Posted tagged ‘Camouflage’

Why you (may) dislike Arthropods and I don’t!

4 January 2011

I’m absolutely sure that most of you who see the image above will cringe, shudder or grimace.  These fearsome  (to some) creatures are Arthropods and they are by far the most numerous set of creatures on Earth. Insects, scorpions, crabs, centipedes and shrimp and many others comprise this group. All these have jointed legs – hence their name.

I am talking about a form of “racism” in our human culture – our attitudes to species other than our own.


The wonderful diversity of Arthropods (Image:User xvasquez on Wikimedia Commons, Public domain)

Mammals? Like us, they are warm (blooded), furry, and some arey cute. Birds? Interesting creatures that fly  (I wish I could do that) and listen to how sweetly this one trills. Fish? Only good for a meal! Reptiles? Definitely on the other side of midnight along with arthropods.

The origin of our dissonance with the environment is Mankind’s inherently false belief that we are separate from Nature. Since we are the only species that has been able to think about the future and the environment to meet our future needs, we consider ourselves above and beyond it. Our scientific and technological progress, instead of increasing our knowledge and giving us an enlightened view of things, has made us prideful of our ability to range across our realm from the Moon to the depths of the Ocean, to extract our materials from living and non-living things and to fashion with them things which help us create strange and wondrous things, to increase our population way beyond the natural capacity of the Earth and to mine the natural world for even more.

Even though from time to time, Nature sends us reminders that we are finite and an infinitesimal part, but nevertheless a part in the grand scheme of things, in our pride, like the Gods, we see ourselves apart.

Yet, a barf of ash from a once dormant volcano in Iceland has halted all the air traffic over most parts of Europe. And there is nothing our technology can do to prevent this.

Refusing to believe the evidence of our senses, we lumber on ignorantly, confident in our belief that we, as a species, are superior. That Nature is there at our bid and call for the express purpose of our convenience. That we have conquered Nature. That all its creatures exist at our pleasure. That Man is the Measure of all things.

This attitude, surely an express highway to self-destruction, is the reason that we like some creatures and hate or ignore all the rest.

Why do we dislike arthropods so much? The answer to this must surely lie in childhood.

As an infant, we may have had an experience in which an insect or other creature walked on us, tasted horrible or flew into our face. Our caring elders would have hurried us away from them or warned us against them. Should we have been unfortunate enough to have been stung or bitten by one, it would imprint on our tender psyche forever. As time passes, the looks and the activities of these creatures reinforce the negative images about them. We feel that since they are small, they could fly onto us even perhaps into one of our orifices. Their legs, antenna and spikes on the body remind us of thorns.  Their numerous legs make us imagine how it will feel crawling on our hands!  In the absence of anything positive feedback about creepy-crawlies, we develop an abhorrence of ‘bugs’.

Our belief is now firm and irrational. The “mythos” has overtaken our “logos”. Blind belief instilled as fears as a child supercede rational understanding gained as an adult. It will take a conscious act for us to detach the negative feelings that these creatures engender in us. Since we are Man with a developed brain and a conscious mind, we can do so.

As I did many years ago.

In the words of Dr Steve Kellert (read more here) :

Dr. James Hillman, in a classic essay, “Why we hate Bugs?,” provides some psychological insight regarding why these differences between humans and invertebrate scale and behavior might result in feelings of alienation and aversion. Reviewing a long history of prejudicial attitudes and antagonistic behavior of humans toward arthropods, Hillman remarks, “what we call the progress of Western civilization from the ant’s eye level is but the forward stride of the great exterminator.” Hillman suggests four reasons for human psychological aversion and antipathy toward invertebrates, mainly insects and spiders, found among most people in Western society.

First, he emphasizes the “multiplicity” of the invertebrate world, which he suggests threatens our fondly cherished human notions of individuality and independence. He suggests the idea of a bee hive that can include 50,000 individuals, or a large ant colony of half million ants, or an acre of soil with 65 million insects, or beetle species numbering more than one million, represents a fundamental challenge to our sense of personal integrity and individual oneness. He remarks: “Imagining insects numerically threatens the individualized fantasy of a unique and unitary human being. Their very numbers indicate insignificance of us as individuals.”

