Swallowtails begin as an egg. The Anise Swallowtail (Papilio zelicaon) egg is spherical, or ball-like. They are sort of yellow or light or cream in colour. The mama oviposits (lays) the eggs one at a time on plants in the Apiaceaea or citrus family. Here is an egg that has been laid on Fennel. Other plants may include Dill, Parsley, Rue…
Temperature can often have an effect on how long it takes for a butterfly egg to hatch. Ants and other critters may take off and eat the egg. Others may lay their eggs on the egg. Who'd have thought so much could happen…and, in the meantime, something is going on inside…
You will begin to see changes in the egg colour. The top begins to darken. This will be the caterpillar's head.As soon as it hatches, the 1st instar (first larval stage) turns around and eats its own eggshell! Cool, huh.
Now, the little one will take off to look for food and its main job in the upcoming weeks is to eat and poop. Something lots of people don't realize is that in a butterfly's life, the larval time is CRITICAL.
During this time, the 'baby' gets all of its nutrition and how well it eats and how healthy it is will help to determine its adult life. Sounds kind of like humans, doesn't it? The Anise Swallowtail will undergo five instars.
As the caterpillar eats and poops, its body grows. When its skins gets 'too tight,' then its time to molt. The caterpillar will go off to find a nice quite place to do its molting (shedding of its old skin). If you are raising butterflies, this is when you LEAVE THEM ALONE. Molting often can take several hours. The old skin comes off and like with the eggshell, the larva turns around eats its skin!And then, voila! Nice and happy new larva.
Now it is time to continue with the eating…and pooping… More leaves are eaten until soon, the caterpillar is big and plump and looks about to burst from its skin.
Soon, it is time to pupate. Before they pupate, they will do a gut purge. It's like a 'binge-and-purge'…all of that last-minute eating then a nasty blast! Instead of their usual hard frass (poop), they let loose with a really loose stool (a runny poop that is like diarrhea. Eeew!).
The caterpillar is now ready to find the perfect pupating spot. It is usually NOT on the host plant but can be somewhere nearby OR even quite some distance away! Don't be too surprised to find the larva has 'disappeared' if you've left it outdoors. Although a lot of butterflies pupate with their heads down in that 'J' position, swallowtails don't. Instead, they make a silken sling or harness and their heads are positioned UP. Pupa colour can be green or brown and why the two? Who knows. Controversy exists as to this and no, it doesn't matter what is nearby (it definitely has nothing to do with camouflage!). That little blob at the bottom is the larva's head capsule-the final 'molt' when it shed its skin…After two weeks or more, a beautiful adult will eclose (emerge). (No, butterflies don't 'hatch' from a chrysalis.) Why the 'or more?' Sometimes, these beauties will go into a state of diapause. They will 'overwinter.' It means they decide they don't want to eclose just yet! So, they hang out as a pupa for weeks or months. Just give them time…
