South Africa’s largest butterfly, Papilio ophidicephalus phalusco, the Emperor Swallowtail, Life History
The largest butterfly in Southern Africa is, without doubt, the Emperor Swallowtail (Papilio ophidicephalus). The insect is found throughout the mist forests in Southern Africa (through into East Africa). In South Africa we have a number of sub-species, ssp phalusco is found in the Eastern Cape and KwaZulu-Natal as far north as Greytown, ssp zuluensis in the Eshowe area, ssp ayrsi in the Northern KZN into Southern Mpumalanga, ssp transvaalensis in the Drakensberg and Wolkberg Notrh of the Oliphants river and ssp entabeni in the Soutpansberg way up there in the Limpopo Province. There are a number of other ssp including the nominate further North but we shall stick to ssp phalusco, the one that I know most intimately myself being an inhabitant of their range.
Before I carry on, this post shall not go into detail regarding the length and duration of the instarts (period between skin sheds), as this has all been documented at length by the likes of Clarke and van Son. Instead I shall discuss what I observed during the short eight weeks of the cycle from egg to adult.
My old friend Clive Curtis has always been very pationate about butterflies. We have travelled all around the province together colelcting and breeding butterflies and he is currently working on a DVD about South African Butterflies (www.safarivision.com). Part of the work toward this is documenting the life histories of a particular species in each family. Clive chose the most spectacular of our swallowtails (P ophidicephalus phalusco) as one focus species to breed. He captured a female in the Karkloof had her lay about 20 eggs and past 15 on to me to breed at home.
The Papilionidae (swallowtails) are spectacular insects. All South African readers will know the Orange Dog (Papilio demedocus demedocus) or Green Banded Swallowtail (Papilio nireus lyaeus) from their gardens. These two breed on, amongst other plants, the Citrus species such as lemon, grapfruit and orange trees. Our species, the largest of all, is a far more selective eater. It eats a plant known as Clausena anisata (known as Perdepis in Afrikaans, loosely translated as Horse pee due to its smell when you crush the leaves). Anyway, the first stage of the life history is the egg. Eggs are laid lingly on leaves of the foodplant. The eggs are circular, cream coloured and between 1 and 1.5mm in diameter. It takes the little larvae take about five or six days to mature to eclosure or larval emergence. Just prior to the little larva breaking out of the egg it darkens up. Upon emerging from the egg the larva has its first meal, the old egg shell. To gat an idea of size the larva is approximately 2mm long on emergence. So, to photos, the first photo is of the egg while the second is of the young larva eating the egg shell.
OK, after the little creature eats its shell it settles into life as a butterfly larva. This is a dangerous life, birds, robber flies and spiders want to eat you, wasps and flies want to sting you and lay their eggs in your little body and have their babies grow in you (while you are still crawling around and eating). You are not equiped with very much to evade these hazards, you cannot crawl fast but you can hide. From the moment that these little larvae start to eat they begin to look like a piece of bird dropping. From the first to the fourth instar they larvae look like a bird dropping. They stay on the leaves, eating, growing and shedding skin until, after approximately four weeks they reach the final instar that is different. Of interest is that, during the third and fourth instars, the larvae rest with a slight twist to their body (see the photos below). Anyway, here are photos of the second, third and fourth instars.
The final instar is very different. Rather then resting on the leaves they spend their sleeping time at the base of the tree or branch. This means that they no longer need to resemble something grim like a bird dropping and are supprisingly different with beautiful green and brown patches on the skin. The lumps and bumps are still evident (indeed into the pupal stage). Of interest, the Papilio butterflies have a defensive mechanism, a foul smelling structure known as the ostometrium that it pops out of its head when threatened. As said they smell foul and obviously tell all attackers that they are not a pleasant tasting meal at all. Below are a number of photos of the final instar (and a couple with the mutters with their ostometrium exposed)
The most magical of all butterly larval stages has to be larva to pupa to butterfly. After 7 to 14 days as fifth instar larvae they get nice and fat and lethargic. The process of change begins. They slip off and find a safe place to spend the next two or three weeks as a vulnerable pupa. The Papilio butterflies all have a girdle holding the pupa in place. Like most other butterflies they spin a silk pad which that they attach themselves to (by anal appendages known as cremaster hooks). They also spin a girdle which is a little like you undoing your belt and slipping it around a branch and the fixing it. It allows you the spend your pupal stage, head up leaning back. The pupa is splendid, rather like a twig with a bit of lichen underneath.
Finally, after two to three weeks (and longer during winter) the adult emerges. Not much more can be said of the butterfly, most people have seen it. It is safe to say, and an awful cliche, that, like most jouneys the destination is great but the route is enlightening. The path to adulthood of these beautiful butterflies is full of risk. The response is a wonderful evolutionary result where larvae and papae are beautifully cryptic. Below are shots of a freshly emerged male.
Anyway, I must conclude by saying that if you want to see these butterflies, it is easy. All you need to do is get into open spaces within the mist forests on a sunny day in Summer (peak in November/December and again in March/April) and you will see them flitting around. An old trick is that they love the colour red. About 20 years ago I purchased a car for its colour, a bright red VW, and it was perfect to attract Papilio butterflies (especially P ophidicephalus and P euphranor) to come closer.