A second basis for anxiety and aversion, Hillman refers to as the “monstrosity” of most invertebrates from a human perspective. In this regard, he notes the tendency of most people to associate invertebrates, especially insects and spiders, with metaphors of madness and mindlessness. The human presumption, as noted, is to assume invertebrates as incapable of feelings and rationale reflection, and many common terms of insanity employ insect names, while images of madness often involve visions of insects and other arthropods. As Hillman suggests: “Bug-eyed, spidery, worm, roach, blood sucker, louse, going buggy, locked-up in the bughouse – these are all terms of contempt supposedly characterizing inhuman traits… To become an insect is to become a mindless creature without the warm blood of feeling.” A third explanation Hillman offers for dislike of invertebrates originates in their radical “autonomy” from human will and control. A particularly disturbing aspect of their independence or indifference to human hegemony is the willingness to invade human space in unexpected and uninvited fashions.

Finally, Hillman suggests a disturbing element about invertebrates for most humans stems from the quality of “mystery” surrounding them. As noted, invertebrates represent radically different behavioral and morphological strategies in the struggle for survival which for most humans provokes considerable uncertainty, confusion, and a sense of “otherworldliness.” This sense of mystery can be a basis of curiosity, interest, and even wonder, although the more typical reaction is one of disdain and fear of the unknown. For most humans, invertebrates are largely unfathomable and alien.

Hillman suggests conservation of wildlife, especially invertebrates, will necessitate a far greater understanding of why we react with hostile and negative feelings toward various creatures, particularly insects and spiders. To find our commonality with the animal world in its widest diversity, “we must start (with animals) not in their splendor – the horned stag, the yellow lion and the great bear, or even old faithful `spot’ – but with those we fear the worse – the bugs.”

The above paragraph gives many reasons on a psychological level why people regard arthropods as abhorrent. In the same way, people fear snakes and are blind to the amazing abilities that the snakes have evolved despite having no limbs of any kind.

Arthropods are such wonderful creatures in so many ways, I find it hard to select which facts to tell you about them.

Let me start with camouflage.

Insects (and other arthropods) are nutritious food. They contain valuable protein and reserves of fat in some cases. All kinds of animals eat them – birds, mammals, reptiles, fish, amphibians. Even man eats them – this is called entomophagy.

As an aside, no matter how strict a vegetarian you are, you eat insects every day. Here‘s why?

In order to avoid being eaten insects adopt a variety of strategies, one of which is camouflage. Camouflage is a method of crypsis—avoidance of observation—that allows an otherwise visible organism or object to remain indiscernible from the surrounding environment through deception. Examples include a tiger‘s stripes and the battledress of a modern soldier. The theory of camouflage covers the various strategies which are used to achieve this effect. (Courtesy:Wikipedia)

A Leaf Insect from Wyanaad, India. Here, the camouflage is used defensively, to escape being eaten. (Image:Sandilya Theuerkauf on Wikimedia Commons, CC-BY-SA-2.5)

 

A stick insect - shades of Tolkien's ents! (Image:Fir0002 on Wikimedia Commons, CC-BY-SA-3.0)

A challenge - find the pink soft coral crab hiding in the soft coral of the East Timor Sea. (Image:User Nick Hobgood on Wikimedia Commons, CC-BY-SA-3.0.)

Did not succeed? Okay try again after seeing another photo of this amazing crab – Pink Soft Coral Crab, Hoplophrys oatesii, placed after this one of camouflage used not to hide from predators but to become one! An evolutionary arms race!

 

Camouflage for predation - A perfectly camouflaged jumping spider captures a solitary wasp. (Image:Muhammed Mahdi Karim on Wikimedia Commons, GFDL 1.2)

 

The coral crab now visible on Pink Coral. Image:User Nick Hobgood on Wikimedia Commons, CC-BY-SA-3.0.)

