There is a milkweed beetle that will eat a milkweed plant like that. It looks like a giant lady bug. I unintentionally introduced them into my garden one year on a tray of purchased milkweed seedlings. At first, I thought they were just very big lady bugs until I began to see the damage on the milkweed and began looking for the culprit. They are good at hiding under leaves, in litter or mulch on the ground and they are fast; will drop immediately to the soil when they feel threatened. It took me two years to pretty much get rid of them. This beetle will eat your milkweed if left to their own devices.

I can't tell by your photo how big the plant stem is but if it is a small milkweed, they can do that kind of damage very quickly. However, you mention damage on other plants, too. I'm not certain but I 'think' this beetle only consumes milkweed.

Sorry but this is the only photo I have of adult(s) When inmature, their back is a putty gray or dirty white color and even at that stage, can do a lot damage.

Hi Mary,

Thanks....I haven't seed any beetles/bugs like that around, but I will be on the lookout. Do they feed at night or during the day? Seem like the culprit eating down my milkweed seedlings/cuttings do so through the night :(

That milkweed in picture was a 5" cutting that had rooted a while back and was full of leaves.

Happy Gardening, Jeannie :)

I just went out and noticed more of the milkweed seedlings chewed up, but no Monarch cats to be find in that area.

These are the other plants chewed up new the milkweed rooted cuttings/seedlings....

Mary's picture is the swamp milkweed beetle AKA Labidomera clivicollis. They show up in northern Mexico so I figure they are also in TX. I get them but always in small numbers and sometimes absent for a year.

Check at night to make sure noctuid moth caterpillars are not chewing on your plants. They, like slugs, will travel some distance.