What is this???

[Moroshka]

Hello fellow gardeners! If somebody can help me with figuring out what pest is depicted on the picture from my garden. I thought it was some kind of insect droppings but when I brought one weed inside to take a picture all those things started moving! I about had a heart attack! First, they were on the fence then on some weeds near the fence, now on the new blackberry plants near the fence. Please help me to find out what those nasty things are and how to get rid of them! Thank you in advance!!!!

[HoneyBerry]

They might be potter wasp coccoons. They sound like they are still alive inside the coccoons.
Are the coccoons about the size of a marble?
I can't say for sure if they are potter wasp coccoons, but they might be.

[ButterflyLady29]

Your location information would help. Not all areas have the same critters.

Do those blobs stretch out into worm like caterpillars? Or are they hard with living things under them?

They look a bit like sawfly larvae, but those are caterpillars. They do curl up into little balls during the hot part of the day.

[Moroshka]

I am in Central Utah. They are a little soft to the touch, a bit like a gummy bear (no offence to gummy bears) but they look like mud. There is a green caterpillar inside. I actually contacted a pest diagnostics lab today. They replied and said that it is some kind of leaf miner but they don't know which kind for sure. They said that it usually stays on the "host plant" but I can tell you that it most definitely "jumps" to other plants as well. I'm just trying to find out if I could do something to get rid of them other than hand pick them one by one of my good plants. Thank you so much for trying to help me solve this problem.

[HoneyBerry]

Here is a close up of potter wasp cocoons (not my photo):

If it is potter wasps, they will leave on their own once they have hatched. They do not reuse the cocoons.

Sometimes I get a different type of wasp. I just leave them alone. Wasps look creepy but they aren't aggressive like yellow jackets can sometimes be. They are an important part of the ecosystem.