Camouflage for predation - A crab spider can change its colour depending on the flower it chooses to live in to catch its prey, in this case a wasp. (Image: Olaf Leillinger on Wikimedia Commons, CC-BY-SA-2.0-DE)

The two forms of the Peppered Moth. Earlier the melanistic (dark) form was uncommon while the peppered form was predominant. The increasing soot on trees in England due to the industrial revolution changed the evolutionary dynamics and today the melanistic form predominates as the peppered form has been selected out due to high visibility on blackened bark of trees.

The Peppered Moth Biston betularia (Linnaeus, 1758) is a text book case for evolution. Changes in environment reduced the viability of one morph and increased that of the other. The insect evolved accordingly to have a predominantly larger population of darker morphs.  This graphic of a related Geometer Moth shows how effective camouflage can become a hindrance once the environment changes. Drag the mouse over the background to see it disappear and show just the moth. The moth is perfectly camouflaged on the tree bark but if the background changes, as in the case when you dragged the mouse, the moth becomes prominent and a target instead.

Want to see more?

Insects have many facets similar to the trades of humans.

If you are an underwater diver, you would be interested in the Diving bell spider.

The diving bell spider or water spider, Argyroneta aquatica, is a spider which lives entirely under water, even though it could survive on land. (Image:Norbert Schuller Baupi on Wikimedia Commons, CC-BY-SA-3.0)

If you keep cows or sheep, the ant also belongs to your trade guild . Many species of ants “herd” aphids for honeydew. The ants in turn keep predators away and will move the aphids around to better feeding locations. Upon migrating to a new area, many colonies will take new aphids with them, to ensure that they have a supply of honeydew in the new area.

 

An ant guards its aphids. (Image:ViaMoi on Flickr/Wikimedia Commons, CC-BY-SA-2.0)

 

Ants feeding on the honeydew of the aphids. Notethe dewdrop exuding from the rear of the aphid. (User:jmalik on Wikipedia, Creative Commons 3.0)

If you are a soldier like me, you will be interested in the army ant. The name army ant (or legionary ant or “Marabunta“) is applied to over 200 ant species, in different lineages, due to their aggressive predatory foraging groups, known as “raids”, in which huge numbers of ants forage simultaneously over a certain area, attacking prey en masse.

Another shared feature is that, unlike most ant species, army ants do not construct permanent nests, an army ant colony moves almost incessantly over the time it exists. All species are members of the true ant family, Formicidae, but there are several groups that have independently evolved the same basic behavioral and ecological syndrome. This syndrome is often referred to as “legionary behavior”, and is an example of convergent evolution. (courtesy:Wikipedia)

 

Some safari ant soldiers on the Chogoria of Mount Kenya make a tunnel to provide a safe route for the workers. (Image:Mehmet Karatay on Wikimedia Commons, CC-BY-SA 3.0)

The amazing number of examples of insects and other arthropods which can illustrate any phenomenon or theme that you want is mind-boggling. Like the scope for thematic collectors in a world of 530,000 or so postage stamps, the many hundreds of thousands of arthropods are more than enough to satisfy the curiousity of any person.

Perhaps the following links will help you to become interested in arthropods and nature :

For children:

For the more enthusiastic:

As a closing quote, let us see another view of the “Age of Man” :

Don’t accept the chauvinistic tradition that labels our era the age of mammals. This is the age of arthropods. They outnumber us by any criterion – by species, by individuals, by prospects for evolutionary continuation.

Stephen Jay Gould, 1988

It is time to shed our inhibitions and accept the notion that these too are God’s creatures and deserve to live on Earth as much you do.

NOTICE : This post has already been published as a Guest Post on Gingerchai.com over here . Special thanks to Lakshmi Rajan for giving a platform for my contrarian views.

