KILL IT!!! As sad as that makes me to say.. These guys are brutal, if they reproduce in large numbers (and they do that fast) they can demolish entire plants in days. Now, I'm in Canada where these guys are an invasive species with no natural predator, so of course look up what to do in your area, they might not get so out of control in Colorado. They're so hard to get rid of when their population explodes so I'm always out in my garden on the hunt for them. Hopefully that's not a problem where you are and he can keep on snacking safely, but at the very least keep an eye out for them!

Super invasive Japanese beetle.

Put soapy water in a jar and put the jar under the beetle. Push it in the jar. Sometimes they jump off the leaf when they sense danger, that’s why you put the jar below them.

They love Virginia creeper, so much that you should consider getting rid of any you have.

They live in the dirt during winter, and warm winters mean more Japanese beetles. We had a cold winter, so this year isn’t as bad as last.

Japanese beetle

Ravenous little bastards. Japanese beetle, as others have noted.

Out on the western slope they got them under control by collective action. Takes a combination of nematodes and fungi for the larvae in the soil, and judicious use of traps to draw adults out of the desired area. There are plans to introduce one of its natural predators in order to control it.

Edit: CSU has a lot of helpful info here

2nd edit: A great Sun article on the topic here

As a kid I would kill these by the thousands with a long pokey rod. I would fill garbage bags with these little fuckers. Clingy as all hell too.