A Monarch Butterfly on pink coneflowers in my backyard garden in northeast Iowa.
(source from: EnchantedLearning.com)
The Monarch is a common poisonous butterfly that eats poisonous milkweed in its larval stage and lays its eggs on the milkweed plant. Monarchs have a wingspan of 3 3/8 – 4 7/8 inches (8.6 – 12.4 cm).
Butterflies are beautiful, flying insects with large scaly wings. Like all insects, they have six jointed legs, 3 body parts, a pair of antennae, compound eyes, and an exoskeleton. The three body parts are the head, thorax (the chest), and abdomen (the tail end). The four wings and the six legs of the butterfly are attached to the thorax. The thorax contains the muscles that make the legs and wings move.
. Egg: Spherical, ridged and white.
Caterpillar: The larva is banded with white/cream, black, and yellow stripes. It has three pairs of thoracic legs and five pairs of prolegs (which will disappear during the pupal stage). It has 2 pairs of sensory tentacles, one pair on the head and another pair near the end of the abdomen.
Pupa: The monarch remains in its pupa for about 10 to 14 days. The green cylindrical pupa becomes transparent a day before the adult emerges.
Adult: Bright orange with black wing veins and outer margins. The wings have white spots on outer margins, and three orange patches are found near the top of the forewings. The hindwings are very rounded, and they are lighter in color than the forewings. The body is black with white spots.
HOW TO TELL A MALE FROM A FEMALE
Male monarchs have a dark spot (scent scales) on the hindwing and have small claspers at the end of the abdomen. Females have thicker wing veins.
LIFE CYCLE OF A MONARCH BUTTERFLY
Butterflies and moths undergo complete metamorphosis in which they go through four different life stages. It takes about a month for the egg to mature into an adult.
Egg – The Monarch starts its life as a ridged, spherical egg only l/8th of an inch long. The eggs are always laid singly, on the underside of milkweed leaves. The female attaches the egg to the leaf with a quick-drying glue which she secretes along with the egg. The egg hatches in about 3 to 5 days. A tiny wormlike larva emerges.
Larva – The larva (caterpillar) hatches from its egg and eats it. Then it eats milkweed leaves almost constantly. The caterpillar molts (loses its old skin) four times as it grows; after each molt it eats its old skin. When the larva is about 2 inches (5 cm) long, it will stop eating and find a place (like a protected branch) on which to pupate.
Pupa – The caterpillar turns into a pupa (chrysalis). The caterpillar spins silk from its spinneret and attaches its hind end to a branch with the silk and small hooks in the anal prolegs. it hangs head down and molts for the last time. When the newly-exposed skin dries and hardens, it takes the form of a jade green chrysalis. During this stage the caterpillar turns into a butterfly as its entire body is reorganized. In about 10-12 days the chrysalis becomes transparent and a damp butterfly soon emerges.
Adult – A beautiful but damp adult emerges from the chrysalis. It pumps liquid into the wing veins to inflate them. They soon dry, but during this process, the butterfly is extremely vulnerable to predators. There is no growth during the adult stage. It can only eat liquids, which it does through its proboscis. This adult will continue the cycle by reproducing.
Female Monarchs lay their ridged, spherical eggs singly on the underside of milkweed leaves. When the egg hatches into a caterpillar, its meals (the leaves of the milkweed plant) are easily available.
The caterpillar’s first meal is its own eggshell. After that, Monarch caterpillars eat the poisonous milkweed leaves to incorporate the milkweed toxins into their bodies in order to poison their predators. Milkweed (genus Asclepius) is a common plant that contains toxins. There are more than 100 species of this perennial herb, containing varying concentrations of toxic chemicals (glycosides). The Monarch is considered a beneficial insect because its caterpillar eats the noxious milkweed plant which invades some farms
Monarch butterflies, like all butterflies, can only sip liquid food using a tube-like proboscis, which is a long, flexible “tongue.” This proboscis uncoils to sip food, and coils up again into a spiral when not in use. Monarchs drink nectar from many flowers, including milkweed, dogbane, red clover, thistle, lantana, lilac, goldenrod, etc.
PROTECTION FROM PREDATORS
The Monarch is a poisonous butterfly. Animals that eat a Monarch get very sick and vomit (but generally do not die). These animals remember that this brightly-colored butterfly made them very sick and will avoid all Monarchs in the future.
The monarch gets its poison (cardenolide glycosides) when it is a caterpillar, from eating the poisonous milkweed plant (genus Asclepias) while in its larval (caterpillar) stage.
The poisonous Monarch is mimicked by the non-poisonous North American Viceroy butterfly (Limenitis archippus), which has a similar shape, coloration and patterns. Predators who have learned to avoid the Monarch will also avoid the similar-looking Viceroy.
Monarchs are found all around the world in sub-tropical to tropical areas. They are found in open habitats including meadows, fields, marshes, and cleared roadsides.
Monarchs live through most of the USA, in southern Canada, Central America, most of South America, some Mediterranean countries, the Canary Islands, Australia, Hawaii, Indonesia, and many other Pacific Islands.
Some groups of Monarchs migrate for over 2,000 miles during August-October, flying from Canada and the USA to overwinter in coastal southern California to the transvolcanic mountains of central Mexico; this was determined by the Canadian scientist Dr. Fred A. Urquhart in 1975. Females lay their eggs along the migratory route. This migration takes up to three generations of Monarchs to complete.
Other Monarchs stay in one area their entire lives.
It takes about a month for the adult to develop (from egg to pupa to adult).
The life span of the adult Monarch varies, depending on the season in which it emerged from the pupa and whether or not it belongs to a migratory group of Monarchs. Adults that emerged in early summer have the shortest life spans and live for about two to five weeks. Those that emerged in late summer survive over the winter months. The migratory Monarchs, which emerge from the pupa in late summer and then migrate south, live a much longer life, about 8-9 months.
Order: Lepidoptera (butterflies and moths)
Family: Nymphalidae (over 5,000 species of butterflies with dwarfed front legs)
Subfamily: Danaidae (milkweed butterflies)
Genus and species: Danaus plexippus