Archive for the ‘Spiny-bodied Spider’ Tag

OGRE-FACED SPIDER: STARING YOU DOWN   4 comments


Wildlife, nature, fauna and flora of Costa Rica.

The weather is beginning to change.  There are now more rainy days with brief intervals of sun, generally shining in the morning.  Most of the nights are wet, with the rain beginning in the early hours of the evening then continuing through till dawn.  The rain is not heavy but it is constant.  This will now be the pattern until mid-November.  The opportunities to get out and take photographs is going to become more and more limited as the days and weeks go by.

Ogre-faced Spider

Sometimes you just have to be lucky and find yourself in the right place at the right time.  Many years ago I had taken some photographs of a particular species of spider and since then had been hoping to see this species again to get a close up of one of its startling features, the eyes.  I have come across it several times over the years but, unfortunately, never when I was carrying the camera.  Last week my luck changed and I found one without actually looking for it and I did have my camera in hand.

The spider in question is an Ogre-faced Spider, (Deinopis sp), of the family: Deinopidae.  Once you see the spider in close up then the reason for the name will be revealed.  Those two large, forward-facing eyes give the appearance of a mythical ogre staring at you.

Rainforest animals. Rainforest Spiders. Ogre-faced spider. Deinopidae. Costa Rica.

Ogre-faced Spider, (Deinopis sp), easier to see at an angle

The Ogre-faced spiders are not typical orb-weavers, they belong to a group known as lace-web weavers and have evolved a different means of employing silk to catch prey.  There are only 57 species of Ogre-faced spiders but they are found throughout the tropics.  They have long legs and a long abdomen, (opisthosoma).  If they do move, it is slowly and deliberately.  The coloration matches the tree bark on which they are commonly found hanging in a head down position.  During the day they lie flat against the tree to avoid being seen.  But as the sun sets they move into position and set about constructing the ingenious part of its prey capturing trap which is held between the front two pairs of legs.

These four legs have a dry silk frame strung between them.  Attached to the frame is a net made from sticky elastic silk.  An unsuspecting prey item passing below the spider is in for a nasty surprise.  The spider, connected by a dragline drops and opens the front four legs which extend the net.  It is dropped onto of the victim and when the legs are drawn together again the net closed and ensnares the spiders next meal.  The web is shaken a few times to ensure the prey is completely enmeshed, all the while the spider is wrapping in more silk from the spinnerets and continually biting its prey to inject the venom.  The secured and now deceased prey is held in the palps while the spider feeds and at the same time constructs a new net ready for the next meal to arrive.

Spiders. Rainforests. Costa Rica. Ogre-faced Spider.

The long-legged, long-bodied Ogre-faced Spider

The feature I was interested in were the eyes.  At 1.4mm in diameter, these forward-facing eyes are the largest simple eyes possessed of any land invertebrate.  The eyes have an equivalent camera f/stop of 0.6 which enable them to see very well in dark conditions, the time when the spider hunts.  This, combined with retinal receptors capable of absorbing the smallest amount of ambient light, 2000 x more than other spiders, means they can hunt in, what to you and I, is total darkness.  You can’t see the spider but the spider can see you.  Also, this one was a male as can be seen from the enlarged pedipalps under the front of the head.  These are used during spider mating.

Rainforest animals. Rainforest Spiders. Spiders. Deinopis sp. Ogre-faced Spider. Costa Rica.

Now you can see those eyes and the features that give it the name; Ogre-faced Spider

Weirdness on the Web

It has been a spidery kind of week.  When I was out walking the trails I noticed a small web strung across the path with what I first thought was a small spider removing the papery veil of a Jacaranda seed that had landed there.  In the past I have seen various orb-weavers cutting the silk securing an unrequired piece of material that had land in the web, hold it out with their legs until free of the web and let it drop to the ground.  Not too far down the same trail I saw a similar thing so I decided to take a closer look.  The spider itself was very small and with the naked eye it looked strange, I had not seen this species before and could not quite make out the form.  Something just wasn’t right.

Rainforest animals. Rainforest Spiders. Micrathenidae. Micrathena gracilis. Costa Rica.

Spiny Micrathena hanging from web, viewed from behind

I took several photographs and looked on the camera screen.  The body of the spider was unlike any I had previously seen.  The abdomen, (opisthosoma), was drawn up dorsally and expanded laterally.  It was covered in a series of fleshy, thorn-like protuberances.  I was looking at a Spined Micrathena, (Micrathena gracilis).  During the course of the day I found 3 of these spiders, which is strange because I had never seen this species before.  Later, when back online and researching more information, I learned it is quite common and widespread.  Oh well, new for me and happy to have finally made its acquaintance.

