Development and Life Cycle

One of the most remarkable aspects of monarch butterfly migration is its synchronization with their life cycle. Their development unfolds in four main stages:

Egg: Monarch butterflies prefer to lay their eggs on milkweed plants, where the females will lay between 300 to 500 eggs. These tiny eggs, about the size of a pencil tip, are white or off-white, oval-shaped, and will hatch in approximately 4 days.

Larva (Caterpillar): The term "larva" describes the growth stage for all insects undergoing complete metamorphosis, while "caterpillar" specifically refers to the larvae of butterflies or moths. It is crucial that eggs are laid on milkweed plants, as the larvae will begin feeding on them immediately after hatching. During this stage, the caterpillar will molt several times, shedding its skin as it grows. These intervals between molting sessions are called instars (1-5 instars). The larval stage typically lasts 9 to 14 days in average summer conditions.

Pupa (Chrysalis): When the monarch caterpillar is ready to pupate it will spin a mat made from silk from which it hangs upside down, firmly securing it’s hooks found at the tip of it’s abdomen into the silk. In this position the caterpillar will undergo its final molt. This stage is not called a cocoon contrary to popular usage of the word. A cocoon will have a covering made from silk created by moths undergoing a similar process. A monarch will create a hanging chrysalis and will stay in this stage between 8 to 12 days.

Adult Butterfly: Upon reaching the adult stage, the monarch's primary goal is to mate and lay eggs to continue their life cycle. Mating occurs when the monarch is 3 to 8 days old and can last up to 16 hours, with the pair staying together from one afternoon until the next morning. Females lay their eggs immediately after mating, and both sexes will mate several times throughout their lifetime. Adult monarchs from the summer generation live for 2 to 5 weeks. However, those emerging in late summer and early fall must migrate to overwintering grounds in central Mexico for eastern monarchs or to California if they are western monarchs. These butterflies are a part of the new first generation also called “Super Generation”.

The Super Generation

Unlike her great-great-grandparents or her parents, who traveled from Mexico to Canada over multiple generations, Dani will make the trip in just one generation. She is the fourth generation of monarchs this year and will stay longer (about 6 months) than her family.

However, unlike her ancestors, Dani will not be able to reproduce until next spring. Similar to other monarchs from the "super generation," she will enter reproductive diapause due to decreasing temperatures, shortage of daylight, or a lack of milkweed. During this phase, her reproductive organs will remain in an immature state. So, she will spend her days drinking nectar or clustering with her fellow monarchs, as she cannot reproduce or lay eggs during this time. caused by decreasing temperatures, daylight shortage, or a lack of milkweed. This phase will act in a way that her reproductive organs remain in an immature state. So while she cannot reproduce or lay eggs, she will spend her days drinking nectar or clustering with her congeners.