Close Up Photo of Monarch Butterfly on Top of Flower
Close Up Photo of Monarch Butterfly on Top of Flower | Image Credit – Debadutta
Scientific Name:Danaus plexippus
Status:Endangered 
Weight:Less than 0.5 grams
Size:7-10 cm wingspan
Population:Approximately 29,000
Habitat:Open fields and pasturelands in the spring and summer, beaches and mountains in winter
Range:Travels from South and Central America to southern Canada
Diet:Flower juices, including Milkweed

Monarch butterflies are mighty and well-loved insects that serve as signifiers of persistence in metropolitan centers and usher the arrival of warmer months in remote regions. Likewise, their occurrence has a more profound significance in Mexico. In November, millions of people revert to Mexico for Dia De Los Muertos, the Day of the Dead. The tradition dictates that the monarchs are the souls of friends and family who have perished.

Generations of kids have raised monarch butterflies in primary schools, marveling at transforming patterned caterpillars into sizable orange-and-black adult butterflies. The monarch’s cross-generational migration is iconic — a 2,000-mile voyage from Mexico to Canada initiated by a group of creatures measuring less than a gram.

Appearance

Monarch Butterflies
Monarch Butterflies | Image Credit – Flickr

The monarch butterfly, which is enormous and brightly colorful, is one of North America’s most clearly recognized butterfly species. They have two wings and a wingspan of almost four inches, or seven to ten centimeters. Their wings have a rich orange color with black streaks and margins and white dots along the margins. The underparts of the wings are a soft orange color. 

Male monarch butterflies have two dark patches in the middle of their rear wings, whereas female monarch butterflies do not. Odor receptors in these places assist males in enticing female partners. Females’ wing veins are broader than males’. The torso of the butterfly is black with white patches on it.

Before metamorphosis, monarch caterpillars are banded with yellow, black, and white stripes and grow two inches long. Either terminal of their torso has a pair of antennae-like tentacles. The monarch chrysalis, a gorgeous green with tiny golden dots around its border, is where the caterpillar metamorphoses into the flying adult butterfly.

Geographical range and habitat

Butterflies thrive on the presence of asclepiad flora
Butterflies thrive in the presence of asclepiad flora | Image Credit – Flickr

The monarch butterfly is found in North and South America, the Caribbean, Australia, New Zealand, the Pacific Oceanic Islands, Mauritius, the Atlantic Canary Islands, and Western Europe. It is a frost-intolerant organism that relies heavily on asclepiad flora to expand its spectrum of breeding grounds. 

For hibernation, the monarch butterfly needs a large tree canopy, and the majority of current habitats in California are related to Eucalyptus trees, particularly the blue gum Eucalyptus globulus. These trees were brought in from Australia and have taken over the job of indigenous vegetation that has been wiped off by deforestation.

Reproduction

Orange Caterpillar
Orange Caterpillar | Image Credit – Anthony

The mating season occurs in the spring, just before the birds leave their overwintering grounds. In contrast to other species in its genera, D. plexippus mating is very straightforward and less reliant on chemical pheromones. The aerial and the ground episodes are the two separate stages of mating. The male chases, wiggles, and ultimately takes down the female during the airborne phase. Copulation occurs during the ground episode. The spermatophore is hypothesized to give the energetic female vitality resources in addition to sperm, assisting her in conception and remigration.

When the females approach their nesting sites, they lay their eggs on milkweed plant species. The egg and larval phase lasts about two weeks and is the function of temperature. At the end of this process, the larva enters a pupation span, after which an adult butterfly unfolds after 9 to 15 days.

Life Cycle

Bokeh Photography of Brown Pupa
Bokeh Photography of Brown Pupa | Image Credit – Quang Nguyen Vinh

Like other butterflies and moths, Monarch butterflies have developmental phases: egg, larva, pupa, and adult. These process modifications are also referred to as metamorphosis. The Monarch butterfly begins as a small fertilized egg strategically arranged on the bottom part of a Milkweed leaf.

The Monarch caterpillar evolves from its egg after four to five days and promptly begins to ingest the Milkweed leaves, which seem to be the caterpillar’s only source of nutrition. Although this milk in Milkweed is poisonous and unpleasant to several living creatures, the Monarch butterfly focuses primarily on these chemicals in its body to shield itself from predators. Once the caterpillar attains roughly two inches in length or 200 times its hatched size, it develops a cocoon and metamorphoses into a butterfly within two weeks.

Eastern monarch butterflies produce about three generations, or offsprings, annually in southern Canada from June to September. The duration for an egg to hatch into an adult butterfly varies based on the course of the day, the temperature, and the accessibility and quality of the food source. Ordinarily, it takes about one month. 

Monarch butterflies that emerge in the summertime migrate. They have a life span of six to nine months if they survive the winter. They do not reach sexual maturity before migrating and do not reproduce during the cold season.