Rainforest animals. Rainforest Spiders. Micrathenidae. Spiny Micrathena. Costa Rica.

Dorsal view of Spiny Micrathena Spider

Only a few meters down the trail from where I photographed the Spined Micrathena I found another web traversing the path at about 6 feet above the ground.  Sitting in the center was yet one more spider that I was unfamiliar with.  I knew it was one of the Spiny-bodied Spiders, of which I have found a variety of different species over the years.  Unlike Micrathena gracilis above, most Spiny-bodied Spiders are brightly colored and elongated with spines and thorns projecting from the body, sometimes giving them an arrow-shape.  I knew this was a Micrathena, the body was long with black centered red spots on a yellow background and with only two more fleshy spines pointing backwards from the abdomen.  Extensive searching failed to produce a name for this species.  So two new spiders in one day and within several feet of each other.

Rainforest animals. Rainforest Spiders. Spiny-bodied Spider. Micrathenidae. Costa Rica.

Strange Spiny-bodied Spider, (Micrathena sp), awaiting identification

Finally I noticed a small web strung not too far above my head in the open garden area.  In the center of the web was a small brightly-colored but very distinctively spider.  The abdomen was vivid lemon yellow with a series of black spots drawn out sideways into an oval shape bearing ferocious looking thorns around the edge.  This was another Spiny-bodied Spider, (Gasteracantha cancriformis).

Rainforest Spiders. Rainforest animals. Gasteracanthinae. Spiny-bodied Spider. Costa Rica.

Spiny-bodied Spider, (Gasteracantha cancriformis)

They are a very common species but are so small that you generally don’t notice them until you walk into the web.  To avoid this situation the silken strands securing the web are flocked with fluffy pieces of silk to make it more obvious to larger creatures.  They come in various color, yellow, white and red being the commonest.  They are very widespread, being found from southern U.S. to northern Brazil and everywhere in-between including the Caribbean Islands.

It is a very short-lived spider; the females die after producing an egg cocoon and the males die a short time after mating.  In certain locations it is another spider that has a reputation it does not deserve.  Some of the native populations regard it as being very venomous.  It is quite harmless.

Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica

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TARANTULAS AND THE DANCE OF DEATH   2 comments


Wildlife, nature, fauna and flora of Costa Rica.

The weather on Cabo Matapalo continues to favor the visitor.  Over the past week the days have been dry and sunny, there has been little rain at all.  The rain that has fallen has been at night after everyone has returned to the comfort of their cabins.  There was one afternoon when an electric storm developed over the tip the tip of the peninsula.  Thunder echoed loudly throughout the forest, the rumbles seemingly shaking the ground beneath your feet, whilst simultaneously lightning sizzled and cracked overhead illuminating the surrounding area with blinding flashes of light.  The rain poured vertically down from the heavens and within no time the paths had turned into running rivers.  The whole event lasted little more than an hour and ended as abruptly as it began.  The thunder rolled off into the distance, a herald of the deluge that was about to be visited upon the neighboring areas.

There would appear to be no letup in the enthusiasm of the breeding amphibians.  Each night the number of calling males remains constant.  The vegetation around the pond is covered in the eggs of many species.  It is strange that this year should have seen a surge in the population of Small-headed Frogs, (Dendropsophus microcephala), which previously have been present in small numbers but this year have exploded to the point where they are the most vocal of nightly serenaders.

This has also been an exceptional year for the White-nosed Coatis, (Nasua narica).  They are normally to be found around the gardens and throughout the forest and therefore are easily encountered.  One of the first animals people see upon arrival are the coatis with their striped tails, slightly curved at the tip, stuck directly up in the air.  The males are solitary and tend to bolder in their approach to people.  The females, which band together in large groups with the young, until recently were more shy and retiring, they would run if you got too close.  At least that is how it used to be.  Now they are not so inclined to move out of the way.  They will look at you with furtive glances, on their toes ready to run if you make a fast movement towards them, but if you move slowly they will continue about their business just maintaining a wary watch.  It could well be that after so many years of being watched in this fashion that they have become familiarized with their human observers and no longer perceive them as an immediate threat.

