Spittlebug eggs are laid in late summer and are left to over winter on plant debris. The eggs will hatch in early spring and go through five Instars, or stages, before becoming adults. When the nymphs originally hatch in early spring, they will attach themselves to a plant and begin feeding. They are a wingless, green creature at this point and are almost invisible inside the spittle. [about.com]I had tried just hitting the spittle with a blast of water from my spray bottle,
but they just came back a day or two later. So today I took a closer look and spotted the little light green nymphs after blasting away their protective foam. Then I was able to hand pick them.
Now I need to find some spiders to feed them to. Maybe they'll develop a taste for froghoppers and help me out.
Found a neat little summary complete with an example on a rosemary plant at the UC Davis IPM site.