Battus philenor philenor

Battus philenor (Pipevine Swallowtail) is a really unique looking butterfly in North America, which is hard to mistake for anything else. This butterfly belongs to the genus Battus (no relation to bats) which is mostly found in Central and South America. In North America north of Mexico, there are only two representatives of this genus, the other being Battus polydamas (coming soon!). All butterflies in this genus feed on plants in the pipevine family (hence the name), which is scientifically known as the family Aristolochiaceae.

This family of plants contains distasteful toxins, and most other bugs avoid eating pipevine. However, the butterflies in this genus have evolved to take advantage of this plant family. Instead of avoiding it, it eats the plants and then stores the toxins in its own body, and then gains protection from vertebrate predators as a results. The female butterfly also lays eggs which contains these toxins, and so even the eggs get some protection. Additionally, many other butterfly species in North America, which share a similar distribution range, have evolved to look similar to this butterfly, attempting to gain some protection as well.

This butterfly can be found all over the southern half of the USA, with occasional migratory incursions into southern Ontario in Canada. Every once in a while, one will see reports of this butterfly in other parts of Canada, but these are very rare strays, and even in southern Ontario, this butterfly is not expected to be seen in great numbers in most years. There are two subspecies distributed in the USA and Canada. In California, subspecies hirsuta is present, feeding primarily on Aristolochia californica. Everywhere else in its range, we find subspecies Battus philenor philenor. This butterfly can feed on many plants in the pipevine family, depending on what's available in a certain location. Some common host plants include A. macrophylla, A. tomentosa, A. serpentaria, A. reticulata. Three additional subspecies are found from Mexico through to Guatamala and Costa Rica (acauda, orsua, and insularis).

Eggs are a rust red and laid in clusters. The young larvae prefer to eat young tender leaves, and the eggs are therefore usually laid on young shoots or tendrils.

These caterpillars are very coordinated, and hatch and eat and moult in near unison. I'm not sure how this happens, and I'm not sure anyone knows yet, but they are all probably synchronized by chemical means. When they first hatch, they are tiny, and you can't see much detail. They are brown with little bumps. At higher magnification, you can see little hairs sticking out from these bumps.

These larvae eat a large amount for their size and also grow quite fast. The egg clusters are usually about 10-20 in size, so that doesn't help either, because if you're going to try to raise this species, you can't just raise one. You pretty much have to raise the whole lot. So if you're going to try this, make sure you have enough pipevine plants around. This above picture shows a cluster of second instar larvae. You can see a bit more detail now, and the caterpillars have slightly larger bumps which are tipped with orange.

Unlike some other swallowtail larvae which show dramatic color changes as they mature, this species does not. As they grow, the bumps and filaments get larger, but the general color scheme stays the same. The larvae are uniformily brown, and have a multitude of filaments and tubercles, with most of the ones in the mid body being tipped with orange. This third instar larva is about to moult. Notice the translucent bump behind the black head capsule. That`s where the new head capsule is developing.

These are fourth instar larvae. Starting at about this stage, they start to disperse a bit. They no longer feed in huge groups, but form smaller congregations or start to feed in solitude. This behavior likely reduces competition for food amongst the larvae.

When fully grown, this caterpillar will be nearly 5 cm in length.

The larva empties its guts and then wanders around for about half a day. After it has settled on a good spot to pupate, it will make a raised silk pad on which to attach its anal prolegs. The picture above shows the caterpillar in the process of building this silk pad, which is that blob of white stuff near its mouth.

After a bit of rest, it will then proceed to construct its silk girdle, which will support it across its mid section when the larva transforms into a pupa. This process takes about 30-45 minutes. Like many other swallowtails which have adapted to survive winters, the pupae of this species may take on two color forms.

The green form is a bright beautiful green, designed to blend in with leaves. Usually, pupae of this color tend to develop into adult butterflies right away, and do not hibernate.

Pupae can also be of the brown form, though to tell you the truth, it`s not really brown. It`s more a purple pastel color. This form usually blends in with twigs and dead leaves, and will usually hibernate (aka diapause) through winter, only to emerge the next spring.

As the butterfly develops within, you will slowly notice that the pupa turns from it`s normal color to black, which is the predominant color of the wings of this species. As it gets closer to emerging from the pupa, you will actually be able to recognize the wing patterns of the future butterfly through the pupal shell. The above picture was taken just as a newly emerging butterfly is pushing its way out of the pupa.

The newly emerged butterfly will find a place where it can hang, so that the wings can expand and straighten with the aid of gravity. The wings take about 10-15 to expand, as the butterfly pumps the veins of the wings with body fluid. It will then take about 2 hours for the wings to become hard enough to sustain flight.

