Archive for the ‘Pongamia pinnata’ category

Caterpillar of the Oleander hawk-moth on Tagar

4 January 2011

I recently visited friends in Kolhapur who live close to the New Palace. Their boundary wall with the neighbouring building (like all boundary walls) is lined by a few bushes of which one was a shoulder-high Tagar Tabernaemontana spp). I was surprised to stare right into a pair of blue eyes – these were not on a person but on a large caterpillar. I guessed it was a sphingid (hawk-moth) but not sure which it was. Searching the bushes revealed two large moths each about three-four inches long.

The caterpillar with large blue eye-spots

The moth caterpillars were bright green with two large amazingly beautiful blue-eyespots. The sides had a line of white spots arranged as if demarcating a saddle . On the sides it had small vertical black marks.

First I searched  the Hosts Lepidoptera foodplant database with keywords “Sphingidae” (the family to which hawk-moths belong) and  “Tabernaemontana” (scintific name of the genus to which Tagar belongs). The search gave me four likely candidates. Information on Wikipedia and Encyclopedia of Life enabled me to ascertain that it was the caterpillar of the Oleander Hawk-moth (Daphnis nerii)   and not the other three.

Oleander Hawk-moth (Daphnis nerii) (Image:Viern Vaz on Wikimedia Commons)

The English entomologist W.F. Kirby (1844-1912) writes in his “A hand-book to the order Lepidoptera” that :

The moth is very abundant throughout Africa and Southern Asia, but becomes scarcer and more local in Southern Europe, and migrates northward in Central Europe in warm summers.  Single specimens have been captured in the South of England at long intervals.

This is a fairly easy caterpillar/foodplant combination to identify though it is difficult for beginners to distinguish which species of Tagar the hostplant may be.  Tagar belongs to the plant family Apocycnaceae, which contains many toxic plants. Tagar, I assume,  is also toxic and should give the caterpillar/pupa/moth added protection by seqestration of plant toxins. The usual hostplant of the Oleander hawk-moth is Nerium or Oleander which most of us know is poisonous.

Pupa of Oleander hawk-moth (image:Viren Vaz on Wikimedia Commons)

The Oleander Hawk-moth is also a relatively easy moth to find and rear in India. Most of the images seen here are by my friend, Viren Vaz, who reared them on the balcony of his Chembur home.

Notice : This is a version of an email sent to IndianMoths email group which you must surely join if you are interested in Indian moths.

Advertisements

Pirated pupas of the Common Banded Awl

7 October 2007

On 18 July 2007, I visited Kumargram, a tea-garden, just a handful of kilometers South of the Bhutan border and a few kilometers West of the Sankosh river, the natural feature which separates the West Bengal Dooars from those of Assam.

Nearby was a disused World War II airstrip amidst a tea-garden. I took the opportunity to rummage around during my lunch-break.

While I was there, I noticed a small tree with leaves and branches coming down to my shoulder height. The leaves were jigsaw shaped; something had been at them. Again and again, I found leaves folded to form narrow open tubes held together with a few strands of a fibre.

In each leaf-tube was the remains of a pupa. The pupas were brown, sometimes with green slimy-looking markings. These pupas were more or less heavily covered with a white powder, which I then thought was that of a fungus. The pupas had holes in them – some had large holes at the head indicating the point of exit of a newly hatched butterfly, others with smaller holes at the sides or on the back, the likely exit point of a newly hatched parasite such as a wasp.

I looked around for the butterfly whose pupas it could be, and almost immediately, I saw a handsome robust skipper with large antenna hooked elegantly and ending in sharp points. The head had fine greenish bristles. The forewings were triangular, held straight back and half-covered by well-rounded hindwings. The hindwings had a thin clear white band which was diffused towards the outer side, the distinctive feature of the butterfly. There were four or five of these handsome skippers, buzzing strongly around the bush and settling for short periods of time on exposed leaves or twigs.

I found one perched low, which allowed me to catch him gently between my thumb and forefinger. Knowing that hesperiids require both UP and UN images, I opened its wings for photography, but the best of efforts could not prevent some smearing off of the scales.

Strangely, the UP was a featureless brown. Later on I referred to Wynter-Blyth and Kunte and concluded that it later as the COMMON BANDED AWL, (Hasora chromus). I also found out that the white powder on the pupas was a characteristic of the subfamily Coeliadinae or the Awls.

The butterfly, when released, showed no inclination of flying off, allowing some excellent shots of it on my hairy arm! When I had had my fill of photographing the skipper, I shooed it off my hand. It then resumed flying around, looking, I thought, for some suitable leaves on which, I presumed, to lay eggs.

Now seeing the dismal pupal casts, I looked around for a wasp which could have been the brood-parasite. I soon saw a small, blue-coloured wasp, buzzing lazily along with legs suspended below it.

This I suspected may be the culprit, but I had no net to catch it and it did not settle for me to get a photograph. Anyway, it could have been flying along there by coincidence. The only way to confirm whether this was the wasp predator is by examining parasites emerging from a pupa or by actually observing a wasp piercing a pupa with its ovipositor. I anyway had no more time to spare and reluctantly left the spot.