You left out one significant leaf eater - Japanese beetles. They too really like the "Zebrina" flowering mallow, so I allow some to grow on the garden borders as a trap crop. I just patrolled the garden - spray bottle in hand - and there was a beetle or two on almost every plant.
@flowerbug I hear you about the seed production & persistence. To me, that is a feature, not a bug. Believe it or not, quite a few local gardeners who saw my gardens wanted seed for Zebrina, even after I warned them about how it could spread. Personally, as "weeds" go, this one is pretty easy to deal with; better than the wild mallow it is gradually replacing. A consistent pollen source for the local bee population, pretty in the garden, a deep tap root that opens up the hard pan, and a good JB trap crop... I like to choose my weeds for their redeeming qualities.
Oh, and have you ever noticed the metamorphosis that the plants go through later in the season? The later plants have much larger leaves than those which sprout in the Spring. The flowers on those plants will be darker purple too. I've read that the leaves of all mallows are edible; and although I already have plenty of greens, I'm tempted to test the leaves of Zebrina. Some of those leaves are 5-6" across now.