Image by 272447 from Pixabay
One of the most recognized butterflies is the monarch. They are easily identifiable by their orange and black laced wings, bordered with tiny white dots. They are also well-known for their migratory habits from the United States and Canada south to Mexico for the winter.
A female butterfly will lay her eggs on the milkweed plant. They can lay anywhere between 300 to 500 eggs in a two to five-week period. They will lay smaller eggs as they age and larger females will lay larger eggs.
After only a few days, the eggs hatch into larvae, or caterpillars. The caterpillars spend most of their time then eating the leaves on the milkweed plant in order to grow. In about two weeks time, the caterpillars are ready to enter their next stage of development. They will find a flat surface and suspend themselves upside down in a “J” shape. After about 12 hours, they straighten their body out, split their skin, and reveal their green chrysalis.
They spend about eight to fifteen days in this stage then hatch out to become the beautiful orange and black butterflies we know and love. Initially they will hang upside down to allow their wings to dry. Once they are ready, they fly off to begin life on their own. If they emerge in the spring or early summer, they may then start the cycle over again right away and lay eggs on the nearest milkweed. If they are born in late summer or fall, they instinctively know it is time to migrate south for the winter.
Threats to Monarchs
The threats to the monarch species are numerous. They include breeding habitat loss, climate changes, use of pesticides, deforestation, and ozone pollution. Migrating monarchs face threats all along their journey, from their overwintering sites to their breeding grounds. Unless we change our ways, the threat could continue to grow while the monarch numbers continue to drop.
Another major threat to the existence of monarchs is a protozoan parasite called Ophryocystis elektroscirrha, or OE for short. Microscopic, dormant spores will live on the outside of infected monarchs and will number in the thousands or millions. The spores can then be scattered on the eggs that are laid or onto the leaves of the milkweed plant. Caterpillars then ingest the spores when they eat the leaves and they are replicated inside their bodies. When adult butterflies emerge, spores can be seen on their abdomens. At this point, parasites will not continue to replicate and must be eaten by larvae before they can cause new infections.
What does OE do to an infected monarch? Many things can happen. Monarchs can fail to emerge successfully from their pupa or they may partially emerge and their wings get stuck. They could also emerge with lower weight or underdeveloped wings. Females that are infected can continue to mate and pass the spores to their eggs which then continues the cycle. Monarchs that are infected also usually have s shorter life span and cannot make the yearly migration to Mexico.
So what can be done? To get OE off of milkweed, use a solution made of 10% bleach and 90% water. Completely saturate the plants with the solutions and rinse well. Allow the milkweed to dry throughout before allowing caterpillars to eat. Butterflies born with OE in their guts are obvious, usually with malformed wings or too weak to fly. The humane thing to do with these butterflies is to place them in the freezer. Immediately upon birth they are already dying a slow death – hungry but unable to eat – so this is a method to help them and also to keep the disease from being spread onto the milkweed plant.
How can you help?
1 – plant native milkweed in your yard
2 – establish a wildflower garden in your yard for pollinators
3 – avoid spraying chemical herbicides
4 – buy a butterfly kit and learn about the life cycle of the monarch while creating a safe environment for them
Tropical versus Native Milkweed
Tropical milkweed is the species that will survive in our temperate climate even when it is winter and Monarchs should be migrating. It is very important to choose native milkweed, if at all possible, to ensure that it will die out in the fall months. This will help keep the Monarch population in its migratory pattern and keep the new butterflies from continuously laying eggs in the fall/winter months. Another issue that arises is once again OE. If tropical milkweed is planted, the OE parasite will continue to flourish and continue to injure any future Monarchs. By planting native milkweed, which die back after blooming, you ensure that the parasite dies along with them, allowing each summer;’s Monarch population to feast on fresh, parasite free plants.
Tropical milkweed is more readily available and easier to grow, so what is the solution? Cut the plant back to the ground twice during the growing season in order to limit the spread of disease. You can also fully remove the plants in late summer to not interfere with the migratory patterns.
Monarch migration https://www.youtube.com/watch?v=QpffQtKN-gk