The art of deception

Beautiful and graceful, varied and enchanting, small but approachable, butterflies lead you to the sunny side of life.  And everyone deserves a little sunshine.  ~Jeffrey Glassberg

I am at loss of words to describe the beauty of butterflies. The intricate wing patterns with amazing color combinations will definitely be an inspiration to artists and designers. How often have you wished to be a butterfly flying from flower to flower leading a carefree life? But it is not easy to be a butterfly as it has its own challenges, like protecting itself from its predators. To overcome this challenge some butterflies  have mastered the art of deception.

Crimson rose – Unpalatable butterfly

As a protection strategy some poisonous butterflies like the Common Rose (Pachliopta aristolochiae) and the Crimson Rose (Pachliopta hector) are brightly colored. The bright coloration warns the predators that these butterflies are unpalatable.  These butterflies have a slow flight as they are not attacked by predators.

Now how do other butterflies which are non poisonous protect themselves?

• Rapid flight with  iridescent wings  to dodge predators
• Camouflage in the surroundings they are found
• Eyespots and tails are found in some  butterflies and which divert the attention of predators from the more vital head region.
• Mimicking  the wing patterns of toxic butterflies, a phenomenon known as Batesian mimicry

Crimson Rose (poisonous ) avoided by predators

Common Mormon(non poisonous ) mimicking the wing pattern of the Crimson rose

“Some female Common Mormons look similar to the male, but others mimic the color patterns of two unrelated species the Common Rose (Pachliopta aristolochiae) and the Crimson Rose (Pachliopta hector). It is interesting that males in this species are always non-mimetic and females may be mimetic. It could be due to the reason that females carry eggs and therefore their abdomens are much heavier compared to males, making them slower in flight and therefore easier prey for birds. This special vulnerability to predation makes females more dependent on mimicry for their survival compared to males. Females have a particular advantage if they mimic locally common toxic Rose butterflies.”-  Krushnamegh Kunte.

Common Rose (poisonous )

Common mormon (non poisonous) mimicking the  Crimson Rose

A single gene regulates the complex wing patterns, colors and structures required for mimicry in swallowtail butterflies, according to a study led by scientists from the National Center for Biological Sciences, India, and the University of Chicago, USA. The work published in Nature  redefines the mimicry supergene in this butterfly: for over half a century biologists believed it to be a cluster of tightly-linked genes, but the current study shows that it is a single gene. “Our study throws new light on the intriguing genetic basis of wing patterning in a butterfly that mimics others,” said Dr. Krushnamegh Kunte, Reader (Assistant Professor) and Ramanujan Fellow at NCBS and the lead author of the paper.

“The co-option of this well-known sexual differentiation gene in controlling polymorphic mimicry is indeed an unexpected and exciting discovery. doublesex is a highly conserved and well-characterized gene in insects. Its function in sexual differentiation is understood a fair bit, but previously it had not been implicated in wing patterning,” said Dr. Kunte.

For Dr. Kunte who grew up in Pune watching the Common Mormon butterfly, it was a ‘natural progression’ to study the underlying mechanisms of mimicry, he said. “I grew up watching this splendid butterfly and the toxic species that it mimics in my neighborhood. Later, during my development as an evolutionary biologist, this childhood fascination of swallowtail butterflies turned into an academic research program to find out how selection facilitates and shapes the diversification of animal lifeforms. Swallowtail butterflies is what I have known in so many ways for so long, therefore trying to understand the ecological and genetic controls of mimicry and  polymorphism in this species was a natural progression.”

Source article

Kunte, K., Zhang, W., Tenger-Trolander, A., Palmer, D.H., Martin, A., Reed, R.D., Mullen, S.P., and Kronforst, M.R. 2014. doublesex is a mimicry supergene. Nature, Published online 5 March 2014. DOI:10.1038/nature13112

Some links on this finding can be found below

http://phenomena.nationalgeographic.com/2014/03/05/the-supergene-that-paints-a-liar/

http://news.uchicago.edu/article/2014/03/07/single-gene-called-doublesex-controls-wing-mimicry-butterflies

http://www.reuters.com/article/2014/03/05/us-science-butterfly-idUSBREA241U720140305

http://news.sciencemag.org/biology/2014/03/supergene-lifesaver-colorful-butterfly

Mimicking the Tiger

On one of our butterfly trails in Camp Gee Dee we found a group of  Dark blue tiger – Tirumala septentrionis  and the Double branded crow – Euploea sylvester   butterflies feeding on roots of plants . These butterflies belong to the   danaid family also known as the milkweed family , thrive on the juices of poisonous plants .

They feed on the toxic alkaloids found in certain plants.This action is supposedly to extract the chemical pyrrolizidine alkaloids from these plants to aid in their defense mechanisms and also to produce pheromones. When a hungry bird pecks on them, it triggers a fearful physiological reaction in the predator’s body. This result in predators learning this memorable aspect at first hand. Predators soon associate the patterns and habits of such butterfly species with unpalatability to avoid hunting them in future. A great deal of sexual selection happens based on this. Females select the most distasteful males to ensure a safety of the progeny.

Danaid eggfly Female mimicking the Plain tiger

Plain tiger – poisonous

The potential predators remember that the Danaids are unpalatable and avoid them . An interesting study by Dr Tom Eisner and his colleagues at Cornell University, U.S.A., working with the tiger moth . He observed that tiger moths are rejected by certain orb weaving spiders, which cut them from their webs rather than eat them. The Cornell researchers have shown that the moths are unpalatable to spiders and to birds because of the pyrrolizidine alkaloids the caterpillars gather from their food plants. The spiders will eat moths from caterpillars reared on an alkaloid-free diet, but find even their palatable items, such as mealworms, unacceptable as food when alkaloids have been added. Amazing to know how the predators have adapted .

The click of the Danaid eggfly female has bee downloaded from Wikimedia Commons

Few  Interesting links  on how a Single Gene Controls Mimicry Across Different Species

http://www.sciencedaily.com/releases/2011/07/110721142416.htm

http://www.sciencedaily.com/releases/2012/05/120516135502.htm

A link on how one butterfly species can gain its protective color pattern genes ready-made from a different species by interbreeding with it — a much faster process than having to evolve one’s color patterns from scratch

http://www.sciencedaily.com/releases/2012/05/120516140014.htm