Migration

Into the deep forest in mexico michoacan
Into the deep forest in Mexico Michoacan | Image Credit – Alex Guillaume

The monarch butterfly’s migration is the most finely established one compared to any documented butterfly, moth species, or existing insect. Like many other birds, bats, and whales, the Monarch butterfly relocates to less harsh climates for the wintertime. Winters are too severe in regions where butterflies breed; Monarch butterflies cannot survive extreme snowfall and a lack of vegetation for larval caterpillars to consume.

Monarch butterflies in America and Canada begin their journey to specific spots in Mexico’s highlands. Thousands congregate on a single Oyamel tree as the days become shorter and the temperatures drop. They slumber there until March, when climatic indicators cue them it’s time to go north in quest of Milkweed to implant their eggs on, as there is none at the overwintering Mexican locations. The population that performs the complete southbound migration and winter slumber will perish throughout their northward migration, and their young will proceed to the nesting sites.

The trek to the northern United States and Canada takes two to three generations to execute. Researchers are still puzzled about how the monarch butterfly understands when and how to travel such great distances to a new location.

Defense mechanism

The brilliant design of monarch butterflies makes them easy to spot, which is a problem. Monarch larvae are brilliantly colored, unlike so many other butterfly larvae, which are colored to camouflage in with their environments. The monarchs’ bright colors signal potential attackers that they are deadly and foul-tasting. Their toxicity is a result of their eating habits. Milkweed is harmful in itself, but monarch butterflies have adapted to withstand it and benefit from it by accumulating the poisons in their bodies and turning themselves hazardous to enemies like birds.

Status

Monarch butterflies, previously widely prevalent, are on the verge of rapid depletion and extinction due to overuse of pesticides, urbanization, and global climate change. Land clearing of wintering habitats in Mexico, disturbances to their movement due to climate change, the loss of native plants, especially milkweed species, and all nectar-producing natural vegetation along their migratory pathways are threats to monarch butterflies.

According to the experts, the increased frequency and intensity of extreme weather events related to accelerated rapid climate change undoubtedly contributes to the decline. The yearly March survey of monarch butterflies overwintering in Mexico’s highland, where 99 percent of the planet’s Monarchs relocate for the colder seasons, revealed that populations had dropped by 27% from the former year’s survey and over 80% since the mid-1990s.

This sharp fall was mainly ascribed to a more severe winter snowstorm in March of the previous year, killing millions of monarch butterflies. Monarch butterflies require a large population to continuously adapt to dangers such as extreme weather, pesticides, and climate change. The annual assessment of overwintering monarchs in 2020 revealed an even more drastic drop of 53% from the former year’s figure. The numbers are currently far below the point where intelligence analysts expect a surge in migration.

Conservation Efforts

Milkweed in the lawns preserves the butterflies
Milkweed in the lawns preserves the butterflies | Image Credit – Picryl

Monarch butterflies have garnered considerable attention from environmentalists since they are beloved and emblematic species. People are encouraged to grow Milkweed in their lawns and communities as a part of public awareness efforts. 

Monarch butterfly reserves safeguard the butterflies’ wintertime homes while attracting tourists who help finance their operations. Many larger-scale projects are also underway to maintain habitat, improve land management for pollinators, replace Milkweed plants, promote awareness, and acquire new scientific knowledge to comprehend monarch butterflies better.

Interesting facts

Monarch Butterfly Perching on Red Flower
Monarch Butterfly Perching on Red Flower | Image Credit – Tinthia Clemant

Slow-motion wings flap: A regular butterfly’s wings flutter about 20 times per second on average. But, the Monarch Butterfly flaps its wings 5 to 12 times every second.

Voracious eaters: Hungry Monarch caterpillars have devoured an entire milkweed leaf in less than five minutes. Milkweed is eaten at a rate of 200 times their body mass.

Gold studded chrysalises: Carotenoid hues from their milkweed meal cause the gold markings on Monarch Butterfly chrysalises.

Consuming skin shed: In reality, the monarch butterfly caterpillar is creative! It consumes the eggshell when it initially hatches from the egg. It then loses its skin five times as it develops, every time turning it into a supper.

Rapidly growing: The monarch caterpillar can expand to a weight of 2,700 times its initial size. This growth is quite astounding, given that it is only in its crawler form for 10 to 14 days.

To Conclude

According to new research, monarch butterfly wings are increasing rapidly due to climate change forcing the butterflies to migrate greater distances as their breeding sites shift north. Monarch butterfly numbers have fallen by 26% in the last year alone. These are the valuable pollinators that contribute significantly to ecosystems all over North America; hence, their extinction is a significant issue. It is not too overdue to preserve them; the concern is whether we will put forth the effort on time.

(Last Updated on May 21, 2022 by Sadrish Dabadi)

Shradha Bhatta holds a Bachelors’s Degree in Social Work along with a Post-graduate degree in Project Management from Georgian College in Canada. Shradha enjoys writing on a variety of topics and takes pleasure in discovering new ideas. She likes traveling and spending time with nature. She is a very people-person who loves talking about climate change and alerting people to go green!