Essay, Research Paper: Monarch Butterflies Coevolution With Milkweed

Monarch Butterflies (Danaus plexippus) and Butterfly Weed (Asclepias tuberosa)
Monarch Butterflies and Butterfly Weed, a type of milkweed, have coevolved as plant and pollinator. This means that they both rely on one another to survive. Milkweed is the primary source of nutrition for monarchs. Monarchs only eat Asclepias tuberosa a particular species of Milkweed. The monarch relies on toxins in the milkweed to fend off predators such as birds. The toxic tendencies of the milkweed plants caused the government to attempt o eradicated the plant along roadsides and in cow pastures. This has caused a major decline in population of milkweed, which is also endangering monarchs. Milkweed relies on the monarch to pollinate it so that it can reproduce.
The life cycle of a monarch revolves around the Butterfly weed plant. First the monarch lays its egg on the leaf of the plant. Once the Caterpillar is born it eats the leaf for nutrition. The Monarch caterpillar is striped black and yellow. As it grows and becomes ready to become a chrysalis by forming a cocoon it uses the plant again. The caterpillar forms its cocoon on the Butterfly Weed. By the time the caterpillar is ready to become a chrysalis it has grown to be about 45 millimeters in length. The chrysalis is pale green and spotted with gold. It becomes more transparent as the butterfly gets ready to break free. The adult Monarch has a wingspan of about 4 inches. The male and female can be told apart by a gland on the wings. It is apparent as a black circle on the male, which is not present in the female. The Monarch is native to North and Central America. The plant and its pollinator have grown to depend on each other.
The Monarch has an extensive migration pattern. Every autumn thousands of monarchs in North America migrate southward over winter and begin to return in the spring. Many monarchs go as far south as Mexico. On their journey southward the monarchs lay their eggs on the milkweed plants. There are two distinct geographical locations of Monarchs in North America. The eastern and western populations, one of which is highly endangered. The eastern population breeds east of the Rocky Mountains and migrates to Mexico. This is the group that is native to Texas. The western group which breeds west of the Rocky Mountains and migrates to the California.
The Butterfly weed is the plant dependent on the Monarch butterfly. It is native to North America and can be found in the Kinkaid backyard. The plant is a stout rough haired perenial with long roots. It is leafy and bears numerous clusters of bright orange flowers. This plant is unlike other milkweed plants because it has a scanty milky juice. The Butterfly weed is a member of the Asclepiad family of plants. Some members of this plant family are toxic. This makes the plants dangerous to cattle. Written by Cyrus Aghili. The governments of the united states and Canada have attempted to eliminate them from roadside areas which has caused a great decline in the plants population.
The Butterfly weed relies on the monarch to pollinate it. The monarch spreads the pollen from one milkweed plant to another. This ensures that more milkweed will be produced. In turn the milkweed provides nutrition for the monarch and it gives them a place to lay their eggs. This is the co-evolution of plant and pollinator.