Many of us are familiar with the decline of the monarch butterfly population in North America. But, did you know that there is actually a sister species of monarchs thriving in South America? And even more exciting; the migration and habits of this Danaus plexippus subspecies still remains mysterious to both scientists and butterfly observers alike.
After settling in Argentina a few years ago, I was surprised and pleased to see a group of monarch butterflies basking on a shrub one morning. They seem to be very young butterflies, probably fresh from their chrysalis as they were fanning their wings in the sun.
The monarchs of North America have been thoroughly studied, their migrations monitored and their habits tracked for decades. Their South American counterparts however, still retain an air of mystery. Entomologists know that they over winter in the tropics of Northern Argentina and surrounding landscapes - think Iguassu falls. The exact route of their summer migration, however, is still unknown.
After a few years of observation I can attest that they come through this area twice a year, during spring and once again through fall. During both seasons I see old and young monarchs during about a months' time. This leads me to suspect that mature monarchs fly in, lay eggs that eventually become caterpillars then butterflies, who take on the migration to either north or south.
Another mystery is the nature of their host plant. On the land where I live I have spotted tropical milkweed, but only a few, growing wild. When doing research online their is speculation that South American monarchs have expanded their diet beyond just milkweed and may lay eggs upon and feed upon other species of plants native to this region. As of yet this has not been confirmed but I can say that I have often seen young butterflies drying their wings on the plant in the title picture called "ramillete de campo".
I will continue my observation of this beautiful butterfly as well as my attempts to germinate more diverse species of milkweed. As always I continue to cultivate many different flowers to provide them nectar in my pollinator garden.