A Year-old Mystery Solved!

Exactly one year ago, I set off along this very shore of the Hudson River at Moreau.  I was searching for one of our native orchids, called Shining Ladies' Tresses (Spiranthes lucida), that I'd found blooming on this date along this same bank in other years.

So that bank was where I was moseying along, close to shore under the overhanging trees, when I saw this odd collection of tiny green jelly-like orbs cohering into floating shapes like hunks of miniature corn cob or six-parted posies. 

What the heck WAS this stuff?!  I had seen floating green jelly-like orbs of a cyanobacterium called Nostoc balls before, but they didn't stick together like this, nor do they show up until the fall.  Also, I could pick Nostoc balls up and the gray-green opaque orbs kept their perfectly round shape in my hand. As soon as I touched these shapes, they disintegrated into amorphous slime.  The  only way I could bring them closer to examine them was to hold water in my hand.  Then I could see that each "posy" was made up of tinier transparent orbs. I had never seen anything quite like this in my life.

 So back in June of 2022, I posted the above photos on Facebook, asking any of my naturalist friends if they knew what these green blobs were.  Nobody ventured a guess, back then.  But then, THIS year, on the same date, Facebook Memories posted the same photos again, along with my query.  I shared that Memory again, and this year, I got an answer!  At first I found that answer hard to believe.  A fellow naturalist named Mike Adamovic wrote: "They look like Spongy Moth caterpillar droppings."

Say what!?  SPONGY Moth frass? (I'd been showered with Spongy Moss caterpillar poop last year, and I did not recall it looking like this.)  "Yep," Mike replied, adding, "You can even see the leaf fragments they were chewing on floating on the water."  I looked at my photo again, and he was right about the leaf fragments.

Still skeptical, I searched Google Images for photos of Spongy Moth frass.  Most images looked nothing like my photo.  But then I saw this one:

Aw gee, except for these being brown and dry, this Google Image of Spongy Moth frass looked exactly like the shapes I'd found floating in the river.  And who knows what this dry brown poop would look like after soaking in river water? Also, the accompanying leaf fragments in my photo indicate that MY caterpillar poop was probably very fresh.

How amazing! What a complex digestive tract this caterpillar must have, to extrude this complicated shape of poop!

Thanks Mike Adamovic, for providing the answer to this year-old mystery.  And thanks, Facebook Memories, as well, for posting this photo once more, just when the right expert was seeing my post.  This is exactly what Facebook can be great for.

Oh, by the way:  I did find the Shining Lady's Tresses, right where I hoped I would find it. This is our earliest Spiranthes species to bloom, and easily identified by the noticeable yellow lower lip.