From top to bottom are male (dorsal and ventral) and female (dorsal and ventral) specimens. I kept a few of the butterflies I raised, but let most of them go. I`m not sure how many, if any, survived in the wild. The ones I released as nearly full grown caterpillars were often not relocated when I checked on their food plant later. Either they were really good at hiding (though I`m pretty good at spotting them), or they were eaten. Despite the protection they should gain by the toxins stored in their bodies, the defense isn`t perfect, and the vast vast majority of butterfly larvae die in the wild at the hands of a myriad of predators. Besides, if that were not the case, we`d be overrun with Pipevine Swallowtails.

Papilio polyxenes asterius

Papilio polyxenes asterius (Eastern Black Swallowtail) is a very common and widespread butterfly in North America. In part, this is probably because this butterfly feeds primarily on plants in the family Apiaceae, which includes parsley, dill, carrot, celery...etc. Many of these plants are found in urban gardens, and wild carrot is a common weed (at least, it's a common weed where I live). So, there's basically no shortage of food plants for the larvae of this species. This butterfly can be found in central and eastern USA, as well as in southern portions of Canada, primarily in Manitoba, Ontario, Quebec, and some of the southern maritime provinces.

For me, this has always been one of the easiest butterflies to raise, not only because they can be attracted to most home gardens, but I find the females aren't shy about laying eggs. Some butterflies, like Papilio glaucus (Eastern Tiger Swallowtail) need certain conditions to induce oviposition (egg laying), including a certain amount of sunlight, temperature, and enough space in which to fly around and find the host plant. While Papilio polyxenes asterius may not be hurt by those optimal conditions, I've found that it often doesn't need that perfect combination either. I recall fondly once when I was still in university, where I caught (by hand!) a female specimen on campus. I bought some parsley from the grocery store, and just put the butterfly on the parsley bunch and that was all it took for it to lay eggs. Over two days, it laid about 120 eggs, and I raised all of them! She probably could've laid more, but I didn't think I could handle any more after seeing what she did after just two days of egg laying, so I released her into the wild.

The eggs are spherical, about 1 mm wide, and is shown in the center of the above photo. Depending on temperature, the egg will turn dark over the course of several days, and a caterpillar will hatch. This species has five larval instars.

It's dark, with a white saddle in the middle, mimicking a small amount of bird poo. This, as you will find out, is a common theme amongst swallowtail butterfly larvae.

After about 2 days of eating, it moults into a second instar larva. It's still black with a white saddle, but you can also see tiny bumps on the larva which are surrounded by an orange/red base.

The third instar is a bit bigger, but not much changed in terms of color.

This is the fourth instar larva. It's now a nice green with black stripes that are interrupted by yellow dots. Many swallowtail larva undergo such a color change for its fourth or fifth instar, whereby they no longer mimic bird droppings, but become various patterns of green to blend in with the foliage. It still has some small black bumps all along its body.

This is a fully grown larva, the fifth and final instar. It's now totally smooth, with no bumps anywhere. When fully grown, it will be about 4.5 cm long. It gets to be a pretty decent size, but it doesn't seem to eat as much food as some other caterpillars that reach a similar size, in my experience. This guy isn't starved or malnourished at all - look at those chubby prolegs! The stripes and dots pattern help break up its outline and helps it camouflage - it's similar to the spots on a cheetah.

When it's done feeding, it will evacuate its guts with a semi-solid greenish stool, and then find a place to pupate. Like other swallowtail caterpillars, it attaches its bum to a pad of silk, and then builds a silk girdle to support its mid section.

Pupae can be either green or brown. Green pupae tend to happen in the summer, and is for blending in with green foliage. Brown pupae tend to results from larvae which develop toward the end of a growing season, and are likely to hibernate. Having said that, both color forms occur in any population and at any time, so this isn't a hard and fast rule. Certainly, brown pupae can produce adults without going into hibernation first. This pupa eventually produced a female butterfly which was released.

Going from top to bottom are two males, dorsal and ventral, and two females, dorsal and ventral. Females tend to have less yellow overall on both the upper and under surfaces, and females also have more blue coloring on the upper side of the hind wings. There are many butterflies that look similar, and it is theorized that they are all mimics of Battus philenor philenor (Pipevine Swallowtail), which is distasteful to birds. By looking similar, they may gain some protection, as birds will avoid both Battus philenor philenor and these mimics.

If you'd like to try your hand at this, just plant some parsley, and sooner or later, these butterflies will show up (if you live in an area in which they naturally occur - this information is easily obtained via the internet). If you happen to be less than successful at attracting them to your garden, at least you can enjoy fresh parsley from your garden.

Agraulis vanillae nigrior

Well, it's been a few months since my last entry, and I thought I should update my blog! I recently had the opportunity to see some Agraulis vanillae (Gulf Fritillary) in Florida, USA. These butterflies were quite abundant, and you can find them in urban centers as well as forested areas, wherever they have access to their larval host plants. This butterfly is widely distributed all the way to South America, and you can even find them in Hawai'i. So not unexpectedly, there are many subspecies. The subspecies found in Florida is nigrior.

