We have entered the micro-season of “Leaf Insects Turn into Butterflies”. This is the last micro-season of the mini season of Awakening of Insects. Each mini season contains three micro-seasons. The micro-seasons contained within the season of Awakening of Insects are:
- Hibernating Creatures Open Their Doors (Mar 5 -Mar 9)
- The First Peach Blossoms (Mar 10 – Mar 14)
- Leaf insects turn into Butterflies (Mar 15 – Mar 19)
These seasons were established in 1685 by Japanese astronomer Shibukawa Shunkai and are specific to Japan. However, just because the calendar focuses on Japan doesn’t mean it isn’t applicable to others. No matter where you live you can use these seasons as a starting point for your personal exploration into the world around you.
The Cabbage White Butterfly
This micro-season coincides with the appearance of Japan’s first butterfly of spring: the Cabbage White butterfly (Pieris rapae).(1) The cabbage white butterfly is a small to medium-sized butterfly with white wings that have small black dots. These butterflies are also known as Small White in Europe and the White Butterfly in New Zealand.(2)
Vegetable farmers often identify the cabbage white butterfly as a pest. Their caterpillars can be found on broccoli, cauliflower, turnips, mustard leaves, and other plants in the cabbage family. If a commercial shipment of greens is found to contain cabbage white caterpillars, the whole shipment must be discarded.(3)
The Life Cycle of The Cabbage White
Cabbage white butterflies spend their winters attached to a host plant in the pupal stage. The Pupal stage is the last stage before the adult butterfly emerges. During this stage, the butterfly resides inside its protective chrysalis. While in the chrysalis, the pupal completely transforms from a caterpillar to an adult butterfly.(3) Shortly after the cabbage white butterfly emerges, it lays more eggs on the underside of other host plants. During the summer, it takes between 3 to 6 weeks for the butterfly to move through all stages of its life: egg, caterpillar, pupa/chrysalis, and adult. The adult butterfly can live up to 3 weeks. Cabbage white butterflies can have up to 5 life cycles per year, depending on your location.(2,3)
Other Butterfly Winter Survival Strategies
While the cabbage white butterfly survives the winter months in a chrysalis, other butterflies choose different strategies. The four basic winter survival strategies for butterflies are:
Migration and Diapause
Some adult butterflies, such as the monarch butterfly, will migrate about 3,000 miles for their winter rest. When they get down to their winter residence, they will find space behind tree bark, or cracks in the rocks, and enter diapause. Diapause is the insect version of hibernation. During this phase, the butterfly will shut down their non-essential life systems and deploy glycols to keep them from freezing.(6)
Caterpillars and Diapause
Other butterflies may overwinter in the caterpillar stage. The caterpillars will bury themselves in fallen leaves, or in the dirt, before entering diapause. They will remain in this state until their favorite host plants start to grow again and they can come out to eat.
Chrysalis
As we know, the cabbage white butterfly uses the chrysalis strategy to survive the winters. Butterflies who use this strategy stop their development during the winter and then resume again in the spring. They coordinate their emergence with the availability of their favorite nectar source.
Eggs
Some butterflies spend their winters in the egg stage. An adult butterfly will lay eggs in leaf litter at the end of the season and then hope for the best. This is probably the riskiest winter survival strategy because the eggs are delicate and a good food source for other animals.
How to Assist the Butterflies in the Winter
National Geographic reported a 1.6 percent decline in total butterfly species since 1972.(7) This is a problem because butterflies are essential pollinators who help produce many of the vegetables and flowers we enjoy. Luckily, there are simple ways that we can support butterflies to survive winter and have a good spring.
First, we can not disturb the fallen leaves that are beneath trees and around host plants. As we have seen in the winter survival strategies, caterpillars and butterfly eggs might be seeking shelter there.
Next, if you see a chrysalis around your home, leave it there and observe. A butterfly may emerge in the spring.
Finally, plant flowering plants around your homes. The butterflies will appreciate the snack when they appear.
For more information about butterfly conversation, check out butterflyconservation.org (UK) or North American Butterfly Association (US)
Resources:
- 72 Season App
- “Pieris rapae”; Wikipedia
- Pamela Opfer and Dan McGrath; “Cabbage White Butterfly”: OSU Dept. of Horticulture
- “The Butterfly Life Cycle Explained”; The American Museum of Natural History
- Jill Staake: “How Does a Butterfly Survive the Winter; BirdsandBlooms
- “Where Do Butterflies Go In Winter”: Wisconsinpollinators.com
- Liz Langley: “450 Butterfly Species Rapidly Declining Due to Warmer Autumns”; National Geographic
Looking for something else to read? The Naturalist Weekly bookstore has several curated lists of books including something for nature lovers and for poetry lovers. We even have gift cards that can be used throughout the store.
Naturalist Weekly 
Fascinating info, good sir. You don’t have to grow up on a farm to appreciate butterflies. One thing that angers me still about the previous administration was its reckless disregard of environmental habitats such as the National Butterfly Center along the Texas-Mexico border. Its insistence upon constructing a racist wall endangered much more than a butterfly sanctuary, but this place seemed to attract a lot of attention from environmentalists as a symbol of the hatred and destruction, and for good reason. It survived the previous administration, fortunately, but didn’t survive conspiracy theories from Q-Anon and was forced to close down in February of this year after incidents (and more threats) of violence. It’s a shame. When I read this essay, that’s the first thing that came to mind–how insensitive and insane human behavior can be sometimes that they’d choose hatred over butterflies… Here’s a link to the article if you’re interested: https://www.texastribune.org/2022/02/02/national-butterfly-center-conspiracy-threats/
Hi Mike, I remember hearing about this and how they had to shut down the facilities because of death threats. It is tragic that humans forget that we are not separate from the rest of the world. The human factor really is the biggest threat to all existence.