Buddleia are host plants to the North American butterfly species listed below:

* American Snout
* Anise Swallowtail
* Black Swallowtail
* Cariable Checkerspot
* Common Buckeye
* Common Checkered-Skipper
* Eastern Comma
* Eastern Tiger Swallowtail
* Echo Blue
* Giant Swallowtail
* Great Spangled Fritillary
* Monarch
* Mourning Cloak
* Painted Lady
* Peacock
* Pearl Crescent
* Pipevine Swallowtail
* Polydamus Swallowtail
* Red Admiral (prefer white blossoms)
* Spicebush Swallowtail
* Tortoiseshell
* Two-tailed Tiger Swallowtail
* Western Checkerspot
* Western Tiger Swallowtail
* Zebra Swallowtail

Here is a link that might be useful: Buddleia article at plants delights

You may have more than one kind of 'friend' eating there, the sharper, more angular notches look almost like weevil, the more rounded 'chews' likely some kind of caterpillar/larvae. You can always go out after dark with a flashlight to identify, come back and tell us what you've found. Then we could know if something you may want to treat, or a 'butterfly' you may wish to protect.

Putting any kind of chemicals on any plant used by butterflies is irresponsible and cruel. Please don't do that. Just don't attract them if you can't stand imperfect plants.

morz8: I'll check after dark. I do know we have a lot of earwigs around the house. Think they're a likely culprit?

This post was edited by andyashton on Sat, Jul 13, 13 at 13:25

When I first saw the images, I thought immediately of weevils, too. You could also be visited by grasshoppers, beetles, and yes to earwigs.

According to an expert I heard speak one time (can't remember the name), there are no native butterflies that use Buddleja as a larval host plant. As a nectar source, it's very attractive to lots of pollinators. So, caterpillars (at least) aren't part of the problem.

Does damage of this extent occur every year? If so, you might consider removing it. It might even be on the list of invasive species in your state. If this is the first time you've noticed a problem, there are ways to protect your plants from pests without endangering the pollinators.

But as was said, we've gotta know who the culprits are.

I just went out an saw mostly earwigs and Japanese beetles all over the bushes that are being the most skeletonized. Must have caught it at the right time.

I'm interested in ways to help control these that won't be overly harmful to other species that would use this type of bush. I've heard diatomaceous earth can be useful for earwigs, and we certainly have an infestation in and around our house. But that can harm anything that crawls on the ground with a carapace, correct? And Japanese beetles fly, so that won't help. Any suggestions?

Rhizo_1: The plants have only been there 2-3 years, and damage occurred last year and again this year. If I don't find a safe and effective way of managing it, I may consider removing the one species that is especially bad.

This post was edited by andyashton on Sat, Jul 13, 13 at 21:37

Try Milky Spore treatment in your lawn to kill Japanese Beetle grubs. Hand collecting adult beetles into a cup of soapy water helps too, somewhat.
Correction as to Buddhlea being a host plant to all butterflies listed above.
Host plants are plants that caterpillars eat. Buddhlea provides nectar for all adult species listed earlier in this thread, but does not host them.

I questioned that list also, Leafhead, Rhizo. The link below the list is the source.

The full paragraph above the list says, "The sweetly scented Buddleia flowers attract many types of butterflies and at times, the flowers will be covered with hundreds of them. Buddleia act as both nectaring and food plants to many butterflies, including some that normally feed on other plants. Buddleia are host plants to the North American butterfly species listed below:"