Best: Year round. The zigzag in the web is the identification, and its purpose is still argued about. Also on: Yala National Park, Bundala National Park, Sigiriya, Dambulla and the Cultural Triangle, Udawalawe National Park, Kumana National Park, Wasgamuwa National Park.

Giant Forest Scorpion Occasional

Heterometrus swammerdami

A very large, glossy blue-black scorpion with heavy pincers, a comparatively slender tail and a sting that looks far more alarming than it is.

Where: Under logs and stones by day, out hunting on the ground after dark. Best: Year round, after dark. A UV torch finds them from several metres. It is the single most rewarding five pounds of kit for a night walk. Also on: Yala National Park, Wilpattu National Park, Sigiriya, Dambulla and the Cultural Triangle, Udawalawe National Park, Kumana National Park, Wasgamuwa National Park.

Fringed Ornamental Tarantula Rare

Poecilotheria ornata

A very large arboreal tarantula, greenish yellow to purplish on the carapace, with paired yellow spots along the leg segments and a white mark on the hind femur.

Where: Cavities in mature trees in lowland wet zone forest, at the web entrance after dark. Best: Year round, after dark. Look for the funnel web at a tree hollow rather than for the spider. Never put a hand or a light-stick into the hole. Also on: Sinharaja Forest Reserve, Kanneliya Forest Reserve, Kitulgala and the Makandawa Rainforest.

Ivory Ornamental Tarantula Rare

Poecilotheria subfusca

A large arboreal tarantula with a dark abdomen marked by three linked dark spots, a brown carapace with a pale starburst margin and creamy chelicerae.

Where: Cavities, bark fissures and old woodpecker holes in mature hill forest trees. Best: Year round, after dark. Needs old trees with existing holes, so it is found in remnant forest and old estate shade trees rather than young regrowth. Also on: Kandy, Knuckles Range, Ella and the Uva Highlands.

Sri Lankan Ornamental Tarantula Rare

Poecilotheria fasciata

A large arboreal tarantula patterned in grey, cream and black in a herringbone arrangement, with bold yellow and black banding on the undersides of the front legs that shows when it rears.

Where: Cavities and loose bark on mature trees in the drier zones, and occasionally old buildings. Best: Year round, after dark. The one Poecilotheria most likely to be found near people, because it tolerates drier and more disturbed forest than the others. Also on: Sigiriya, Dambulla and the Cultural Triangle, Wilpattu National Park, Kandy, Wasgamuwa National Park.