The Monarch Butterflies Have Arrived

Migrating Monarchs

Written By Rome Marinelli, Naturalist at The Inn at Honey Run

You know them; you love them. Heck, you may even raise some! So you may already know…but in case you don’t…monarch butterflies have officially arrived in Ohio!

Monarch butterflies overwinter in Mexico. Then, once spring hits in Mexico, they take flight. For the monarchs that we see, they leave Mexico for states lining the Gulf Coast. It is in those areas where the next generation will take flight. Once that second-generation has successfully completed its full metamorphosis, they head north. The incoming monarch butterflies we are seeing now are the second generation. These beauties will hang around our neck of the woods until they have mated and found their one and only. That one and only isn’t a mate…it’s milkweed! Milkweed (Asclepias sp.) is the ONLY plant that can provide the essentials for the larva. Many moths and butterflies have this strict relationship with one or a few plants, which is referred to as their host plant. Once the third generation is developed, some will stay around here, but others will migrate up to southern Canada. The fourth-generation will be the ones we see leaving in the fall and making a beeline for Mexico!

Milkweed is the only plant that a mother monarch will lay her eggs on. Just like you wouldn’t feed an infant a cheeseburger, the mother monarch will only leave her offspring with the proper essentials to see it through its metamorphosis. Milkweed produces a toxic milky sap consisting of cardiac glycosides, which help the larvae to become toxic to predators. Many other wonderful insects share a love for milkweeds. I mention this to give you peace of mind in case you see other critters on any milkweed plants you may have. See, insects depend on plants, and it just goes to show how woven the world is when we can observe so many different insects needing one thing in common.

While monarchs are marvelous, it is important to try not to interfere with these critters. I know it’s exciting to raise some indoors, and some may even think it’s crucial to do so. Believe it or not, it’s better to leave these “cats” alone in the wild. Bringing 1-3 indoors for rearing can help educate and connect children to our wonderful and wild world, however. While it was once thought vital for human intervention – in the sense of indoor rearing – that is simply not the case anymore. Let me explain.

Female monarchs lay 300-500 eggs. Through natural selection, only the strong will survive. Those survivors are then able to pass on strong genetics and help future generations, thus helping populations. When mass indoor rearing occurs, we take away that natural selection and the opportunity for strong genetics to be created. In fact, mass rearing may be doing more harm than good! Instead of having tough monarchs, we end up with sickly and weak genetics.

The role humans need to play in the conservation of the monarch butterfly (and so much more of our precious wildlife) is to provide the areas capable of sustaining them – i.e. plant native plants like milkweed!

From the field,

Rome