The lifecycle of butterflies are a very interesting topic for many, and is actually quite complex sometimes. I will be talking about the Monarch Butterfly, which has a couple things that are different from other butterflies. There are some stages for the Larva/Caterpillar to turn into a Butterfly. After the Larva hatches, it keeps on eating until the next stage, the Pupa/Chrysalis stage. After 10 days, a Butterfly emerges out of the Chrysalis and goes to mate so that it can reproduce.
Every single butterfly is different in the fact that each and every one uses a single kind of plant to lay its eggs on. The Monarch Butterfly has colorful wings, which are to show any possible predators that they are toxic. Milkweed plants contain a toxin, and so Monarch Butterflies lay their eggs on Milkweed so that the Larva can eat the Milkweed. Once the Larva digests the Milkweed, it does not get poisoned, but it does get poisonous.
There are multiple stages after the Larva comes out of the egg for it to start hanging in its cocoon/chrysalis. The Larva is starving once it has enough energy, and eats its way out of the egg. Then, the Larva eats the whole entire egg, and then eats the milkweed leaves to. It just keeps on feasting on the leaves. This stage is the most dangerous stage because it is possible that the milkweed toxins might affect the caterpillar. After the Larva passes this stage it is mostly safe. This stage is marked to an end when it sheds its skin for the first time. The Larva does that because it is starting to grow too big for its former skin, so it sheds it off and grows a new one.
Stage two to five are all the same, feast, then shed, then feast, then shed… After 5 times of shedding and feasting, The Larva has now grown quite large, and can even finish a whole milkweed leaf in an hour! It is now ready for its last stage.
The Pupa/Chrysalis is the next stage. It is when the larva/caterpillar goes into its “cocoon” and starts the process of turning into a butterfly. First, the Larva weaves a small yet strong string to serve as a safety belt so that they won’t fall, and then shed their skin for the last and final time. Underneath that last layer of skin is the chrysalis, which is a soft shell that later hardens. Now the Larva becomes the Pupa and stays in the chrysalis for 10 days. What is going on in there, you might ask? Well, it is pretty disgusting and cool at the same time, the Pupa releases digestive enzymes, which practically eat/disintegrate itself alive. The Pupa becomes a soup of randomness, and in time it arranges itself into the form of a butterfly. The magic thing is that it only happens in 10 days. Scientists are still trying to find out what is happening. Once everything is done, the Chrysalis becomes transparent, and the butterfly comes out of the Chrysalis.
When the Butterfly comes out, its wings are still small and wet, so it pumps nutrients and other things into its wings for them to grow big and dry. They spend around 4 hours exercising their wings until they take flight and become a master of the air. Wow, so fast! After that, they immediately go find a female/male butterfly to mate with so that new larva can be born… What an amazing transformation, changed from fat to skinny. legs to wings, muncher to sucking tube. It even changed diets!
Studies show that butterflies remember what happened when they were a caterpillar, even through that turning into soup process.