Monarch Madness

Monarch Butterfly enjoying Swamp Milkweed (Asclepias incarnata) earlier this summer

I've been away a lot this summer, but I am happy to report that our garden is doing just fine without me. Luckily, I put in a few days of weeding and thinning in June, or the whole place would be a mad jungle, overgrown and covered with towering goldenrod and swamp sunflowers. Instead, it is a lush and thriving riot of colors, but with some boundaries! And so when I returned this week from yet another trip out of town, I was tickled to discover about 20 monarch caterpillars happily munching on the big Swamp Milkweed (Asclepias incarnata) in the front yard. It is common to see Monarchs here all summer, but the population really picks up in September and October as the butterflies make their way, usually above the treetops, to Mexico for winter. I believe that the caterpillars I'm seeing were from eggs laid one or two weeks ago. It appears that there are two batches on the bush--the big fat ones that are just about ready to pupate, and the ones about half their size that will be grown in about a week. I saw a female laying eggs yesterday and I hope that the ravenous hordes leave a few branches for the last generation.

Monarch caterpillars, madly munching

This is important to me because I love Monarchs. They're really pretty, and who doesn't admire their amazing migration story? And they're in danger. Monarch populations have decreased by about 90 percent from numbers recorded over 20 years ago. The causes are many--habitat destruction, pesticides, herbicides, and loss of their food source--milkweed, to name a few. It's exciting and uplifting to participate in the Monarch life cycle. Our yard is certified as a Butterfly Habitat and is a stop on the Rosalynn Carter Butterfly Trail. Monarchs will only lay their eggs on plants in the Milkweed family. There are many varieties specific to regions of the country. We plant native nectar and host plants for many kinds of butterflies and refrain from using herbicides or pesticides in the garden. The result is a healthy habitat for all sorts of creatures--butterflies, bees, wasps, birds, moths, spiders, etc.

Milkweed Bugs eat Milkweed Seeds

Aphids infest the milkweed every year. They drink the sap. I don't mind them, but if they bother you, you can squirt them off with a hose or just brush off with a paint brush. Pesticides will harm other insects, such as butterflies.

Great big Green Lynx spider and lots of aphids

Japanese Lady Beetle (aka Ladybug) and aphids

Milkweed Beetle eats the leaves

But the garden is not without its perils for the butterflies. Last night I walked past the milkweed bush again and flushed a bird that was probably hunting for caterpillars and bugs on the stems. A moment later I spotted the female Monarch that earlier I had watched lay eggs. She was caught in the jaws of an enormous Green Lynx spider perched on top of the milkweed bush. The spider had caught the butterfly and was eating it. I felt a temporary twinge of sadness for the butterfly, but then cheered for the spider who needed food for herself. Her huge abdomen was swollen, probably with eggs, and she needed nourishment, too. The butterfly had passed on her genes through her eggs, so she had fulfilled her biological destiny and was now part of the food chain. Whether those eggs will grow to adults and also pass on genes is a crap shoot. But this is why butterflies lay so many eggs, and why it is important for there to be milkweed patches all over for them to lay their eggs on. This morning I found that the spider had caught one of the caterpillars and was busily sucking it dry. Birds and wasps catch and eat them, too. Aphids are very attracted to milkweed. They are sap suckers, and sometimes they will harm or kill the plants. But the aphids attract ladybugs and their larvae that snack on aphids like popcorn. Milkweed Bugs make their home in the plants and eat the seeds, and Milkweed Beetles eat leaves. The 20 hungry Monarch caterpillars will strip the leaves off the bush within another week or so and may eat themselves out of house and home. All these beings are competing for the resources on these plants.

Green Lynx spider with Monarch for dinner

Something killed this caterpillar, and now it is food for the ants. The green blobs are caterpillar poop, also called "frass"

Green Lynx Spider with Monarch caterpillar for breakfast

New Monarch egg, with shadow of a ladybug larvae on the back of the leaf

Big, fat Monarch caterpillars quickly defoliate a milkweed plant

Some people who grow butterfly gardens will collect the eggs and grow the caterpillars to adults inside protective enclosures to keep them safe. I totally understand their care and concern, but as I told someone yesterday, I am more of a "free range" butterfly gardener. It makes me uncomfortable to make these creatures my captives. I feel much better about providing an opportunity for them to grow and thrive out in the world, but as part of a greater ecosystem. That's another aspect of the tragic loss of the massive Monarch population. They are part of an interdependent web of life. We all feel their loss. I encourage everyone who has an interest in helping the Monarch to try to plant native milkweed in their garden or even in a container garden on a deck. Do your part to help keep this iconic insect from disappearing. Go out and garden on!

The caterpillar doesn't seem to mind the aphids

Update: a few days later I went out to see if the Green Lynx spider had caught any more caterpillars and found that it was missing! In its place was a caterpillar, casually chewing on the leaves of the hunter's lair. I thought the spider must have become a meal for a hungry wasp or bird, an ironic turn in the in the circle of life. But then I saw some movement in the Blue Mist Flower bush next to the milkweed. The spider had simply moved to richer hunting grounds. Maybe she got tired of eating bitter Monarchs, but in any case, the milkweed is now packed with caterpillars and other insects of all shapes and sizes, safer for now. The egg I pictured above hatched and its tiny contents now roam the branches alongside of the aphids. And I spotted the first of what I imagine are many chrysalids hanging from a low tree sprout, far away from the caterpillars and things that hunt them. And so it goes...

Caterpillar chewing on the spider's lair

Happy spider

New hatchling, not much bigger than an aphid

A fresh chrysalis, hopefully one of many