Daphnis minima

My daughter called me that day to photograph a moth which she thought was Oleander Hawk-moth(Daphnis nerii). When I went close to take photograph I realized that it was not Daphnis nerii. It was looking very similar to Daphnis nerii, but was brownish all over instead of the bright camouflage green Oleander Hawk-moth had. You can see Oleander Hawk-moth here as well as in my Macro Stitching a Moth post. You can also see its caterpillar at Metamorphosis.

I photographed this moth using my Canon EF 100mm f/2.8L Macro IS USM on Canon EOS 5D mark II with Rayflash fitted to Canon Speedlite 580EXII Flash. All photos were taken hand held at an awkward angle perching on a wooden stool as the moth was sitting close to fluorescent tube light outside my house. Ant which passed by during the shoot gave nice dimension of scale to the photograph.

Daphnis minima

Later going through identification I found that it did not even resemble another likely candidate Daphnis hypothous. Later at Indian Moths Yahoo Group I found out that it is Daphnis minima. This species is endemic to the Western Ghats and Sri Lanka. I thank Dr Ian J. Kitching and Roger C. Kendrick For helping me out in identification.

For more details on Daphnis minima check this link.

Gastropacha Species of Lappet Moth

Lappet moths are a very interesting group of moths. As we saw in the first part of this 3 part series called Lappet Moth – Trabala Species. We also noticed in the second part Trabala in Trouble. Now let us see the adult version of a species from this group. This fascinating moth resemble a dried leaf when at rest. This moth belongs to Gastropacha species of Lappet moth (Lasiocampidae) family. I found this at night under Mangalore tile roof my house staying motionless like a dry leaf. When I picked it up to get closer look it excreted a smelly liquid from its caudal end probably to startle me. It remained motionless despite all the disturbances like a dry leaf. they have a snout which resembles the stalk of the dry leaf, combed antenna is fold back on the body.

Predators of this moth are the bats, and they do not see these moth like we do. They see them through sound waves by echo location. In fact the scales of this moth is so modified that ultrasonic signals used by bats to locate these moth just fails as the scale in this moth absorb those signals. The wing scale cover reduces the potential of the ultrasonic signal reflected from these moths of Gastropacha species. Absorption of a considerable part of the reflected signal decreases the sound pressure. This property of the wing scale cover enables the moth to prevents bat from finding the moth in the night. It is invisible to us as well as bats by this great camouflage.

Gastropacha resting on a stick

Camouflage, whereby animals seek to look inanimate or inedible to avoid detection by predators and prey. There are many examples of rainforest species which are cryptically colored to match their surroundings. For example, the Uroplatus geckos of Madagascar are incredible masters of disguise and are practically unnoticeable to the passer-by. An even more amazing group is the katydids, a group of grasshopper-like insects found worldwide. Katydids are nocturnal insects which use their cryptic coloration to remain unnoticed during the day when they are inactive. They remain perfectly still, often in a position that makes them blend in even better. Katydids have evolved to the point where their body coloring and shape matches leaves?including half-eaten leaves, dying leaves, and leaves with bird droppings?sticks, twigs, and tree bark. Other well-known camouflage artists include beetles, mantids, caterpillars, moths, snakes, lizards, and frogs.

Some species appear to have conspicuous coloration when they are not in the proper surroundings. For example, among the brilliant butterflies of the forest, the magnificent electric blue Morpho, has iridescent blue upper wings and a seven-inch wingspan. However, because the underwings are dark, when the Morpho flies through the flickering light of the forest or even out in broad daylight, it seems to disappear. Other forest species, especially mammals, have spots or stripes to help break up the animal’s outline. In the shade created by the canopy, large mammals like leopards, jaguars, ocelots, and okapi are surprisingly difficult to see with their disruptive coloration.

Gastropacha from top

There is a strong evolutionary pressure for animals to blend into their environment or conceal their shape; for prey animals to avoid predators and for predators to be able to sneak up on prey. (Exceptions include: large herbivores without natural enemies; brilliantly-colored birds which rely on flight to escape predators; and venomous or poisonous animals which advertise with bright colors.) Cryptic animals include the tawny frogmouth (feather patterning resembles bark), the tuatara (hides in burrows all day; nocturnal), some jellyfish (transparent), the leafy sea dragon, and the flounder (covers itself in sediment).

The distinction between camouflage and mimicry is arbitrarily defined in that mimicry requires that the “model” be another organism, rather than the surroundings; the arbitrary nature of this distinction between the two phenomena can be seen by considering animals that resemble twigs, bark, leaves or flowers, in that they are often classified as camouflaged (a plant does constitute the “surroundings”), but sometimes classified as mimics (a plant is also an organism). Either way, the animal is considered cryptic.

Gastropacha on a paper

Camouflage is usually most effective when an animal is still. Cryptic animals that forage during daylight may be ambush predators, taking advantage of their ability to blend into their background. Alternatively, cryptic animals may be active predators in darkness and use their crypsis while inactive. Some cryptic animals also simulate natural movement, e.g., of a leaf in the wind. This is called procryptic behaviour or habit. Other animals attach or attract natural materials to their body for concealment.

