Spittle bug egg masses. I sometimes get them on S. greggii. Just hose them off.

The nymph stage of the froghopper (aka spittlebug) protects itself from predators by covering itself with the 'foam' you describe. As a youngster (which in my heart I still am) I knew the foam by the name 'cuckoo spit'. You can either either remove the foam by hand and give the nymph a terminal squeeze or hose the foam and nymph off as desertsage suggests although the creature is quite nimble and it may return. A systemic insecticide gives a long term prevention.

Jim

I've fought them for years and seen quite a bit of damage done by the nymphs as they attack the plant's xylem layer and I wouldn't suggest either hosing or a systemic. As noted, they are mobile enough to quickly return if hosed off. The problem with systemics are the damage they do to the beneficals and the hummingbirds and other wildlife that are drawn to 'May Night' and other sages.

Handpicking and K-based insecticidal soap application are my suggestions. For the insecticidal soap, a strong stream is necessary to penetrate the foam and kill the nymph.

Thank you all!

LOL at the name - spittle bug - how fitting!

I hate to use systemics for the reasons cited by dicot, so will probably try the hosing first. If that doesn't work I'll move to the insecticidal soap.

Handpicking - I'm not sure what I'm looking for but will do a google search and figure it out.

Thanks again.

Oops, all I meant by "handpicking" is using your fingers to squish the bugs. It grosses most people out, but it's how I kill most of the spittle bug nymphs.

Here's what you're looking for. This one is about 1/8" long.