Camouflage refers to coloration, patterns or behaviors that help an animal blend into its surroundings to avoid detection. There are several methods of camouflage used by insects, including color matching, disruptive coloration, mimicry and disguising color changes. Camouflage provides insects with important survival advantages by allowing them to avoid predators as prey or to ambush prey undetected as predators. It has evolved through natural selection over long periods of time and selection of camouflage traits continues today.
2. Camouflage refers to the use of a combination of materials, illumination or
coloration that makes an insect blend in with its environment, or makes it
harder to spot.
The natural world is full of amazing examples of camouflage, with the strategies
employed diverse and sometimes extraordinary. These include using markings
to match the colour and pattern of the background, as do various moths, and to
break up the appearance or shape of the body. Predators and prey alike use
camouflage to avoid detection.
Camouflage has long been used as a classical example of natural selection.
Perhaps for this reason, until recently, camouflage was subject to little rigorous
experimentation – its function and value seemed obvious.
Introduction
3. Camouflage has been a topic of interest and research in zoology for well over a
century. According to Charles Darwin's 1859 theory of natural selection, camouflage
evolved by providing individual animals with a reproductive advantage, enabling them
to leave more offspring.
The artist Abbott Handerson Thayer formulated what is sometimes called Thayer's
Law, the principle of countershading. However, he overstated in the 1909 book
‘Conaling- Coloration’ arguing that "All patterns and colours whatsoever of all animals
that ever preyed or are preyed on are under certain normal circumstances obliterate".
The English Zoologist Edward Bagnall Poulton studied insect coloration, especially
camouflage. His experiments showed that swallow-tailed moth pupae were
camouflaged to match the backgrounds.
History of Camouflage in Insects
4. Early evolution and ecology of camouflage in insects:
Taxa within diverse lineages select and transport exogenous materials for the purposes
of camouflage.
This adaptive behaviour in green lacewing larvae that nestle the trash among setigerous
cuticular processes, known as trash-carrying, rendering them nearly undetectable to
predators and prey, as well as forming a defensive shield.
A green lacewing larva in Early Cretaceous amber from Spain with specialized
cuticular processes forming a dorsal basket that carry a dense trash packet.
This discovery provides direct evidence of an early acquisition of a sophisticated
behavioural suite in stasis for over 110 million years and an ancient plant–insect
interaction.
Evolution of Camouflage in Insects
5. Evolution in Colour: Peppered Moths
The most famous example of mismatched colours first came to light in the 1950s. Coal
smoke had darkened England’s trees, so that light pepper moths, once blended nicely
against bark, now stood out against the smudgy background. A dark form of peppered
moths, once rare, became common. Birds quickly attacked the mismatched ones, as
had been predicted.
Evolution of Camouflage in Insects
Fig: White form of peppered moth. Fig: Black form of peppered moth.
6. To prey at ease: Predators camouflage themselves to
blend into its environment in order to stalk up their
prey. This is very common incidence of camouflaging.
Disguise from the predators: Animals that use
disguising camouflage can change their entire
appearance. This makes them more elite than insects
that can only change colour as they also have the
ability to change shape and texture.
Camouflage, also called cryptic coloration, is a defence or tactic that organisms use to
disguise their appearance, usually to blend in with their surroundings. There is several
importance of camouflage in insects for their survival at ease.
Importance Of Camouflage in Insects
Fig: A praying mantid matches the
texture and colour of the bark of a tree.
Fig: Katydid has the ability to look identical to its
habitat even in changing seasons.
7. More threatening look: Insect disguises its self as
a much larger or powerful animal in order to survive.
Protection of body: Insects camouflage to protect their
body both physically & immunologically.
Signalling to others: Camouflage is also used in
signalling for warning, mate choice and rival presence.
Physiological balance: Insects maintain
thermoregulation, UV- resistance, drought-resistance
through camouflage.
Importance Of Camouflage in Insects
Fig: The hawk moth caterpillar takes on the
shape of a snake when trying to act more
threatening that its venerable self to scare
predators.
8. Cellular basis: The basis of colour change has been studied for a considerable time, and
the varied mechanisms involved, primarily with regard to endocrine and cellular control.
