What is that white foamy stuff I saw dripping off all the leaves in a forest in Northern California and then again on some of the plants around Whistler, Canada?

July 12, 2007 7:06 AM

What is that white foamy stuff I saw dripping off all the leaves in a forest in Northern California and then again on some of the plants around Whistler, Canada? My first thought was bird droppings, but it seems a little too insubstantial for that. A few people thought maybe it was sap or pollen. Does anybody know for sure?
posted by willnot to Science & Nature (9 answers total)

Best answer: cuckoo spit?
posted by crocomancer at 7:12 AM on July 12, 2007

Probably poplar fluff - heck, we just came out of a 2-week period where it was blowin' like snow.

Or - did you mean tree moss?

Could be sap - as it ages it can go white.
posted by jkaczor at 7:19 AM on July 12, 2007

Best answer: Could it be foam from spittle bugs?
posted by ChuckLeChuck at 7:19 AM on July 12, 2007

I'm sure Chuck is right. I've seen spittle bugs myself and it's surprising just how much foam each one makes.
posted by Steven C. Den Beste at 7:40 AM on July 12, 2007

If they were hemlock trees, it might have been woolly adelgid.
posted by Miko at 7:43 AM on July 12, 2007

don't fireflies also come out of foam like that?
posted by gen at 7:45 AM on July 12, 2007

Response by poster: At first I couldn't tell from looking at the photos if it was cuckoo spit or spittle bugs, but according to Wikipedia they're the same thing. It seems cuckoo spit is the froth produced by spittle bugs.

So mystery solved. Thanks all.

Next time I see it (if I ever see it again), I'll have to look more closely to see if I can spot the actual bugs themselves.
posted by willnot at 8:13 AM on July 12, 2007

Just wipe the foam away, and you'll see the little green bug inside.
posted by weapons-grade pandemonium at 8:16 AM on July 12, 2007

Probably spit bugs--we don't have fireflies in western Canada (pity).
posted by Savannah at 7:34 AM on July 13, 2007