Evening after the Photography workshop on 6th Dec 2009 I was tired from all the presentation and talk which happened at the workshop. Having taken bulk of the topics and over 8 sessions my throat was aching. We had 32 very nice enthusiastic youngsters who attended the workshop.The interaction was great and we all learned a lot about photography from each other. When I returned to my in-laws place at Bondel, Mangalore, I was eagerly greeted by my daughter who showed this plump green caterpillar which she sighted on the flowering bush in their garden. She had seen the similar caterpillar earlier at her school backyard and wanted to know the identification. There were 3 caterpillars on that Crape jasmine (Tabernaemontana divaricata) plant. They were caterpillars of the of the oleander hawk-moth.
The Oleander hawk-moth, Daphnis nerii (Linnaeus, 1758), one of the most widely distributed species of sphingid in the world, is known to occur in Africa, southern Europe, Arabia, Afghanistan, Pakistan, India, Sri Lanka, Myanmar, Nepal, Thailand, Yunnan (south China), Hong Kong, Taiwan, the Philippines, Sumatra, Peninsular Malaysia, and North Borneo, and has been introduced to southern Japan, Hawaii, and Guam. Its vernacular name refers to the oleander, Nerium oleander (family Apocynaceae), on which its larvae feed, among other members in its family of poisonous, laticiferous plants. Incidentally, the Oleander was also first described by renowned Swedish naturalist, Carolus Linnaeus in 1753. I had the great opportunity of photographing this moth earlier which I documented on this website here and here.
Entire body of this caterpillar was a pleasant apple green, with a straight, dorso-lateral row of small, aqua-marine dots from its second to seventh abdominal segments, with a chalky white, longitudinal band immediately above this. There was also a scattering of distinct, white dots from its first to fifth abdominal segments. Its spiracles were jet black, outlined with white. On its third thoracic segment, there was a prominent pair of ocelli (A marking that resembles an eye), consisting of an outer, Dark Blue ring with a whitish blue center, clearly advertised when its defensive posture (head tucked under) was adopted.
Its tail horn was relatively short and had a rounded tip. There was a sparse distribution of low, short spines over the entire tail horn, which was largely citrus-yellow. It was voraciously feeding on Crape jasmine leaves and excreting large greenish black pellets. Since it was dark we decided to visit and photograph it next day.
Next day morning when we went to visit the caterpillar again we just couldn’t find any apple green caterpillar. Previously apple-green body had transformed to a dirty orange on the flanks and an olive-brown on the dorsum. A symmetrical pair of round, black patches had also appeared on the top of its first thoracic segment, just posterior to its head.
The thick rings of its false eye spots had darkened to a black outline. The yellow of its posterior tail horn had now darker orange. This was pre-pupal metamorphosis of the caterpillar. What we saw yesterday was the final instar version of this caterpillar.As we were observing the caterpillar was descending to the ground. Then it dropped to the ground and started burrowing deep into the soil to pupate. I did not disturb its path and let it continue. In another 10days I was sure it is going to emerge out of its pupa and brilliantly colored oleander hawk moth which I had previously documented on my website.
Descriptions and illustrations of the larva and pupa of the oleander hawk-moth were provided previously by Bell & Scott (1937), with more recent works by Pittaway (1993) and Pittaway & Kitching (2009). Throughout its broad geographical distribution, the combined list of documented larval host plants for the oleander hawk-moth comprises no fewer than 32 genera in 12 families, clear indications of a polyphagous diet. However, there appears to be a strong preference for plants in the family Apocynaceae, with at least 17 genera (more than half) recorded. A most probable advantage of consuming potentially poisonous plants in this family would be the chemical defense that the larvae would be able to derive from them. For example, the leaves and other parts of the oleander contain a potent concoction of cardiac glycosides (cardenolides), such as oleandrin, which can cause nausea, vomiting, weakness, irregular pulse and decreased heart rate. The oleander has even been responsible for occasional fatalities in humans. Thus the plants in the Apocynaceae would confer the larvae considerable deterrence against a variety of predators.
- Beck, J. & I. J. Kitching, 2008. The Sphingidae of Southeast-Asia (incl. New Guinea, Bismarck & Solomon Islands).Version 1.5. http://www.sphin-sea.unibas.ch/.
- Bell, T. R. D. & F. B. Scott, 1937. The Fauna of British India, including Ceylon and Burma. Moths. Volume V. Sphingidae. London.
- Inoue, H., R. D. Kennett & I. J. Kitching, 1997. Moths of Thailand, Volume Two Sphingidae. Chok Chai Press, Bangkok.
- Jarvis, C., 2009. The Linnaean Plant Name Typification Project. The Natural History Museum, London. http://www.nhm.ac.uk/research-curation/research/projects/linnaean-typification/.
- Pittaway, A. R., 1993. The Hawkmoths of the Western Palaearctic. Harley Books, in association with the Natural History Museum (London), Essex.
- Pittaway, A. R. & I. J. Kitching, 2009. Sphingidae of the Eastern Palaearctic. http://tpittaway.tripod.com/china/china.htm
- Robinson, G. S., P. R. Ackery, I. J. Kitchi HOSTSA Database of the The Natural History Museum, London. http://www.nhm.ac.uk/research-curation/research/projects/hostplants/
- Stewart, A., 2009. Wicked plants. Algonquin Books of Chapel Hill, North Carolina.
- van Wyk, B.-E. & M. Wink, 2004. Medicinal Plants of the WorldAn Illustrated Scientific Guide to Important Medicinal Plants and Their Uses. Times Editions-Marshall Cavendish, Singapore.
- Wasfi, I. A., O. Zorob, N. A. Al Katheeri & A. M. Al Awadhi, 2008. A fatal case of oleandrin poisoning. Forensic Science International.
- Wee, Y. C., 2005. Plants that Heal, Thrill and Kill. SNP International, Singapore.