Parasitoid Wasp Pupae on Tarbala Caterpillar

In the last blog I explained about Trabala Species of Lappet Moths. Few days back I found another Trabala caterpillar. This one was infested with pupae of Parasitoid wasps all over its body. It was lethargic and was unable to move.

In general though most people still use the term Parasitic Wasps. Technically speaking, they are not actually parasites – they are parasitoids. This is because a true parasite is something that lives at the expense of its host but doesn’t actually kill it, whereas parasitoids nearly always kill their host.

Parasitoid larvae usually develop by feeding on a single host – different species develop on anything from tiny aphids and insect eggs right up to large butterfly and moth larvae. They can live and feed inside the host’s body cavity (endoparasitoids) or outside the host’s body (ectoparasitoids). They can be solitary or gregarious – with anything from 1 to many 1000’s of larvae consuming the same host.

Parasitoid Wasp On Tarbala Closeup

Fascinating life strategies

Nearly all parasitica inject venom into their host along with or just prior to the egg. This venom is a highly complex mixture of chemicals and other agents used not just to paralyse the host, but to also modify the host’s tissues. Tissue modification is a feature of nearly all venoms, making the host more nutritious for the developing wasp larva and helping to overcome the host’s immune systems. The latter is an especially important consideration for internal parasitoids as a host’s body will usually try to surround (encapsulate) a foreign body to prevent infection and to kill any parasitoid eggs or larvae. Parasitica have developed many ways of getting around this but I think the most devious must be the use of polydnaviruses (also known as Poly-DNA-viruses) . These viruses are injected by some endoparasitoids with the venom and have been shown to target and disable the host’s immune system – thus protecting the developing parasitoid. Other, more basic, methods of bypassing the host’s immune system include laying the egg directly into the host’s brain (ganglion), where the immune system is unable to encapsulate it.

Whichever method the parasitoid uses to prevent encapsulation it must also protect itself against many other dangers. One of the most serious being the possibility that a host will succumb to a fungal or bacterial infection and die before the parasitoid has finished with it. To prevent this, many larvae secrete chemicals with antibiotic or antiseptic properties as they move around the host’s body cavity. They also avoid damaging the host’s gut (a massive source of bacteria) by eating non-essential areas first, like body fat and the reproductive organs. Many species also use teratocytes – bundles of cells that emerge from the egg with the embryo. These cells absorb food from the host’s body cavity and the parasitoid larva feeds on them – removing the need for it to feed directly on the host’s tissues until it is absolutely necessary.

Parasitoid Wasp Puape On Tarbala Caterpillar

Polyembryony is another complex strategy employed by parasitica, but this time its aim is to ensure the maximum number of offspring from the fewest number of eggs. Some species lay a single egg that continues to divide, cloning itself into many independent larvae – in extreme examples one egg can produce thousands of larvae. Some species have even been shown to produce different types of larvae from the same egg – normal larvae that feed and develop fully into adult wasps and others, which never mature into adult wasps, that act as guards to protect the others from attack by other parasitoid larvae.

Charles Darwin even used one family of Parasitoid wasps as evidence for natural selection, writing to a colleague:

I cannot persuade myself that a beneficent and omnipotent God would have designedly created the Ichneumonidae with the express intention of their feeding within the living bodies of caterpillars.

So what next turn will you see in the story of lappet moths, wait for my last installment on 3 part series on Lappet moths.

Final instar of Oleander Hawk Moth Caterpillar

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.

Oleander Hawk Moth Caterpillar

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.

Defensive posture

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.

Defensive pose of Oleander Hawk Moth Caterpillar

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.

Pre Pupal stage of Oleander Hawk Moth Caterpillar

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.

Pre-Pupal Stage of Oleander Hawk-Moth Caterpillar

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.

Reference

• 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.

Fatal Attraction

I was trying to test Canon EF 300mm f/4.0 L IS USM which was courteously provided by Shivashankar with my Canon EF 1.4x II Extender when I spotted these mating Common Grass Yellows(Eurema hecabe) on a Peacock Flower (Caesalpinia pulcherrima) plant. On closer inspection there was this dark brown spider stuck on the head of the male. I wanted to capture the whole sequence so I quickly changed to my Canon EF 100mm f/2.8 USM Macro with Canon MT-24EX macro twin light flash and captured the whole sequence. I have posted 4 most interesting shots from this sequence.

Fatal Attraction

This Adanson’s House Jumper (Hasarius adansoni) had caught hold of the male by the head while in the act of mating. It had killed it and is now proceeding towards the female which was still stuck to the mate.

Fatal Attraction

It was a precarious perch for the spider as it had to manage the dead body of one and struggling butterfly on the other. The female was desperately trying to escape from the clutches of the spider but was unable to do. Spider manage to twist and turn the body of the dead male and lurched forward to reach for the female.

Fatal Attraction

After nearly 15 minutes of struggle the female managed to tire out the spider and gain the upright position. With bit more struggle she was able to release herself from the mate and fly away free and alive. It was such an awesome sight that I was amazed how she managed to do that.