That's just the issue I'm trying to address rhizo. I've tried doing exactly what you suggest multiple times, but I've never found a single pest despite churning up the dirt and inspecting with a flashlight at night after watering. I've even tried doing this at dusk and at midnight, and even at 3:00. I never see a single pest day or night, but my lantana is constantly eaten up each and every day (as demonstrated in the picture). Is there a common leafeater for lantana?

as rhiz said ... no treatment.. until an ID ..... period ...

come on... take up the gauntlet.. you can find them ...

besides... there is a possibility.. they are gone... and that is why you cant find them... and if that is the case... then anything you use.. is simply pollution ...

you have already seen the moths .... so those caterpillars are gone ...

as a last case chance.. snip off all the affected leaves... and see if there is further damage ...

i have no adversity to going full on chemical ... but i never use it.. unless i can find something to slaughter ...

ken

Perhaps snails?

Given that that the leaves being eaten are from all parts of the plant, including the very top where there's new growth (~2ft off the ground), I'm thinking these are caterpillars climbing up there. I've never seen any slugs or snails at all at any time of day or after it rains. The other major pests for lantana are all sap sucking for the most part, and not leaf eating (mites, mealy bugs, whiteflies, aphids, lacebugs etc)

Jottle, call your local extension office to see if there's a particular pest in your location that feeds on lantana.

I grow lantana's but I've never seen anything like the damage you show in your post.
Whenever I have a problem, like mildew, frost damage etc..., I just cut them down to the ground, and start again and cut way down on the watering. They like it dry.

Here is a link that might be useful: Lantana

Lantana is a host plant to many butterfly caterpillars:
Buckeye
Checkered white
Dogface
Gulf fritillary
Julia
Pipevine swallowtail
Red-banded hairstreak
Variegated fritillary
White M hairstreak
White peacock
Zebra swallowtail

Is your Lantana for a butterfly garden?

While lantana is touted as major nectar plant for all sorts of butterflies, I have never seen anything written about lantana as a host plant except for moths and one of the hairstreak butterflies. I suspect the problem is moths.

Snails and slugs are night feeders. You can put out a tuna can full of beer and they will drink it and die.

I totally forgot to update this thread! In the end, I went out in the middle of the night and found 3 well-fed caterpillars chomping away at the lantana. So it was as I had expected. I hand picked the caterpillars and moved them to a nasty's neighbor's front yard. Then I bought some thuricide to get rid of any that I didn't find that night. Things have been good since. I do hope they weren't Monarchs :( There's a ton of moths in the ivy next to my lantana. So I suspect it was all moth caterpillars.

No, it wasn't monarchs. They can only eat Asclepias plants. If you had taken a pic of them, somebody would probably recognize them. Most caterpillars are only able to eat a few kinds of plants.

I know this thread is old, but I feel I need to comment based on something posted earlier. Lantana is a NECTAR plant for most butterflies, NOT typically a HOST plant.

I too have something seriously eating away at my lantana. My plant looks just like yours, holes all over the poor plant. But there is a huge bush of lantana right across the way, and the leaves are untouched. Could it be that the one that is being eaten is in a pot, and the other one is in the ground about 4 feet up?