Nelson, that was my experience. It was clear which plant they were on first - that is the one which showed first signs of damage. They didn't hop until I doused that plant. Then, they showed up on the two closest to it. So I drenched those. Then they showed up on the one closest to those two, and reappeared on the source plant. I keep all of my plants separate places in the house. At one point, I guess I put my freshly rooted cuttings too close to the others, because I found traces of them on a couple of VdB cuttings I'd just rooted, so those got sprayed, and I took everything out to spray it.
The stuff I have been using - Bon Neem - seems to work very well. It normally doesn't interrupt terminal buds or wilt leaves. But something I have noticed is that after application, within a week, there are little rust spots everywhere those little bastards have been munching. It's a sad thing to see!
From now on, I will be spraying all incoming potted plants if they will stay in the house. I'm almost ready to set off a bug bomb at this point! At least I haven't lost any plants to them .... yet (knock on wood)
Rafed, I saw that brand at the store the other day and I was moments away from buying it. I bought a different neem-based product to try out instead. I believe I looked at the Safer brand, and it was 80%+ of some kind of petroleum product for the active ingredient. The thought of it sort of scared me.