Colour change can involve a range of mechanisms, and these can be quite different
between vertebrates and invertebrates.
Metabolic and physiological costs and constraints: Colour change is often assumed
to involve physiological costs and energetic expenditure. In cephalopods, controlling
large numbers of chromatophore cells rapidly and in synchrony continuously over time
probably carries a cost that impacts on the individual's energy budget.
Role of visual pathways: Most work on how visual information drives change in
appearance for camouflage has been undertaken in cephalopods. Such work has shown
that cephalopods change their patterns in response to the size, contrast and presence of
visual edges and discrete objects, among other factors.
Role of diet: While visual feedback for colour change is undoubtedly important in
many species, a role of diet also exists in some groups, and likely often interacts with
vision. For example, diet is known to influence coloration in some spiders.
Mechanisms of Camouflage in Insects
9. Concealing Colouration or Colour Matching: Colour matching is one of the most
basic ways insects camouflage themselves. Here insects hide against a background of
the same colour in order to protect themselves from predators and also for hunting their
prey. Some insects' colours and patterns resemble a particular natural background. In
each case the animal's coloration matches the hues of its habitat.
Methods of Camouflage in Insects
Fig: This butterfly matches the orange flowers
it gathers nectar from.
Fig: It can be easy to miss the grasshopper
since it’s the same colour as the blades of
grass nearby!
10. Disruptive Colouration: Many insects use more than one colour to help them blend in
with their surroundings. Spots, stripes, and asymmetrical shapes on their bodies can help
break up the outline of the insects and to escape from their predators. Disruptive patterns
use strongly contrasting, non-repeating markings such as spots or stripes to break up the
outlines of an insect.
Methods of Camouflage in Insects
Fig: This butterfly matches the bark of the
tree with the uneven stripes.
Fig: This little creature will be missed easily if
not noticed carefully.
11. Disguise or Active Camouflage: Some animals have the ability to change their colours
and patterns to help them blend in with their surroundings. The change in their appearance
or colour which gets the blend with their surroundings by their colour, texture and shape.
Some insects can quickly change their appearance, others change with the season.
Methods of Camouflage in Insects
Fig: The common walkingsticks are showing
the next level disguise.
Fig: This hopper disguises like the dry leaf of
the branches of a tree.
12. Mimicry or Mimesis: Mimesis is when an object appears to be something that it’s not.
It is coloration in a harmless animal that is similar to another animal that is dangerous,
bad tasting or poisonous. Prey insects sometimes mimic leaves, twigs, and other objects
that predators wouldn’t be interested in.
Methods of Camouflage in Insects
Fig: The oak leaf butterfly closely resembles a
dead leaf to disguise itself from hungry birds.
Fig: The katydid is another type of insect that
closely resembles a leaf.
Fig: The cloudless sulphur might be difficult to
spot in the fall since it mimics the colour and
pattern of yellow leaves.
13. Batesian mimicry: Henry Bates first proposed this theory on mimicry in 1861. In Batesian
mimicry in insects, an edible insect looks similar to an aposematic, inedible insect. The
inedible insect is called the model, and the lookalike species is called the mimic.
Example: Jumping spider, Myrmarachne which look striking similar to one of its predators
the weaver ant, Oecophylla Smaragdina.
Methods of Camouflage in Insects
Fig: Jumping spider is actually mimicking them.
Here, two ants flank a jumping spider.
Harmless: Papiliopolytes
Harmful: Pachlioptaaristolochiae
14. Müllerian Mimicry: In 1878, German naturalist Fritz Müller (1821-1897) offered a
different example of insects using mimicry. He observed communities of similarly
coloured insects and all of them were unpalatable to predators. Müller theorized that all
of these insects gained protection by displaying the same warning colours. If a predator
eat one insect with certain coloration and find it inedible, it would learn to avoid
catching any insects with similar coloration.
Methods of Camouflage in Insects
Bombus lucorum Bombus hypnorum Bombus terrestris Bombus hortorum
Fig: Many familiar bumblebees are Müllerian mimics, with effective stings and similar warning coloration.
