Monarch caterpillars are here! (and other activity on the milkweeds)

The above picture was from yesterday afternoon, so I just went out to analyze milkweed. Not many caterpillars yet, but all kinds of things love them.

Christopher, your milkweed patch is full of activities!

My milkweed has done with the blooming and seed pods are maturing. The stalks are 7-8ft tall and I need yo climb the ladder to check for monarch eggs (found some!).

Wow! I didn't know it would grow that tall. I think ours maxes out at 5' and plenty of the stalks end the year at only 3'!

Christopher Weeks wrote:Wow! I didn't know it would grow that tall. I think ours maxes out at 5' and plenty of the stalks end the year at only 3'!

That's because you experience the 'lake effect' from Lake Superior.  Much like trying to grow open-garden tomatoes on the Oregon coast, the cooling temperatures of Lake Superior will stunt the growth of milkweed and humans alike.... :-)    Only half kidding as a friend of mine who lived on the north end of Duluth along the shoreline really struggled to grow certain warm-loving plants.  His kale did great!  Yet you also are correct even as we are warmer than you but at the same latitude near Fargo....the milkweed probably peaks at around 4-5 feet and just doesn't seem to have the growing season to get taller.  Funny that my wife also announced yesterday as having seen the first monarch.  We also have a good dose of volunteer dill this year, but no swallowtail butterflies yet.  Also, the cornice at the peak of our old farmhouse roof has a vent for the attic:  The noise of all the bats going in an out of that vent is amazing as they probably raise young ones up there and start the evening festivities of insect gathering after dusk.

I just stumbled across this paper and *had* to drop a link to it here!  https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2019.00474/full

Monarch eggs and larvae were 2.5–4 times more abundant in gardens having milkweeds evenly spaced in a 1 m corridor around the perimeter, surrounding the nectar plants and grasses, than in gardens in which milkweeds were surrounded by or intermixed with the other plants.

I don't personally have a milkweed garden -- I just allow milkweed anywhere I don't need something else. Where milkweed is thick, I mow a path through it, but no more. If milkweed grows right next to a cultivated vegetable, I'll pull it, but on the edge of a veggie bed, I'll leave it. But for anyone growing it on purpose for monarchs, this might be useful.

that's some good information Christopher...thanks for posting.

I learned my lesson with common milkweed though and plan to keep it contained by mowing and pulling strays a good distance from the cultivated gardens as it runs long distances.

I had planted one at the edge of our big garden and after realizing my mistake and cutting it down I've spent the summer pulling dozens of sprouts, some as far as 6 or more feet from the original plant.

I like the idea of a mixed milkweed boarder though and need to work more on all the other milkweeds especially butterfly weeds.

My personal observation is that butterflies that depend on specific host plants will choose healthy plants to lay eggs on. It's different from pest insects that feed on sick ones with compromised metabolism.  If there are more milkweeds growing nearby, the caterpillars have a choice and pick the more nutritious one.  If it is a single plant and later gets infested with aphids, the caterpillar will have difficulty relocating. This year after I amended my soil, I saw zebra swallowtails on pawpaw for the first time. Maybe it's coincidental, but it makes sense and I am really encouraged.

I found five caterpillars on the milkweed. They will be the super generation to head south and over winter. We are in drought so I water the plant to keep it as healthy as possible. Last month there was a caterpillar feeding on a different plant that got an aphid outbreak. The caterpillar was way smaller in size and failed to morph. Fungal fruiting bodies grew out of the dead body.

Though I've never seen them doing this for myself, I've read some papers recently describing several species of fireflies that forage on common milkweed flowers as adults!!  Apparently they are eating the milky sap as well and this makes them unattractive to predators, much like the monarchs.  So there is another benefit of having milkweed around and it is providing sustenance for another iconic, beautiful, and endangered insect!