The good thing about milkweeds is that the sap is so viscous and sticky that even specialized aphids can't get an awfully lot. Other plants can be seriously weakened and even die from a heavy aphid infestation.

If my milkweeds have only a few aphids, I'll usually be kinda lazy about it but will get after them with a spray bottle of water and my squishing fingers before it gets too bad.

When I'm looking for eggs I patrol the milkweed for bugs. They all get the big squish, except lady bugs which I move somewhere else. When I find a little colony of aphids starting I just rub them off. Aphids attract ants, which could possibly prey on the larvae. Also they do suck some juices out of the leaves and can degrade the quality of the foliage. At the same time I remove yellowing or wilted leaves or tips. Sometimes at night I patrol for slugs with a spray bottle with an ammonia solution.

Patrolling the milkweed is tedious but it does seem to help keep the foliage nice and it's no doubt safer for eggs or small cats. If I had huge patches it would be harder to monitor.

I have had bad infestations in the past on my milkweek, and they didn't seem to bother the cats at all. In fact, after the cats ate all the leaves, the aphid problems went away, even when the new leaves emerged. James