A Touch Too Much

The sun is setting, its last red glowing rays now only picking out the top of the trees, creating the illusion that the canopy is on fire.  You grab your flashlight knowing that the fire will rapidly fade into the burnt-out embers of dark red and ultimately dampened into darkness.  With this darkness an awakening occurs, creatures of the night are beginning to emerge.  Before all becomes blackness, the silhouettes of bats can be seen against the sky, leaving their daytime roosts to feed on all manner of food.  Here the bats feast on a sumptuous banquet, each of the 80 species on the Osa Peninsula having its own preferred diet.  There are insectivorous bats, nectar-feeding bats, fruit-eating bats, carnivorous bats, fish-eating bats and yes, even blood-feeding bats, the vampires.

In the background, the plaintive whistle of a Great Tinamou can be heard, its three ascending sad notes announce that the day has ended and the night has begun.  As if on a collective cue, the insects start to call.  The soft but rhythmic pulsating sound of katydids and crickets fills the still nighttime air.  The shrill call of parrots and macaws fill the darkening sky as they pass overhead returning to their nightly roosts.  Now, adding to the white noise of the insect symphony comes the call of the amphibians.  They have been tucked away, hidden during the day from the harsh and drying effects of the sun’s rays, not good for creatures that breath through a delicate moist skin.  But as the air cools it becomes damper, perfect for males to begin to emerge, set up a territorial platform and start to call.  If he is lucky, a female will be attracted to the tone of his voice, oblivious to our ears, but sweet music to hers conveying the potential genetic quality that she would wish for her offspring.  Finally the deep roars from the male Howler Monkeys as they settle down for the evening are telling you it is time to venture out.

You step out into the darkness, flashlight up by your eye scanning the area immediately in front of you looking for eyeshine.  You are familiar with the various colors and the distinctive way the eyes of different animals reflect back at you.  There is something.  Fiery orange eyes on the ground, it blinks so it is not a snake, it hops up and down and then it calls and flies off.  That you could identify quite easily as one of the nighthawks, a Common Paureque, (Nyctidromus albicollis). Now over there in a tree, more bright orange eyes staring down at you.  You walk over to see what might be observing you.  Before you get close enough to make out its form it calls, a Spectacled owl.  It opens its wings, leans into the night and silently slips away, gliding like a feathered phantom into the blackness.  So not a bad start to the evening.

There are diamonds sparkling everywhere, on the ground, in the vegetation, all colors, red, orange silver, green and blue.  Anything with a diamond sparkle eyeshine you know is a spider and there are hundreds, no thousands of spiders, in whichever direction you look.  Most of them are little more than the size of a pinhead.

Your free hand is resting on the low branch of a tree sticking out horizontally from the trunk at about hip level.  You are glaring into the tangled vegetation in front of you looking for some of the amphibian choristers that you hear calling when you feel something lightly brush against your hand.  You don’t retract you grasp quickly but rather gingerly lift your hand away and turn the flashlight in the direction of where it was resting.  There you see the creature that had inadvertently made contact with you before withdrawing.  Its body is large and hairy, it has eight stout and hirsute legs.  Your pulse races and a bead of sweat rolls down by your eye from your brow.  It could be due to the heat of the night but it is probably because you are looking at a tarantula.

Tarantula. Rainforest Spider. Mygalomorphae. Therasophidae.

Unidentified Tarantula species in the Costa Rican rainforest

Tarantulas And The Dance Of Death

Now mistakenly putting your hand on a tarantula in the dark would increase the heart rate of most people but like so many other maligned creatures, the poor tarantula has a reputation it does not deserve and nor can it live up to.   Despite their size and grotesquely fearsome appearance, tarantulas are shy and mostly harmless creatures.  They are however venomous and a large, hairy, many-legged venomous arthropod is generally going to suffer bad press amongst their misinformed human observers.

Costa Rican Tarantulas. Mygalomorphae. Theraphosidae. Tarantula.

A rather shy Tarantula does not want its picture taken

Venom is a complex cocktail and quite often it can be very different and peculiar to different types of spiders depending upon their preferred dietary prey species.  Once a spider catches its prey, the victim must be rendered immobile very rapidly, especially if it is not caught in a web and then swaddled in restraining silk.  Most venoms therefore contain fast-acting metabolic toxins that kill or paralyze the prey rapidly.  In this respect, tarantula venom is very weak and does not have much effect on humans but it will kill dogs.  Spiders do not have mouthparts capable of mastication so essentially they have to drink soup, that soup being the digested internal organs of their prey.  The venom contains proteolytic enzymes that break down and liquidize the tissues so that the spider can suck up the rich protein meal and finish the process of digestion within its own alimentary canal.

