Monarch Caterpillar climbs the stem of a Crown Milkweed
Which end is which? Yes, that's the question a predator asks. This double-ended design gives the caterpillar some protection! Check out his or her shiny black and white feet.
Metamorphosis is the series of developmental stages that insects go through to become adults. Butterflies and moths have four stages: egg, larva (caterpillar), pupa (chrysalis), and adult. It takes a Monarch Butterfly just 30 to 40 days to complete its life cycle, with warmer temperatures generally being responsible for faster development.
Monarch females lay their eggs on Milkweed, the only plant Monarch caterpillars can eat. The eggs are laid singly and generally on the undersides of leaves. The eggs are about the size of a periods at the end of a sentence and whitish in color. Three to six days later, they hatch.
The newly hatched caterpillar is so small that it can barely be seen but grows quickly, feeding on nothing but Milkweed leaves. In 9 to 14 days it's full grown, about 2" long. The caterpillar has eight pairs of stubby legs. The first three pair of legs will become the butterfly's legs. Like a snake or a crab, a Monarch caterpillar sheds its skin five times during the larval stage.
When the caterpillar is full grown it usually leaves the milkweed plant and can crawl 30 to 40 feet from the milkweed) to find a safe place to pupate. The caterpillar creates a silk-like mat, attaches its last pair of legs to it, and allows itself to drop and hangs upside down in a J-shape for approximately one day.
The caterpillar's skin is shed for the last time as it passes from the larval (caterpillar) stage to the pupa (chrysalis) stage of metamorphosis. This time there is a jade green casing (chrysalis) under the caterpillar's skin. Immediately after the skin is shed, the inch long chrysalis is soft. Looking at the pupae, you can still see the ribbed body of the caterpillar inside. Then the chrysalis hardens to a beautiful jade green. Dramatic changes occur inside. The mouth parts transform from those needed for chewing into a straw-like tongue (proboscis) which the butterfly will need to sip nectar from flowers.
Most Milkweeds contain cardiac glycosides which are stored in the bodies of both the caterpillar and adult butterfly. These poisons are distasteful and emetic to birds and other vertebrate predators. After tasting a Monarch, a predator might associate the bright warning colors of the adult or caterpillar with an unpleasant meal, and avoid Monarchs in the future.
The Monarch butterfly (Danaus plexippus) is a milkweed butterfly (subfamily Danainae), in the family Nymphalidae. It is perhaps the best known of all North American butterflies. Since the 19th century, it has been found in New Zealand, and in Australia since 1871 where it is called the Wanderer. In Europe it is resident in the Canary Islands, the Azores, and Madeira, and is found as an occasional migrant in Western Europe. Its wings feature an easily recognizable orange and black pattern, with a wingspan of 8.9–10.2 centimetres (3½–4 in). (The Viceroy butterfly has a similar size, color, and pattern, but can be distinguished by an extra black stripe across the hind wing.)
Female Monarchs have darker veins on their wings, and the males have a spot called the "androconium" in the center of each hind wing from which pheromones are released. Males are also slightly larger. Monarchs can be found in open areas in all regions of Florida year-round. Florida's Monarchs are unique in that they do not migrate out of the state during the winter (although they are thought to move further south when cold spells approach). In fact, Florida Monarchs are the most active and most visible here during the winter months. It is also thought that Monarchs from the Northeastern U.S. winter in Florida. It is presumed that these butterflies do not return to the north in spring, but their children do..
See my set, Lubbers, Butterflies and Bees. And Fairchild Tropical Botanic Garden.