Hello,
I'm Thierry from New Caledonia.
Thank you very much for your interest about the Papilio montrouzieri, which is for me one of the most beautiful species here.
This lovely butterfly flies all year, and in all biotopes. As sometone said, you can find it flying around in gardens in the capital, center of the city. This is a common specie, but not so easy to get. Best way is to catch them when they feed on pentas flowers, or others...
Problem is that most of them are damaged, not easy to get an A1 quality spm...
So I've started to breed them a long time ago to get perfect A1 specimens.
Now I'm careful, because as Olivier said, this buttefly is protected by our local Environmental code, in north and south Provinces, but still not protected in the Loyalty islands Province.
I don't know why they put this specie on the list of threatened and protected species, this is ridiculous as this is an ubiquist and you can find it on the islands, on the mainland, everywhere.....just one insect on the list, and they put this one....a shame....so many other species should be protected, more than this one...
The risk to get one and be controlled by customs, police or so...is a bit important, as you can go to jail for 6 months, and pay a fine about 10000 USD !!!...that's why this butterfly is more and more hard to find on market for selling or exchanging....local collectors are very careful now...
About the forms, they are quite old and were described by two authors :
1) ulyseLlus form (Westwood 1861) : this one shows more blue on the wings. Some specimens can be very blue, more than 90% of the surface of wings.
2) Westwoodi form (Oberthür 1879) : for this form, blue parts are reduced.
The most common form is the Westwoodi one, more than 90% or the specimens caught in the wild and bred.
The ulysellus form is more present when it's very hot, in summer time, from december to february, or bit later...
For me they are not real distinct forms, as when you make a large sery of specimens, you can see spms from the less blue to the more blue ones, with a lot of variations. You can not see real distinct forms.
I think this is just a seasonnal variation due to the heat.
As you know, many species can show different variations looking to the environmental conditions, the kind of hostplant, period, etc...
I've noticed similar variations on many species here, like the Hypolimnas bolina nerina, which shows the best and impressive variations and forms, when it is bred with a lot of heat, and pupae exposed to the heat. I got extreme variations on pupae let on top of my bytterfly house, at 3,5 meters high, where temperature can reach 35°C sometimes, especially from november to january, summer time.
Same results on Hypolimnas octocula elsina, with a light form with more orange during hot period.
We also experienced a similar situation the first time we bred the Graphium gelon, another endemic and hard to get specie. Bred specimens shown a fade green color, not bright, not metallic at all. In the nature, the specimens shows metallic green bands. As the main host is a very tall tree, generally above canopy in direct sunlights, and looking to the behavior of larvae and pupae which are exposed directly on top of branches, I think they need a lot of sun rays exposure to shows these lovely metallic green bands. In some other tropical countries, I heard they met situation on other Graphium species into butterflies houses...
Still on the G.gelon, we also have two forms here :
1) Megasthenes (Mathew 1889) : the "normal" form, with metallic green bands on HW and FW
2) Taeniolata (Le Cerf 1923) : this form is only present on the Loyalty islands, the metallic green bands dissapears, some spms just have a few green and small spots, some no more spots at all, just brown wings with nothing !....
Same thing for Hypolimnas octocula elsina, on the islands, there's a dark form, really more dark than the normal one.
And other species shows some "melanic forms".
These melanic forms are variations due mostly to the thermic amplitude. On Maré island, we find the most extreme variations, and this is the most coldest island, with some temperature which can reach 4 - 5°C at night end July-August, and more than 22°C the day time.
I'm more a moth specialist and I've noticed same thing on some moth species, especially the endemic sphingid : Psilogramma lifuense.
I thought I've found a new sp on Maré island, sent the spms for DNA and genitalia analysis, and the answer was : same specie, melanic form !....
The Psilogramma complex is known, I've read some posts on this topic once, and the consequences are that some authors described a lot of new species which finally are just melanic forms, natural variations.
I think we need to be very careful with the question of forms and also subspecies....limits are sometimes very very tight....
For people who are interested, some of my pictures from breedings, etc are on this internet site (ENDEMIA, a local site about flora and fauna).
Here's the link for P.montrouzieri :
www.endemia.nc/faune/fiche1422.htmlI hope I've answered to all questions...
All the best.
Thierry
...perhaps that could be a way to breed them more largely....thanks in advance. 
