Found monarch larvae eating bindweed (Blue Vine Milkweed)

[biwa]

I know you'll think I'm crazy for saying this because monarch larva only eat milkweed, but I definitely saw some eating a vine in my yard. Monarch larva have a distinct look so cannot be mistaken.

This is the plant they were on:

[img]https://azuki.fileave.com/monarch%20on%20bindweed.jpg[/img][img]https://azuki.fileave.com/bindweed.jpg[/img]

The vine often has small 2-3 mm diameter burrs on it that stick to everything. It has big ugly seed pods in the fall. I think it had unimpressive white flowers in the spring.

[rainbowgardener]

The vine is definitely bindweed, I'm very familiar with it, pull it all the time. Don't know what the monarch caterpillar was doing on it, all the sources say they only eat milkweed.

[a0c8c]

I hate to tell you, but you're gonna wanna get rid of it if it's the only one. And gather any and all seed pods. We have that vine. It's extremely invasive, comes back every year with a vengance, and will overtake other plants. It'll climb on just about anything. Also, the roots will extend out far, and I mean far and sprout up out of no where, so you gotta dig up the whole root system. I've pulled up one in the middle of my yard that ran 15 feet to the fence where it was all over the fence. Hard to control, so I basically gave up and let it live on my fences, just no where else. As long as I keep it there, it doesn't want to spread as much.

[applestar]

Maybe what you have is Blue Vine Milkweed?
https://www.monarchwatch.org/milkweed/guide/cynan.htm
At least the Monarchs seem to think so, and I suspect *they* can ID one better than any of us!

More info here: https://www.monarchwatch.org/forums/viewtopic.php?f=7&t=225

[biwa]

Thanks for the ID applestar! I had no clue milkweed could grow in vine form like that. Blue vine milkweed... hm... the USDA database says its native to here.

I'll transplant one of them into my butterfly garden and get it a trellis. Even if its a little invasive like everyone says, if it feeds the larva of pretty butterflies, I don't want to cut it down.

[GeorgiaGirl]

Interesting; I just today saw a butterfly (not sure which type; it was lemon yellow, mostly solid with flecks of reddish brown) sipping from what I thought were wild morning glories but I am suspecting now they are blue bindweed. (I kind of like it... the flowers are gorgeous... but if they're that invasive, I guess I should kill it!)

[a0c8c]

I just found out that bindweed is a wild morning glory, so you're half right. I like them so I'm not in any hury to kill them.

[Kisal]

I just found out that bindweed is a wild morning glory, so you're half right. I like them so I'm not in any hury to kill them.

Oh, you probably will be after awhile.

Bindweed spreads like wildfire, and chokes out everything in its path. Bad news!

[biwa]

I may have used confusing terminology calling this "bindweed." I didn't realize that word meant morning glory; I thought that was just another way to say "weedy-looking vine." I agree with applestar. I think this is blue vine milkweed (which is not closely related to morning glory).

[a0c8c]

I think we're talking about two different vines. The one pictured is definatley the milkweed(the seed pods comment gave it away, we've got hundreds of seeds falling along our fences), but the one GeorgiaGirl mention with the Morning Glory flower is Bindweed. I'm assuming she has both growing, like we're stuck with.

[applestar]

Here is a photo of one pair of Blue Vine Milkweed grown from seed this spring (thanks Biwa! ) I forgot to take a picture of the other pair growing on the gate arbor, but they're about the same size over there too
[img]https://i290.photobucket.com/albums/ll272/applesbucket/Image7737.jpg[/img]

[microcollie]

https://www.fs.fed.us/monarchbutterfly/habitat/index.shtml

Interesting thing here about monarchs eating cynanchums. Apparantly not a good thing

[applestar]

Thanks, microcollie (good link, BTW)! I'm worried. Did a quick check and the plant is still being recommended at Monarchwatch. I posted a query on their forum, so I'll update with what I find out.

[applestar]

OK, what I have so far is that it's the purple flowered Cynanchum louiseae Kartesz & Gandhi formerly Cynanchum nigrum (Black Swallow-wort) that is toxic to Monarch larvae.
[img]https://www.nps.gov/plants/alien/fact/img/cylo1a.jpg[/img]
https://www.nps.gov/plants/alien/fact/cylo1.htm
It makes sense since this plant is NOT NATIVE to the Americas but is from Europe.

The NATIVE (to eastern U.S.) white flowered, heart-leaved Cynanchum laeve (Sand Vine/Blue Vine Milkweed) is OK.
[img]https://www.monarchwatch.org/grafx/milkweed/cynan.jpg[/img]
https://www.monarchwatch.org/milkweed/guide/cynan.htm

[lily51]

I don't even plant domestic morning glories, as my farmer husband had a great aversion to "bindwee". It got its name because when farm equipment is turning, this vine gets wrapped all around the parts, binding them up and bring everything to a halt.

[biwa]

Thanks for posting that photo applestar, I'm glad to see it's doing so well. Now that I've identified it, I've found tons of little blue vine milkweed plants in my lawn; I've been trying to transplant them to better spots.

The monarch larvae I saw on the blue vine milkweed last year were big and plump. Some looked big enough to start doing the metamorphosis thing. So the blue vine milkweed clearly doesn't stunt their growth.