So why does the tarantula have a reputation of being so dangerous.  The story has its origins in a city located in mediaeval southern Italy called Taranto.  Here lives a wolf spider, (Lycosa tarantula), one bite from which would drive the victim into a state of frenzied madness more commonly known as tarantism.  The unfortunate sufferer was prone to dizziness, vomiting and a heightened sensitivity that compelled them to lose all inhibitions and dance in a wild state of abandon trying to release themselves from the effects of the venom.

Due to these effects, it has been suggested that the spider responsible was Latrodectus tresdecimguttatus, closely related to Black Widow of the U.S.A and the Red-back Spider of Australia.  It may well have been that in a mediaeval Italy gripped by religious fervor that most cases of tarantism were little more than the result of a pious mass hysteria and not a spider induced dance of death.  However the story travelled with European settlers to tropical America and from thereon  the poor tarantula was saddled with the name and its resulting reputation from its smaller, deadlier European cousins.

Tarantula. Mygalomorphae. Theraphosidae.

Tarantula sp – look closely and you can see the fang-tipped chelicerae

The tarantula in these photographs was found last week on the grounds here.  It was not very co-operative and shied away from having its picture taken.  When I tried to get a close-up on the fangs, it pulled all of its legs up against the body.  I did manage to get low down and in front to get an image that if you look closely reveals the two fangs, which in the case of tarantulas are parallel to each other and face forwards.

Small But Deadly

Talking of smaller spiders, there is one species I see commonly around the buildings of the area that could be quite easy to miss.  It prefers dark corners where two walls meet at right-angles.  It is dark ruddy-brown and spends the day with its legs tucked up under the body.  The web is little more than a few silken strands strung between the two wall faces.  What draws your attention is not the spider itself but the size of prey it captures and consumes.  I quite regularly see everything from large kaydids, beetles and moths dangling helplessly from the sticky diaphanous cords as a tiny spider cautiously approaches to deliver the coup de grace.

Although I do not profess to being an expert with regards to spiders, (nor with anything in fact), I think these tiny assassins belong to the family: Theridiidae, which includes the notorious Black Widow, (Lacrodectus mactans).  The venom of the spiders in this family is highly neurotoxic which would explain why prey so much larger than the spider rapidly succumb to its bite.  I don’t know anyone who has been bitten by one of these individuals I commonly find lurking in places like bathrooms and have no great desire to try and find out for myself.

Tangle-web Spider. Araneidae. Araneae. Theridiidae.

Tangle-web Spider female guarding egg cocoon

The individual in the photograph sat guarding a grey sac for many days.  This is the egg cocoon.  She will mate with a male then lay her eggs which she will wrap in silk in order to protect them against the environment and parasites.  When these ones hatched I would see them swarming all over a prey item along with the mother.  I never saw her wrap a victim in silk, they just remained suspended in death pose from the strands upon which they had initially and unfortunately become caught.

Choking On A Poisoned Thorn

One more spider that I found last week in the gardens is so distinctive that it can be identified immediately, at least to genus level.  This is one of the Spiny-bodied Spiders, (Micrathena sp).  They are small but tend to be dressed in bright and contrasting colors so you should not have too much trouble finding them if you are diligent in your searching.  They are orb-weavers but the web, just as its maker, is relatively small.  Spiny-bodied Spiders are more commonly found in the open areas rather that within the depths of the forest.  Their webs can be found strung between the twigs and branches of bushes and small trees.

Once you have located one of the Spiny-bodied Spiders you will quickly appreciate why is bears that name.  The rear of the abdomen is drawn out into two long vicious-looking thorns at the base of which are two shorter spines.  The dorsal surface of the abdomen has a pair of upward pointing spines while the ventral surface has one downward pointing spike.  This whole appearance is not an appetizing prospect for a potential predator.  The coloration of bright vivid primary colors against darker background colors actually make the spider stand out in contrast to its surroundings.  If it is visibly obvious then it is patently not trying to hide.  It is using warning, (aposomatic), coloration to advertise its presence to a predator.

Spiny-bodied Spider. Araneidae. Araneae. Micrathena sp. Rainforest Spiders

The spines covering its body are a clue to the naming of the Spiny-bodied Spider, (Micrathena sp)

Should a naïve predator such as a bird or lizard ignore that warning signal and try to feed on the spider, those thorns and spines will lodge it in the unfortunate creature’s mouth from which it is very difficult to displace.  The spider meanwhile produces a noxious secretion that tastes foul and the hapless predator, rather than relishing a tasty meal, is now stuck with spiny vile dietary experience.  One the spider is dislodged, the predator will never, ever go near anything sporting aposomatic colors again.

