Room 211’s new class pet! Welcome little caterpillar!

Monarch Butterfly Scientific genus and species: Danaus plexippus Kingdom: Animalia Phylum: Arthropoda Class: Insecta (insects)  Order: Lepidoptera (butterflies)  Family: Danaidae (Milkweed butterfly family)  Genus: Danaus  Species: plexippus

Complete Metamorphosis Monarch Butterflies undergo complete metamorphosis and have 4 stages of life Eggs Larva = caterpillars Pupa = chrysalis Adult = imago

Eggs are laid on the underside of a milkweed plant Very small, about the size of a period on the computer

The caterpillar is quite tiny when it comes out of the egg… The caterpillar will be about 1 cm long when it leaves the egg

Larvae are milkweed eating machines! This is what our caterpillar looks like now…

Caterpillar = larva anatomy

The larva will change into a Pupa next…

A CHRYSALIS IS FORMED: The pupa is called a chrysalis rather than a cocoon. There is no silk layer inside for protection like in a typical cocoon (like moths make). Depending on temperature, the pupa will be in the chrysalis for 8-12 days.

The outside of the chrysalis is an exoskeleton, or skin, of the pupa. When it is time for the larva (caterpillar) to become a chrysalis, the caterpillar spins a silk button from which it hangs The larva (caterpillar) forms its body into a J-shape and the skin splits and falls away. Underneath the old skin is the jade green chrysalis

Diagram of the Chrysalis

This is a female inside. How do you know This is a female inside. How do you know??? See the small vertical line just below the last two black dots near the top of the chrysalis? That’s a female’s markings.

Metamorphosis in action! The chrysalis becomes more transparent...

Moving out... The front of the chrysalis splits open and a butterfly emerges = adult = imago The wings are folded when the butterfly first comes out. The process of emerging is called ECLOSION The wings have veins that fluid is pumped through which inflate the folded wings to the proper shape/size Blood was stored in the abdomen while the butterfly was still in the chrysalis

The butterfly must wait until the wings are dry before flying If the butterfly cannot hang upside down while the wings dry, the wings will not form properly and the butterfly will NOT be able to fly The Monarch must expel any extra fluid inside its body and rest a while after eclosion – process of emerging from the chrysalis (now clear not jade)

Free at last!!!

Male or Female?

The female does not have those spots The male is above. See the 2 black dots? Those are specialized scales indicating it is a male The female does not have those spots The male has two black spots and thinner wing markings as compared to the female. In the picture, the male is above and the female is below.

Female without spots

Male – see his spots?

Spots on Male Spots release PHEROMONES – chemicals that are released by one organism to try to get another organism to respond in some way Monarch Males release a special scent pheromone to attract females to mate.

More Male Facts Males are larger than females Wings appear to be narrower but larger than females Have more narrow lines on the wings than females

Female Facts Females are smaller than males Do not have spots on the wings Lay between 100 and 1000 eggs during lifetime (usually 200-400) Lay only one egg on each milkweed leaf (which hatches in about 4 days) Have thicker lines on the wings than males but the wings appear wider but yet are still smaller than males

Monarchs Taste Bad! Both the larvae (caterpillars) and the butterflies (adults) retain poisonous glycosides from their larval host plant Monarch larvae (caterpillars) eat only milkweed so they become distasteful to potential predators Monarchs are considered milkweed butterflies (like Queen and Soldier) because they only eat milkweeds (Asclepias) as larvae.

Why eating Milkweeds is good! This highly effective defense strategy shields Monarchs against almost all predators that soon learn to avoid these species after attempting to eat them.

Eating habits The eggs are only laid on milkweed Larva only eat milkweed Adults – butterflies – will eat nectar from many other different flowering plants Remember that milkweed causes Monarchs to be poisonous to predators

Milkweed – it’s all they eat as a larva (caterpillar) It’s nourishing and it allows the milkweed butterflies to taste bad to predators. Great protection!

Monarch or Viceroy? A Viceroy will look very similar to a Monarch so that predators will avoid it. The difference is that a Viceroy has an extra line across it’s lower wing area

Migration During the summer breeding season, monarchs live from 2-5 weeks during which they mate and lay the eggs that become the next generation. The last generation of the year does not become reproductive and is said to be in “reproductive diapause”. These butterflies are the ones that migrate to Mexico where they overwinter.

These butterflies become reproductive in February and March as they move north, laying eggs on milkweeds as they progress northward into the United States. Some of these butterflies can live as long as 9 months! The migratory generation has an enormous task ahead of them. Weighing less than a gram, these unique butterflies will fly between 2,000 to 3,000 miles to an overwintering location in Mexico.

Monarchs have up to four generations each summer, each one traveling a little further north than the last. The last generation of the year migrates south (usually to Mexico).

The longest flight known for a tagged adult is some 2900 km (some 1800 mi) from Ontario to Mexico. Migratory groups congregate at the same places each winter, such as Pacific Grove, California, or the mountains in central Mexico, where the trees may be completely covered with monarchs.

Final Notes: Monarchs can lose their skins up to 5 times before making a chrysalis It is important to clean the container your caterpillar is eating from for sanitary reasons (bacteria, etc.) The excrement from a caterpillar is called FRASS

Another diagram:

The end! Do you have any questions?