Thursday, May 21, 2015
Friday, May 15, 2015
Camouflaging techniques of Nerium Moth Caterpilar (Army Green Moth , Oleander hawk-moth) Daphnis nerii
My observations related to Oleander hawk-moth
Oleander hawk-moth is a medium size moth found in Asian and African regions.
It flies very fast hovering flower to flower usually in the evening and in the dark after sunset. It feeds on nectar of various night time flowers.
It's caterpillars feed mainly on leaves of Oleander tree. The leaves of Oleander (Nerium oleander -කණේරු ) are highly toxic but these caterpillars are immune to it.
The newborn caterpillars are light blue in color. They feed on tender leaves and hurriedly go to eat the flowers at the top of the trees if they are available.
Oleander trees come in various types based on the color of the flower. It has white, pink and dark red or magenta varieties.
Oleander / කණේරු
When the caterpillar eat the flowers the color pigments of the flowers enter to its body without passing out in feces. The pigments are accumulated in the soft layers of its body. As it keep eating the flowers and grow in size it gets the color of the flower due to this accumulation of color pigments.
If the caterpillar is thriving in a tree with pink colored flowers it becomes pink. If it is living in a white flowered tree it becomes light green. When they eat dark magenta flowers the body color changed to reddish color.
I have personally observed this phenomenon in many seasons during my childhood times, 1970s, when I was living in Ratmalana, Sri Lanka.
If the same mother moth laid eggs in different colored trees same siblings get the colors of their host plant. Sometimes observers mistakenly count them as different types of the moth.
The tender leaves and flowers are always at the top of the Oleander tree and the caterpillars become easy prey to predators.
Due to this technique of camouflaging the predators cannot see them when they are at top of the trees.
When they complete the lava stage in trees they start descending to the ground or to the lower part of the tree to start the next stage of metamorphosis. As they reach this stage the color of all the caterpillars changed to dark brown.
The Caterpillar
The cocoon
Oleander hawk-moth is a medium size moth found in Asian and African regions.
It flies very fast hovering flower to flower usually in the evening and in the dark after sunset. It feeds on nectar of various night time flowers.
It's caterpillars feed mainly on leaves of Oleander tree. The leaves of Oleander (Nerium oleander -කණේරු ) are highly toxic but these caterpillars are immune to it.
They eat Tabernaemontana divativa (Nerium divaricatum) වතුසුද්ද leaves too.
Leaves and many other parts of of Oleander tree is poisonous to many animals as it produce cardiac glycocides such as oleandrin and oleandrigenin.The newborn caterpillars are light blue in color. They feed on tender leaves and hurriedly go to eat the flowers at the top of the trees if they are available.
Oleander trees come in various types based on the color of the flower. It has white, pink and dark red or magenta varieties.
Oleander / කණේරු When the caterpillar eat the flowers the color pigments of the flowers enter to its body without passing out in feces. The pigments are accumulated in the soft layers of its body. As it keep eating the flowers and grow in size it gets the color of the flower due to this accumulation of color pigments.
If the caterpillar is thriving in a tree with pink colored flowers it becomes pink. If it is living in a white flowered tree it becomes light green. When they eat dark magenta flowers the body color changed to reddish color.
I have personally observed this phenomenon in many seasons during my childhood times, 1970s, when I was living in Ratmalana, Sri Lanka.
If the same mother moth laid eggs in different colored trees same siblings get the colors of their host plant. Sometimes observers mistakenly count them as different types of the moth.
The tender leaves and flowers are always at the top of the Oleander tree and the caterpillars become easy prey to predators.
When they complete the lava stage in trees they start descending to the ground or to the lower part of the tree to start the next stage of metamorphosis. As they reach this stage the color of all the caterpillars changed to dark brown.
The Caterpillar The cocoon
Images courtesy of Viran Vas, Shantanu Kuveskar and Krishna Mohan
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