Monarch Butterfly

Danaus plexippus

Monarch Butterflies have an amazing life cycle, unique in the insect world.

Many people have made it their life’s work to learn more and to study about this incredible insect!

In the entire world, no butterflies migrate like these regal butterflies of eastern North America.

Individuals travel much farther than all other tropical butterflies, up to and beyond 2,000 miles.

Females can lay several hundred eggs, usually laying a single egg on a plant. The eggs hatch about four days after they are laid.

Caterpillars eat plants only in the milkweed family. There are over 100 known species of milkweeds in North America.

Adults drink nectar from many species of flowers. Nectar contains sugar, which serves as the main energy source for the butterfly.

They have an effective chemical defense to protect them from predation; when they eat milkweed, they sequester the poisonous cardiac glycosides in the milkweed. Cardiac glycosides are poisonous to vertebrates; as a result, most of these butterflies face little predation from frogs, lizards, mice, birds and other species with backbones. Their bright colors also serve as a warning to predators that they contain these poisonous chemicals.

Several species of birds—most particularly black-headed grosbeaks and black-backed orioles—can eat adult butterflies in the overwintering colonies. While grosbeaks are relatively insensitive to the cardiac glycosides, the orioles have figured out which parts of the bodies are safe to eat and avoid the most poisonous parts.

Grosbeaks and orioles can kill more than 10% of the total monarch populations in a winter.

The caterpillar stage is also known as the larval stage; the caterpillar is an eating machine, taking few breaks even for resting.

Larva molts, or sheds its skin, five times before entering the pupae stage. The entire larval state lasts from 9-14 days under normal summer temperatures.

The pupa stage is often called a chrysalis and usually lasts from 8-13 days (the lower time corresponds to warm conditions. It is not a cocoon, since it has no silken covering.

Male and female are easily distinguished:
males have a black spot on a vein on each hind
wing that is not present on the female.

Adults in summer generations live from 2-5 weeks; those that emerge in late summer and early fall can live up to 8-9 months to survive the trip to and from their overwintering sites in Mexico.

Most butterflies found east of the Rockies winter in the Transverse Neovolcanic Mountain Belt in Mexico; those found west of the Rockies winter along the California coast where they roost in Eucalyptus trees, Monterey pines and Monterey cypresses. California's population make up about 5% of the overall worldwide population.

In Nahuatl, an indigenous language of Mexico, butterflies are called 'papalotl' . From this word comes the Spanish word for kite: 'papalote'. Monarchs are known as kites of the mountains.

These butterflies are found throughout the U.S., in southern Canada, Caribbean Islands, Australia, New Zealand and other Pacific Islands.

Not all migrate. There are continuously-breeding populations throughout the New World tropics and the Caribbean that remain in the same place throughout the year.

When they migrate south, they are in a physiological state called "reproductive diapause," or arrested sexual development. These monarchs will not mate or lay eggs until their diapause ends in the late winter or early spring.

Monarchs are in the butterfly family Nymphalidae. Members of this family appear to have only 4 legs, but they really do have 6; their front pair of legs is greatly reduced in size and tucked up under their head.

While mating, they remain in copula for up to 16 hours. During that time, the male transfers nutrients to the female, along with sperm. These nutrients are used by the female in egg production.

Spiders, mites, ambush bugs, ants, lacewings, wasps and stinkbugs all eat monarch eggs or larvae.

Larvae, like other caterpillars, have very poor vision. They see through six pairs of simple eyes, called ocelli.

The long black tentacles on the larvae are not antennae. The antennae are very small and are on the bottom of the larval head.

The butterflies use "thermals," or updrafts of warm air, to allow them to glide as they migrate, thus conserving energy for their long flight. Migrating birds also use thermals.

In 1983, the IUCN Invertebrate Red Data Book designated monarch migration a threatened phenomenon.

Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect.

Romans 12:2

Monarch Migration

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