15. Self-decoration: . Insects actively seek to hide by decorating themselves with materials
such as twigs, sand, or pieces of shell from their environment, to break up their outlines,
to conceal the features of their bodies, and to match their backgrounds.
Example: A caddisfly larva builds a decorated case and lives inside it. Predatory masked
bug nymph uses its hind legs and a 'tarsal fan' to decorate its body with sand or dust.
Methods of Camouflage in Insects
Fig: Masked hunter bugs camouflage
themselves by covering their bodies with
grains of sand.
Fig: The larvae of many caddisfly species make
hard cases out of whatever material they find
in the environment.
16. Motion Camouflage: Motion camouflage is achieved by moving so as to stay on a
straight line between the target and a fixed point in the landscape; the pursuer thus
appears not to move, but only to loom larger in the target's field of vision.
Example: Hoverflies and dragonflies use motion camouflage for mating and the
defending territories.
Methods of Camouflage in Insects
Fig: Male Syritta pipiens hoverflies use motion
camouflage to approach females.
Fig: Male Australian Emperor dragonflies use
motion camouflage to approach rivals.
17. Eliminating Shadow: Insects having flattened bodies, with the sides thinning to an
edge; the animals habitually press their bodies to the ground; and their sides are fringed
with white hairs which effectively hide and disrupt any remaining areas of shadow.
Methods of Camouflage in Insects
Fig: A caterpillar's fringe of bristles conceals its shadow.
18. Advantages Disadvantages
Insects with better camouflage are
more likely to survive.
Insects that survive will reproduce
and pass their colouring on their
offspring.
It allows the mimic to move about
and avoid predation without
having to stay still, as is often the
case in camouflage.
It can also be used as an aggressive
rather than defensive strategy.
Mimicry that involves pheromones
and aposematic coloration or other
warning signals can be costly to the
organism (Blount et al. 2008).
Furthermore, if the model species goes
extinct, migrates, becomes less toxic,
or evolves to look different than the
mimic, then the mimic could find itself
in a highly unfavourable situation.
Advantages & Disadvantages
19. From the long discussion we can reach to a conclusion that camouflage is
very special ability to insects. Whether in self-protection or in preying others
camouflage helps insects very much.
This feature of insects made them mysterious a well as interesting to us. It
has made a vast diversity among insect world.
Through several evolutions insects have achieved really interesting
camouflages for the survival, advantageous life, physical needs etc. And
they have become the researchable beauties to us.
Conclusion
20. 1. Evolution in Color: From Peppered Moths to Walking Sticks – National Geographic
2. Camouflage – Wikipedia
3. Benefits of insect colours: a review from social insect studies- Oluwatobi Badejo, Oksana Skaldina, Aleksei Gilev & Jouni Sorvari
4. The Importance of Camouflage – Prezi.com
5. Stevens M, Merilaita S. 2011. Animal camouflage: from mechanisms to function. Cambridge, UK: Cambridge University Press.
6. Camouflage – Definition, Camouflage Animals, Examples – BYJU’S
7. 32 Examples of Camouflage in Nature – Project Learning Tree
8. Exploring disguise and mimicry camouflage with youth - Michigan State University
9. Why do animals have different color patterns? - Michigan State University
10. Insect Camouflage - www.conservationindia.org
11. 11 Amazing Examples of Insect Camouflage – Treehugger
12. Balogh, A.C.V., G. Gamberale-Stille & O. Leimar. 2008. Learning and the mimicry spectrum: from quasi-Bates to super-Muller. Animal Behaviour
13. Blount, J.D., M.P. Speed & G.D. Ruxton. 2008. Warning displays may function as honest signals of toxicity. Proceedings of the Royal Society B
14. Cook, L. M., R. L. H. Dennis, and M. Dockery. 2004. Fitness of insularia morphs of the peppered moth Biston betularia. Biological Journal of the
Linnean Society
15. Camouflage 101 – Cryptics - University of Wisconsin-Milwaukee
16. Hiding in plain sight: How city insects have mastered the art of camouflage – www.scroll.in
References