Although Japanese and June Beetles are members of the same family, Scarabaeidae, no one should think of them as also known as, aka, because they are not. Those larva are members of that Scarabaeidae family of beetles of which there are some 30,000 different beetles. The larva feed on organic matter in soil during some growth stages and if population numbers are high they can be quite destructive while others are, Japanese Beetles, are more destructive as adults. The best time to apply controls, if necessary, is just before the eggs hatch in late July to August, when the larva are most susceptible. Those that overwinter pupate in the spring and emerge as adults to begin the cycle again in late May thru June, but they do not ingest any food then. What to use for control depends on which of these beetles you have. There are biological controls, Milky Spore Disease (Paenibacillus papillae) for the Japanese Beetle larva, parasitic nematodes for all of the larva, and some quite harmful other poisons available. Talk with the people at your counties office of your state universities Cooperative Extension Service about the best control strategies for your area.

I put a pot with a cutting I took in Spring from the swamp rose mallow right next to it while I try to figure out what weeds I have (or other plants in that family) If they do go for it, great. I will still have learned what I have in my yard. Hope this is really rose swamp mallow. The mother plant popped up about 10 years ago in my brush pile. Since it is by now in deep shade and still flowering nicely, I thought I will take some cuttings. This is a look at the poor aquarium plant and the hopefully new food source.

https://duckduckgo.com/?q=Milkweed+Tussock+Moth&t=ffcm&ia=images&iax=images

Since I don't know what hardly anything is, I like to try out "Seek", my phone app, which thinks it is a "Western Tussock Moth". https://www.whatsthatbug.com/2011/05/02/western-tussock-moth-caterpillar-2/ "Be sure to keep your distance. Blood from this species will burn you. They will leave blisters and boils on the skin as a defense mechanism designed to repel birds." (At least that's what a commenter says)