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The beetle which changed colours

9 January 2009

One comes across the wonders of natures almost accidentally. In June 2006, on the thirteenth to be precise, my son Aashay and I had driven along the Pokaran – Jaisalmer road to look at Tawny Eagles, who are easily found every few hundred metres perched on the wires or poles. On the way back, we stopped to say hello to a local acquaintance. He stood at his present place of labour, a dolomite mine the concession of which he had taken. The mine, near Chacha village, some 20 odd kms from Pokaran, consisted of an area approx 200 yards in diameter in the middle of which there was a large pit some ten yards across and about ten feet deep. Inside, the pit had tunnels leading from the sides which my friend claimed were quite long and winding and undermined almost all the area of the mine. On the surface, occasional holes with large piles of white dolomite stones around the entrances hinted at the warren below.

The dolomite quarry where we found the beetle.

The dolomite quarry where we found the beetle.

As fathers are prone to do, conversations turn to worldly matters or ‘shop’ so Aashay went wandering around the mine. A fatherly warning followed Aashay that he should stick to the beaten tracks only.

Fifteen minutes later, I walked upto Aashay to fetch him. It was 8.30 and time that we made our way back home for breakfast. Aashay was bent over, peering at something on the ground. It was a beetle scurrying on the ground.

”Pappa” he said, ”there’s something strange about this beetle!”

We followed it as it meandered amongst through the broken stone and sand. It was beautiful, almost completely white with a few black markings. A white beetle being a novelty, I was keen to get close and take a photograph but the beetle did not cooperate. Realising it was being pursued, the beetle changed tack and now hurried along on a twisting path towards some Aak bushes (Calotropis spp). A picture on the ground was difficult to get so Aashay chased it trying to scoop up the dodging creature. This he did, only to lose it a few seconds later. We did however succeed in taking a few snaps.

What was truly amazing was that the beetle, which was almost completely white when Aashay had spotted it, gradually turned darker and darker until finally it was almost completely black with only a very thin white edging.

The creature finally reached sanctuary – a cluster of Aak roots with twisted branches, dried leaves and small crevices into which it disappeared. The Rajasthani locals who worked the mines told us that the beetle turned black with fright but would recover to its original pattern after 15 minutes or so.

Immediately after we encountered the beetle it began turning black.

Immediately after we encountered the beetle it began turning black.

Scooped up in Aashay's hands for taking a good snap, it has almost turned completely black.

Scooped up in Aashay's hands for taking a good snap, it has almost turned completely black.

Later I put up the images on Wikipedia WikiProject Arthrpods talk page, hoping for an identification. Doug Dynega, an entomologist and museum curator in the States, responded whith what appears to be the key to the mystery:

”It’s a Tenebrionid, but I can’t be certain of the subfamily. From what I can see in the photos, the white “markings” are, like in many desert Tenebs, not markings, but fine cuticular wax deposits. I’d never heard of the beetle being able to change the amount of wax on it, so I have a better explanation, based on what one can observe; the wax layer is hygroscopic (absorbs moisture), and when it does so, it loses its reflectivity. Holding the beetle in your hand will greatly increase the humidity in the airspace near the beetle. This makes some sense as a desert adaptation; when humidity is low, the beetle reflects more sunlight, and when humidity is high, it reflects less. I’ve just never heard of the phenomenon, and can’t confirm it myself. What you need to do is catch one, kill it, and experiment. If it’s that sensitive, even breathing on it should have a noticeable effect. If it can be confirmed, it might even be something to publish, assuming no one has documented it before.”

Sadly, we left the area soon after and could not go back to explore this mystery any further. A pretty little puzzle waiting for someone to unravel it!

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Notes.

1. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, with no Front-Cover Texts, and with no Back-Cover Texts. A copy of the license is included in the section entitled “GNU Free Documentation License“.

2.  Comment by Doug Dynega published under GFDL copyright from Wikipedia at the Talk page of WikiProject Arthropods on Wikipediaaccessed on 08 Jan 2009: