A quick Life History of the Island Marble Butterfly

A Dead Egg attached to an empty already hatched egg through a microscopic lens on a mustard plant
Caption: 2 eggs attached underneath a microscopic. The egg attached to the plant has already hatched. The second egg has a caterpillar inside but is likely deceased.

A year in the life of the island marble butterfly

Hey everyone! Let me introduce you to the amazing butterfly I’ve been working with this summer. They’re incredibly cool-looking throughout their entire life cycle,,= which spans about a year.

So, let’s dive into the fascinating world of the Island Marble Butterfly (IMB). These little beauties come to life in spring as adorable orange eggs. In our lab, we take extra care of them to ensure their survival. In the wild, their chance of making it is only about 5%, but in the lab, we boost that up to an impressive 80-90%! You see, in nature, they face threats from insects and even deer munching on their host plants, but we provide them with a safe haven.

After being brought into the lab, the IMB eggs hang out on their plant for about 10 days, and then they transform into tiny caterpillars with big appetites. These little rascals even venture onto their neighbors’ plants for a sneaky snack when we’re not looking! They spend a solid 4-5 weeks munching away on their favorite host plants, going through five stages of growth. It’s quite a show!

Once they’ve had their fill, the IMBs go on a quest to find the perfect low-hanging plant to undergo a magnificent makeover – it’s chrysalis time. Now, in the lab, we have to be extra vigilant because these clever critters have been known to escape their cages in search of their preferred plant. Talk about determination. During this stage, they enter a prolonged slumber that lasts a whopping 10-12 months. Beauty sleep at its finest!

Then, after a well-deserved rest, the IMBs emerge from their chrysalis like true adults in the spring. They may only have a brief 6-9 days to strut their stuff, but let me tell you, they make every second count! These little fireballs waste no time, flitting and fluttering around with boundless energy. Not only do they bring joy with their vibrant presence, but they also play a crucial role in pollination as they feast on the sweet nectar of stunning flowering plants.

During this whirlwind period, the IMBs embark on a mission to find their one true love, their perfect mate. They get together, do their thing, and fertilize eggs, ensuring the next generation of IMBs will continue their remarkable journey.

The butterflies are pretty vulnerable to climate change because of their relationship to their host plants. They only lay eggs during a super tight phenological stage when the flower buds of their host plants haven’t even opened yet. It’s not just about timing. The host plants also need to be available for a precise 2-3 week period in the spring that the adult butterflies are emerging from their chrysalises. That’s their prime egg-laying time, and they don’t mess around with it. The host plants need to remain deliciously palatable throughout the larval stages, which stretch into the early summer. These butterflies know what they want, and they won’t settle for anything less. Find some photos of them throughout their development below!