Papilio xuthus continued 1

Alright, as promised, here is the sequel. So I stayed up with my pupa till early in the morning, watching as a new butterfly slowly formed inside. The process is slow, with the pupal stage taking altogether 12 days, but toward the end you can see changes by the hour. About halfway through the pupal stage, or about 6 days, you can see the development of eyes within the pupa. If you hold a really strong light behind it, you can see these dark spots developing where you'd expect the head of the butterfly to eventually reside. The 12 days is variable, as pupal development is influenced in part by temperature. The warmer it is, the faster the pupa develops into a butterfly.

In this picture above, at the top of the pupa there are these pointed projections on either side of the "head", and right below them are the dark eye spots. From this, you know that you are going to get butterflies in a few days, and that he pupa didn't go into hibernation, as they sometimes do (that's a topic for later).

Here's a view of the same pupa from the side. When a pupa first forms, the top half is all transparent green when you hold it up to the light. Only a portion of the abdomen is dark. As time passes and the butterfly forms inside, the tissues stop being transparent. In this picture, the head, part of the future thorax, and the top half of the wings are starting to form.

This is within 24 hours of the butterfly emergence now. You can clearly see the forewings (the hind wings are hidden underneath the forewings), and not only that, you can see yellow spots on the forewings. There are also black stripes forming on the sides of the abdomen. The next several shots are sequential photographs from when the butterfly actually emerged from its pupa, at 3:17AM. The whole process takes less than a minute! It uses its wings and legs to push open a triangular flap at the top and front of its pupa shell, and uses its legs to grab onto whatever is nearby, and pulls itself out of the shell.

After that, it has to pump fluid into the veins of the wings to expand them. It has always amazed me how the final wings can be so big, considering how small and crumpled the wings are when it first emerges. The butterfly usually hangs vertically during this time so that the wings expand also with the aid of gravity. This also ensures that the wings are straight after they've formed and dried. After about 15 minutes, the wings are fully expanded, but it takes another 2 hours or so before they are dried and stiff enough to support flight.

This picture is slightly out of focus because this butterfly was crawling and flying around, and really wouldn't hold still for me. I now anxiously wait for the other two butterflies to emerge. Oh and in case you are wondering, it's a boy. :) The females have a lot more blue coloration on the hind wings. Hopefully one of the other butterflies will be a female so I can post pictures for comparison.

Papilio xuthus

Papilio xuthus is a butterfly in the swallowtail family, commonly found in Asia (its common name is the Asian Swallowtail), but also found in Hawaii. There is some debate as to how it got there, whether it was introduced by accident, on purpose, or made it there all on its own. Most believe it was introduced accidentally. This species was first observed on Oahu in April 1971 and then on Maui in May 1974. Today, it can be found on all the major Hawaiian islands. It can be found in all stages of development year round in Hawaii, as there is essentially no winter. Winter in Hawaii is characterized by shorter day length, but even so the temperature is usually in the mid 20's Celsius - not exactly frigid.

This caterpillars of this species feed on citrus and related plants (family Rutaceae). I recently raised 3 eggs on Citrus x limon (lemon) and Citrus x sinensis (sweet orange).

This little yellow sphere is the egg of this species. It's tiny, about 1 mm in diameter, but they're not hard to find if you know what you're looking for. Against the green background of this citrus tree on Kaua'i, it stands out. This egg was found on November 22, 2012. The eggs can be laid on the top or underside of leaves, but usually near the edge of the leaf.

At the center of this photo, you can see an egg, except it's not yellow anymore, but a translucent white. That's because the caterpillar has hatched and is gone! Usually, once the larvae hatch, the first thing they do is eat their old eggshell - it's a hearty first meal. However, sometimes for whatever reason they don't, or perhaps they were eaten by predators before they could get around to eating the eggshell. At this small stage, their main predators are spiders, ants, and the like.

In the center of this photo, I've captured a 1st instar caterpillar in the process of hatching. Half its body is out of the shell, and the other half isn't. Caterpillars moult several times after hatching, before becoming a pupa (aka chrysalis) and finally a butterfly. Most moult 5 times, but this number is variable depending on the species. The stage between moults is known as an instar. Thus, after hatching and before it has moulted for the first time, the larva is in its 1st intar. The plant you see in the picture is a lemon tree seedling.

This photo shows two newly hatched 1st instar larvae. The little guy on the left is eating his eggshell. The one on the right has just hatched moments ago, and is taking a rest, but eventually it will eat its eggshell too. This behavior is not uncommon amongst butterflies. These larvae are about 2 mm after they hatch. It sounds small, but considering how small the egg is, I'm surprised they are as big as they are.

After about 3 days of eating, they've doubled their length (which means they've increased their volume by a factor of 8) and are a huge 4 mm! They then moult. The one on the left has just done so, and the little round black thing you see in front of it is the old head capsule it had to shed along with its skin. It is now a second instar caterpillar. You can see the chew marks on the lemon leaf. It doesn't seem like they eat a lot now, but wait until they're in their 5th instar, 3 caterpillars can defoliate a small seeding a couple of feet high. The larvae are essentially just eating machines. It's basically all they do. Avoid predators, eat, rest, poo, repeat as needed until they get to a big enough size that they need to moult again. Sounds like a pretty good life if you ask me....well, except for the predators part in the wild. In my home though, they have no natural predators, and so yeah, it's pretty sweet. This is what retirement must be like.....

