The swallowtails were in general hard to photograph, because they never stopped during the heat of the day. Many species nectared on the wing, tripping daintily over flowers and just dipping in. This first shot shows a male common Mormon, Papilio polytes, doing just that:

Some females of this species have essentially the same colouration as the males, but others mimic one or other of the roses, Atrophaneura sp. This one mimics the crimson rose, Atrophaneura hector:

Here is an awful shot of a real crimson rose:

The crimson rose has a red body, while the Mormon has a dark body.
In Kolkata the commonest swallowtail was the common jay, Graphium doson:

This is quite a small, tailless swallowtail, which glints metallic blue in flight.
In Mysore I found this larger, green, tailless swallowtail, which I can't place:

If anyone has any input on that one I'd be interested to know.
European swallowtails, Papilio machaon, flew in the north and south but I didn't photograph any.
The commonest whites were the Catopsillia species. I think I saw both pomona (the common emigrant) and pyranthe (mottled emigrant) but I only got shots of pomona:

This is instantly recognisable as being similar to the European common migrant, Catopsilia florella. It flew around trees in city centres everywhere.
Two grass yellows were common. The common grass yellow, Eurema hecabe, dominated in the north, and the three-spot grass yellow, Eurema blanda, in the south.

(Common grass yellow)

(Three-spot grass yellow - referring to the number of dark marks in the cell of the forewing)
Endemic to the Nilgir Hills is the Nilgiri clouded yellow, Colias nilagiriensis. This is a male roosting - the only time I found I could photograph a male:

The books say females are rare but I actually saw plenty, and they were easier to photograph:

This species is sometimes considered a subspecies of the European Colias erate, which also flies in India (but not in the Nilgiris).
In the botanic gardens in Ooty I think I saw Indian cabbage whites, but the only white I photographed there was this lesser gull, Cepora nadina:

Elsewhere in Ooty, and in the hills, I saw the common albatross, Appias albina:

This really was the holiday of a lifetime, and I don't mind giving a bit of free publicity to the company that made it possible, Art Safari (http://www.artsafari.co.uk/). The trip was tailor-made to our requirements, we took five flights altogether (Heathrow-Delhi, Delhi-Kolkata, Kolkata-Bangalore, Coimbatore-Mumbai, Mumbai-Heathrow), stayed in 5-star hotels, were met by agents at every airport, had guides and a car and a driver at our disposal at all times, and the cost came to under £2000 a head. That's way more than I would normally spend on a holiday and I will be paying it off for some time, but it's amazing value all the same. The chance to get to grips with the butterfly fauna of another continent, as well as all the other things we did, was wonderful.
Guy