Vespids on my milkweed?

I let the milkweed grow all season for monarchs, but now I need to mow a path through it. The problem is that there's a ton of stinging insects hanging out just crawling around on the leaves. There are at least three vespids that I'm calling: wasps, yellow jackets, and hornets -- though I don't know these critters well enough to want to defend that. Anyone know what they're up to? They seem kind of befuddled.

I googled around for ideas, but most of the sources for bugs commonly on milkweed don't include vespids:
https://extension.illinois.edu/blogs/good-growing/2021-07-30-more-monarchs-what-are-those-bugs-my-milkweed
https://hort.extension.wisc.edu/articles/common-milkweed-insects/
https://www.thoughtco.com/insects-commonly-found-on-milkweed-4115862

I found this, but it doesn't include much info:
https://www.houzz.com/discussions/5793584/wasps-on-milkweed

any chance there’s also aphids on the milkweeds? those two pictured seem to be in ‘licking something up’ position, and honeydew from aphids (or other homoptera) seems a likely reason, there on the top of the leaf.

I didn't see any kind of fluid on the leaves, but there is a sooty residue that could be junk stuck to honeydew. I'm not prepared to go lift the wasp-covered leaves to check the underside with a magnifying glass for aphid colonies. :-)

They were crawling around slowly "staring" at the leaf surface and would occasionally bump into one another and tussle a bit before going back to staring at the floor.

My butterfly weed had orange aphids this year...on every seed pod. They were the exact color of the flowers.  I kept meaning to get a picture and now they are gone.  Just went to look and I don't see any wasps/vespids there of any sort although we've had all that you mentioned on a rotted fruit pile I made for butterflies.

Yours looks like common milkweed?  I have that also and there is no sign of aphids or wasps.

Interesting to try to figure the what and why to the situation but I wouldn't mow there either unless maybe on an early cool morning with a scythe?

i’ve had some startlingly pink aphids on my common milkweed during the year, is why i was thinking aphid honeydew. funny that the bugs seem to match the flower color so well. that sooty residue could be powdery mildew in Asclepias, too. seems a farther stretch that the vespids would be interested in that, though…

Looks like bald-faced hornets lapping up honeydew to me.

These hornets mob certain plants in my garden every year. I have never been bothered just working around them, but seems like any bunch of hornets could get nasty if they feel threatened by you mowing down the plants they are feasting on.