This is what a 3rd instar caterpillar looks like. The coloration has changed a bit, and it's about 9 mm in length now. By the way, the caterpillar looks this way because it's trying to look like a bit of bird dropping, and it's one of the strategies it uses to avoid predators. Despite this, only about 1% of the eggs laid in the wild survive to become adult butterflies.

After some more eating and growing, it's ready to moult again into the 4th instar. It stops eating for about a day in order to prepare, and will lay down a small mat of silk to support itself. Then underneath the current skin and head, it will grow a new head and skin, and once it's ready, it will literally crawl out of the old one. In this picture above, you can see a bit of a bump behind the black head capsule. That is the new head developing underneath.

The 4th instar caterpillar is about 1.5 cm long. Doesn't look much different than before, but just a bit bigger. It's still trying to pass itself off as a large bird dropping to avoid predators.

Alright, now this is the best part. This is the final stage, or 5th instar, and instead of a bird dropping lookalike, the caterpillar has transformed into this marvelous green creature with spots and stripes and fake eyes behind its real head capsule. Pretty cool right? This is where it will do most of the growing, and a caterpillar will defoliate a small branch of probably a dozen mid sized leaves.

The larva eats and eats, and is now fairly big. You can see the change by comparing the length of the caterpillar to the size of the head, which doesn't grow along with the rest of the body. You can see that it's a lot larger now than in the preceding picture.

It will ultimately grow to just over 4 cm when mature. Then, it will pupate, which is a really amazing process.

Here's a group shot of all 3 of them when they made it to the 5th instar. Even though they all hatched within a few hours of each other, as they grew, some obviously grew faster than others. The size differences are pretty evident in the group shot.

Before it gets ready to pupate, it will stop eating and clear its guts of whatever is left in there. Usually this is a slightly loose bit of stool (the technically term for caterpillar poop is frass). In some species, this last poop will be totally watery, but in this species, it's semi-solid. After that, it will wander around several hours looking for a place that it thinks is a good pupation site. The caterpillar will then lay down a mat of silk, which you can see on the twig in the picture above. At one end of this mat, it will spin a raised bump of silk, to which it will attach its anal prolegs (basically its bum). At the other end, it will spin a thin but strong silk girdle, and it will slide itself through it.

As it's getting ready to pupate, the various tissues inside the body of the caterpillar start to break down, for they have to re-organize themselves in order to form the adult butterfly. As this happens, the legs are no longer legs, and can't hold on to the branch any more, as shown above. It stays attached to the twig by its anal prolegs anchored to the silk pad, and at the front, it's supported by its silk girdle, which is barely visible in this picture.

After about 24 hours, it sheds its skin, which is really cool to watch. I have it on video, but it's too big to load, and I don't have any sequential pictures for this species to show the process. I do have it for other species, so stay tuned. Anyway, this is what the pupa looks like for this species. You can more clearly see the silk girdle I mentioned earlier that's supporting the mid portion of the pupa. It's a pretty good camouflage amongst the leaves and twigs. The new pupa is really soft, and it takes about another 24 hours for the outer casing to harder. During this time, they're pretty fragile and it's probably best not to poke and prod them too much.

Eventually, all 3 of the eggs I found successfully transformed into pupa. I had 5 lemon seedlings about 20 cm tall, all of which were complete decimated. They had zero leaves left. I suspect some will die, but a couple of the seedlings are starting to recover and grow new leaves. I also had a two year old orange tree that was probably 3 feet tall. It lost about half its leaves. Next time, I'll be better prepared!! So right now, all three pupae are sitting beside me on my laptop table, and one is nearly ready to emerge as a butterfly. It will happen some time today. I'll post more pictures as soon as I can!

Hello

Hello world. This is my first blog, and indeed the first entry in my first blog. Ever since childhood, I've always loved nature. I was one of those kids who didn't mind getting dirty, would walk through parts of the forest where there were no paths, climb trees, and flip over rocks and turn over leaves to see what was hiding underneath. As I grew older, I was drawn in particular to Lepidoptera, that is, the group of insects that includes butterflies and moths. Their life cycle is really amazing, and for anyone who has ever seen a butterfly emerge from its pupa, well, it's just pretty spectacular to see. The first time I saw this event was probably when I was around 15, and it was for a Monarch butterfly. Ever since then, I've been hooked, and I've tried to find as many species as I can, and see as many of their life cycles as I can. Over the years, I've raised a number of species and documented their life cycles, and that is going to be the purpose of this blog - to share that experience. I want to share my knowledge, my pictures, my memories, and who knows, perhaps some other kid not unlike my younger self will come upon this and become interested in these amazing insects.

I do not intend for this blog to be overly rife with scientific jargon, but there will be some because that's just what comes naturally to me now. However, you don't need to have a PhD in entomology to understand my entries. They will take the form of stories in a way, where I take the reader through what it's like in the life of a butterfly basically. I'll try to explain as many of the scientific terms as I can along the way.

Stay tuned for entry two....!