The larvae of this species feed on plants in the Passifloraceae family, which includes the passion vines. There are many kinds of passion vine, both natural species and human made hybrids. Passion fruit, in fact, is produced by the passion vine known as Passiflora edulis. In Florida, I located eggs on an ornamental hybrid called 'Incense'. This is a cross between Passiflora incarnata and Passiflora cinnicata.

The above picture shows two eggs, one on each leave; they are the two little yellow dots. This was actually not taken in Florida, but on a previous trip to Hawai'i. These were eggs found on Passiflora edulis, the species that produces the commercially available passion fruit. 

Within 3 days, both eggs hatched into tiny tiny caterpillars. They are about 2 mm long at this point and are a reddish brown. You can't really see too much detail at this point. They have a black dot for a head capsule, and if you look really hard, you can barely make out little hairs on them.

As all caterpillars do, they start eating as much as they can, as soon as they can! The caterpillar is still in the first instar, but is visibly larger. You can see that it has devoured quite a bit of leaf material for its size. I personally find these chew marks adorable. Sometimes in the wild when I'm searching for butterflies, I don't come across eggs or caterpillars, but I will come across these characteristic chew marks on the leaves of their host plants, and then I know that even if I don't see them, they are around. In such cases, all you have to do is be patient and keep searching, and eventually you'll find something.

This is a second instar caterpillar, probably close to 1 cm in length now. You no longer have to squint to see some degree of detail. The hairs on their bodies are now little black spines. However, they aren't really that sharp. You can easily pick up full grown caterpillars and the spines don't get in the way at all. 

This is a third instar larva, and from this point on, as the larva grows and molts, it doesn't really change much anymore. It becomes larger, but the color pattern stays pretty much the same.

This is a fourth instar larva, still getting bigger. At this point, their poop is getting large enough that you can actually hear them dropping. When I raise butterflies, I typically keep them on the nightstand beside my bed. At night, if the caterpillars are sufficiently large, you can sometimes hear them chewing on leaves, and quite often, you can hear when they poop as well. The caterpillars in this case are on potted passion vines, and when they poop, sometimes the pellets fall on to soil, but sometimes the pellets fall on the nightstand and I hear a little "click." It's a comforting sound - I know they are eating and happy.

I stepped out of the room for just a few minutes and missed the moult! By the time I got back, it was completely out of its old skin, so I could only take a picture of this freshly moulted fifth instar caterpillar. The shed skin is that blackish crumpled up stuff just to the right of the caterpillar. After each moult, the caterpillar will usually eat the shed skin to recycle the nutrients.

This is a fully grown fifth instar larva.

Unlike some other butterfly species that crawls off its host plant and travels some distance to find a pupation site, this species will quite often pupate near or on the host plant itself. It spins a silk pad and attaches its last pair of prolegs and then hangs upside down, similar to a Monarch butterfly.

After about 14-15 hours, it will pupate.

The pupa is a mottled brown color, with irregular bumps here and there which help break up its outline. It's attempting to mimic a dried up leaf basically. After 8 days, both pupae produced adult butterflies, and both turned out to be female.

Unfortunately, both emergence events occurred in my absence, but I do remember being quite excited to see these adult butterflies. While in Florida, I also found two eggs of Papilio palamedes (Palamedes Swallowtail) on Persea palustris (Swamp Bay), but unfortunately both eggs were parasitized and they didn't make it. That was a bit sad. Maybe one day I'll encounter more of them. The third species for which I found eggs in Florida was Battus polydamas lucayus (Polydamas Swallowtail). I will be sure to write about them in another post shortly!

Papilio xuthus continued 2

I'm glad to say that all 3 pupa made it, and 1 male and 2 females emerged. I have kept them as voucher specimens.

From top to bottom are pictures of the dorsal male, dorsal female, ventral male, and ventral female. In general, females are slightly larger than males and have more orange and blue on the hind wings. The yellow wing markings in females are also a bit larger and a more intense yellow. The male wing markings are near white, especially when taken with a camera with flash.

When I raise butterflies, I keep fairly detailed notes on their life cycle, and I keep a few voucher specimens for documentation. Typically this would include 2 pairs of males and 2 pairs of females. If I raise more than that, the rest are set free as adults or late instar larvae. Pinning and setting specimens is a very detailed and time consuming process for me, as I am rather perfectionist. I may write a blog entry detailing the process some time in the future. Typically it takes me 1-2 hours to prepare a single specimen, and it takes about another week for the specimen to dry. I then store them in a box with a tight fitting lid, away from light, which over time will cause the colors to fade. I do plan to donate my collection to a museum when I die (unless I have children to carry on my work), and my specimens are never for display or sale.

Well, that's it for Papilio xuthus. Stayed tuned for more!

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.