Shadowy Parasites – Not Green And Not Seen

While walking the trails I found a weird little plant that could easily be mistaken for a fungal fruiting body.  It grows from the ground with a short fleshy stalk holding up the flowering head.  The overall color is the same as the ground, a ruddy-brown, there is no green to be seen.  In appearance it looks like no other flowering plant.  It contains no chlorophyll because it is an obligative parasite.  It taps into the roots of trees from where it extracts all its nutritional requirements.  This is Helosis cayennensis of the family: Balanophoraceae.  They can be found in northern and southern hemisphere tropics.

Parasitic plants. Balanophoraceae. Rainforest plants. Helosis cayennensis

Strange acorn-shaped inflorescence of Helosis cayennensis

The main body of the plant is an amorphous underground tuber attached to the root it is parasitizing.  The flower head produces both male and female flowers both of which are small in size.  Quite often they can be found in large clusters, especially this time of year, the wet season, growing out from the base of the tree they are sucking the life from.

Balanophoraceae. Helosis cayennensis. Parasitic rainforest plants

No green to be seen – the parasitic Helosis cayennensis

Philip Davison Is a Biologist, Writer and Photographer Based in Costa Rica

Flying a Dangerous Flag   6 comments


Philip Davison. Costa Rica. Blog. Nature Diaries

Thursday 28th January 2016

Stay Behind the Barrier

Black and yellow is the most visible color combination that exists.  It follows that any creature sporting patterns in this visually obvious blend might not be trying to conceal itself.  Bees, wasps and hornets are generally striped in yellow and black.  Many poisonous spiders, butterflies and caterpillars are decked out in the same fashion.  If they are not trying to hide then they are making themselves obvious, for whatever reason they are telling you to stay away.  This strikingly acute combination of color is known as aposematic coloration or warning coloration.  Humans use it too in the form of black and yellow striped tape to keep people from getting too close to a dangerous situation.

In the area of Matapalo these colors can be frequently seen and encountered throughout the forest.  Flying along the forest rides and around the nectar giving bush Lantana camara in gardens are the brightly colored Heliconiids or longwinged butterflies.  One of the most common of these is Heliconius sapho, its yellow banded velvet black wings beating slowly interspersed between periods of short glides as it makes its way down the trails.  This aesthetic beauty is telling potential predators one thing – “STAY AWAY”.

The Postman Butterfly. Heliconius sapho.

The butterfly is unpalatable and what makes it unpalatable is the fact that it is packed with cyanide.  Having a toxic defense against predation serves no purpose if the predator does not know about it.  Eating one of these butterflies would result in the death of the butterfly and the creature eating it.  The predators learn through experience.  Once a predator, whether it be a bird or a lizard, catching and trying to feed on one of these butterflies will experience a foul taste caused by the cyanide.  It spits it out and it does not take too long before the black and yellow coloration is associated with something so wholly unpleasant that anything dressed in the same colors will be avoided with a passion.

Leaf it Alone

It is not just adult Lepidoptera that use toxic defenses; many caterpillars are prone to do the same. Frangipani, (Plumeria rubra), despite being thought of as a Hawaiian plant whose flowers are used to make the leis to put around the necks of tourists, is actually native to Central America.  It is the national plant of Nicaragua.

Frangipani continually flowers throughout twelve months of the year.  As the sun sets the pale white blossoms give off a heavenly scented sweet perfume which drifts into the night, the aroma of which attracts night-flying hawk moths.  The moths are attracted with the promise of a nectar rich feed.  But nectar is energy expensive for the plant to produce so the plant cheats the moth; it reneges on the promise and produces no nectar at all.  The duped hawk moth searches in vain but to no avail, the long proboscis probes into one flower after another and becomes covered in pollen.  Flying from flower to flower it transfers the pollen and pollinates the plant.  The moth having thus been enticed subsequently receives no reward for its labors.

There are moths that unwittingly have their revenge, the Frangipani Hawk Moth (Pseudosphinx tetrio).  The eggs of this moth are laid on the undersides of the Frangipani leaves.  Upon hatching the caterpillars are very small, only 10 – 15 mm.  They won’t stay that way for long.  After consuming their own egg shell they set about consuming the leaves with gusto.  The caterpillar is a committed eating machine; it turns plant tissue into animal tissue at an incredible speed.  They can almost be seen to grow day by day.

