As a disclaimer, I can and am willing to be corrected for any miss identification of any insect mentioned in the proceeding observations.
In general, I am not bothered too much by insects on our property. We have the occasional problem with aphids (ant's farming) on the potted Sempervivums and Sedums, Mockorange and Burning Bush. Sometimes the ants decide that a pot of perennials would make a good home. It's nothing a little soap won't take care of.
Last year we pulled out a Snowball bush because I had enough. It had leaf roller which caused the leaves at the tip of the branches to roll up and the leaves became skeletonized (not leaf roller). It looked so bad for so many years, it had to go. This year the High Bush Cranberry is being attacked. Viburnum Leaf Beetle is skeletonizing the shrub.
Both the larva and the adult feed on the leaves. These are not the insects you want in the garden. I don't like to spray and I feel that if something can't survive on its own it is gone. I really don't want to give up on my Cranberry yet. Control (organically) is by removing debris and searching for egg cases and pruning in the spring. That sound like too much work. To add insult to injury, these little guys are going to go into the ground and reemerge as adults who will continue to eat at the Cranberry.
I have fixed my cabbage worm problem on the broccoli and cabbage by getting some curtain sheers at Louis (our Frenchys) and covering a frame. So far that has been working very well.
The pussy toes (Antennaria) had a caterpillar cocooned around its leaves. It is very interesting in the garden but most customers don't want to see them on the leaves in the pots for sale.
Most of them were quite small but I found this one on the edge. I think it is the American Lady Lava. And I had seen them earlier in the spring in the garden.
The Scotch Thistle always gets this webbing with a caterpillar inside chewing on the leaves and leaving little deposits. I guess it depends on your point of view as to whether it is attractive or not. But what is the point of a butterfly garden if there is not a bit of damage. The larva need to eat.
We are quite sure it is the Painted Lady.
I have read suggest that it is the Painted Lady, and they really like the grey leaved plants.
I have the book 'Caterpillars of Eastern North America' David L. Wagner, although it is a great looking book, the pictures and description are great, it really doesn't have a good Key for figuring out the moth or butterfly larva. I have had more success surfing the web.
The Monarchs showed up last Friday, two of them. They are still flying around. When we first built our house back in 1991, within a few years, on my Butterfly Weed (Asclepia incarnata) we had Monarch larva. The last time was about 5-6 years ago and they were on both on the potted plants and the plants in the garden. Last year I did see one down in the woodlot, the butterfly, not the larva.
But this year, I have high hopes.