Death of a Monarch

Every summer, I love to watch as the monarchs fly around, laying eggs on the milkweed and seeing the tiny caterpillars chomping their way to a size ready for the miracle of metamorphosis. Last week, I found two of them, hanging in the characteristic "J" position, one on a daylily leaf and the other on a nearby zinnia.

It's exciting, watching this cycle of life. I've seen it before, in detail, even giving up sleep in order to not miss a single step. And when I get the chance to see it again, I take it. Yesterday, I noticed the chrysalides had started to turn dark, so I brought them into our house and attached them to a stick inside a punch bowl.

I've actually raised monarchs this way before, from the caterpillar to adult stage, with 100% success. I had no reason to think that these two chrysalides wouldn't have adult butterflies emerging from them when the time was right. But sometimes things go wrong. Things you never expect and didn't know could happen.

This morning, I noticed a thin, white thread hanging from the zinnia chrysalis. I thought nothing of it, thinking it was a cobweb or something. I pulled it away. Later in the day, I noticed another white thread hanging from the same chrysalis. Only something alive could be doing this, but I didn't see anything.

I went to the internet to research.

Click on image to enlarge

It didn't take long to find out that something was wrong and that this monarch would not be emerging alive. One of the monarch's natural predators is the tachinid fly. At various stages in development, the tachinid fly can lay eggs in the monarch caterpillar, or it can even lay them in the monarch when it's only a tiny egg on the leaf. The monarch continues to develop, unaware that it's been parasitized.

Tachinid fly (from Wikimedia Commons)

Undisturbed, the tachinid eventually emerges from the chrysalis just as it did with ours. I found two reddish-brown pupae on the bottom of the bowl, along with one white maggot. I crushed the pupae and the maggot, once I learned what they were. It's highly unlikely that the adult butterfly will continue to develop now.

You can see the white thread hanging from the chrysalis, as well as one of
the reddish brown pupa cases and the maggot in the bottom of the bowl.

As if that didn't make me sad enough, I noticed a clear liquid coming from a spot on the daylily chrysalis. I noticed this when I brought it in, but thought it was dew or something. I fear that the same fate awaits this chrysalis, too.

Nothing I did caused this. And there was nothing I could do to prevent it. It just drove home the dangers that these creatures face - dangers that make protecting their habitats even more important. The monarch populations have been dwindling over the years, due to natural disasters, predators, and mostly from disappearing habitat. The first two, we can do nothing about, but the third, we can.

These two monarch caterpillars on common milkweed (Asclepias syriaca)
in my garden were actually fighting and I had to separate them. There's
enough milkweed for everyone!

I do allow common milkweed to grow in my gardens to some extent. No, I don't like its appearance as a plant, and if it came up in greater quantity than it does, I would likely pull some. But when swamp milkweed (Asclepias incarnata) comes up, it stays. I purposely grow butterfly weed (Asclepias tuberosa) in both orange and yellow forms. Monarchs live and grow in my gardens and I like it that way.

I know there are other chrysalides in my gardens, even though I don't know where they are. Monarch caterpillars will sometimes crawl 30 feet away from the milkweed on which they have been feeding to a protected location to form a chrysalis. I feel lucky when I find one, let alone two.

But this is not a lucky day. I know it's all part of life, this death by predator stuff. But I don't like it and I'm sad. Not that I didn't get to see two monarchs as they begin their lives as butterflies, but because it's two fewer butterflies that will live to fly to Mexico and back again next spring. Two fewer butterflies to start the process all over again.

Each monarch will lay approximately 500 eggs over the course of their short lives. If there are five generations of monarch in a single summer and each monarch lays 500 eggs, and each one of those lays 500 eggs (and so on), you don't really have to do much math to figure out how many monarchs there won't be because the tachinid flies decided to use the monarchs to carry on their own life cycle inside them.

On the other hand, thank goodness they do lay so many eggs. Predators will do their thing, but many will survive and live out their days the way they were intended and we will be here to enjoy them.

Migrating monarchs seen in our yard earlier this week.