The last part of the leaf to be eaten is the stalk.  If damaged the stalk leaks a stiff white liquid rich in alkaloids.  The alkaloids are very toxic and would normally deter anything from consuming the leaf.  The Frangipani Hawk Moth caterpillars store the alkaloids in their bodies making them in turn highly toxic.  Once more that information needs to be relayed to any potential predator to save both parties from harm.  The vividly black and yellow hoops with a flash of bright red head, tail and legs should serve the purpose very well.  It appears to do so as these caterpillars feed in full view both day and night on the very naked limbs of the Frangipani.

Frangipani Hawkmoth. Pseudosphinx tetrio

Within little more than a week the plant will be denuded of leaves and the caterpillars will have increased to a very stout 60 – 70 mm.  Should more plant tissue be needed to complete the larval stage before pupation then the caterpillars set about consuming the rubbery branches of the tree.  One night, as if by magic, all the caterpillars will have disappeared, retiring to some secluded nook or cranny to pupate before emerging in the future as a relatively drab moth which will mate and start the process over again.  Although the Frangipani may look a little forlorn in its leaf denuded state, it really doesn’t take long for it to produce fresh growth, in fact quite often on parts of the plant as the caterpillars are still feeding.

Beware a Colorful Meal

Spiders might not be that easy to find but once you start to look they are everywhere.  In common with many other forms of life, the species richness and diversity of spiders is huge.  More obvious than most are the orb weaving spiders, the webs of some species traversing large expanses between trees.  However there are many smaller spiders with consequently smaller webs.  One of the more distinctive of these is the Arrow-bodied or Spiny-bodied Spider, (Micrathena sexspinosa).  Either name is appropriate and speaks for itself.

The body of the spider has an array of spines and thorns which in itself should be enough to discourage any potential predator.  But sometimes physical defenses can be overcome.  The spider has invested in a second insurance policy – a foul-tasting chemical defense.  As with the above butterflies and caterpillars there is no point having that means by which to avoid predation if the predator is oblivious to its existence.  So once again aposematic coloration comes into play, the spider is dressed in a black and yellow checkered pattern.

Spiny-bodied Spider. Micrathena sexspinosa.

Any naive bird or lizard that ignores the warning signs and tries to eat the spider will end up with the spider jammed in its bill or mouth by way of the spines and thorns.  All the while the spider issues from its skin a nasty tasting secretion that the unfortunate predator has to endure while trying to remove the spider from its bill or mouth.  Once the cause of the vile experience has been eliminated then the bird or lizard will probably never attempt to eat anything black and yellow again.

Tiny Timid Tigers

For the last example of black and yellow aposematic coloration we turn to the hymenoptera, more specifically the ants.  Ants like spiders may not at first be as obvious as mammals, birds and butterflies but take the time to look at little more closely and they most certainly are there.  Leaf-cutter Ants are hard to miss, their long winding ribbons of green cut leaf fragments running like verdant rivers across the forest floor.  Army Ants likewise when in a foraging frenzy move in fronts upto sixty feet across appearing as an almost large black plastic sheet being pulled across the forest floor, its intent being the slaughter and butchering of all small forms of life unfortunate enough to not be able to escape from its path.  Noisy excited attendant birds and the hum of parasitic flies usually herald its approach.

But rather than these mass movements there are many other ants that occur in smaller numbers.  Seen walking down tree trunks, along branches and roots in small lines like kids playing follow the leader are distinctive black ants with golden bands, the Tiger Ants, (Camponotus seriseivestris).

Tiger Ants are closely related to the Carpenter Ants and share the same life history as general foragers taking nectar, seeds and fruit from plants.  They attend aphids and certain Lycaenid caterpillars for honeydew as well as taking small creatures either dead or alive.  They live in colonies in hollows within dead or living trees but in much smaller numbers than Leaf-cutter or Army Ant colonies.

Tiger Ant. Camponotus sericeiventris

The name Tiger Ant conjures up visions a seriously ferocious adversary capable of doing limitless damage to any unsuspecting tourist that accidently puts his hand upon them.  In actual fact they are harmless, most certainly to humans, the name referring to the coloration rather than their nature.  They do however have a means of defense if disturbed.  The aggravated ant will turn its abdomen between its legs so the rear end is facing forwards and then it will shoot a jet of formic acid towards its aggressor.  Many ants indulging in the same defensive strategy will generally deter the cause of its ire to retreat to a safe distance.

Philip Davison is a biologist, writer and photographer based in Costa Rica.

 

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