It's that time of the year - everywhere I look I see telltale white foamy clusters on my plants.
This foamy sack is actually a nursery for baby spittlebugs, the nymphs, as they grow to size (eating all the way). The adult female lays her eggs in this foam, which protects the nymphs.
These nurseries (in my garden, anyway), seem to mostly occur on older, larger, woody plants. The nymphs do suck juices from the plant as they mature, but do little damage. As you can see in the picture below (I'm sorry, I cannot remember the name of this particular kind of spirea - you know how I forget to label things and I've had this one for ten years), the spittlebugs are not doing any significant harm. The plant is large and bushy, needs cutting back every fall, and produces masses of tiny white umbels that little native bees seem to love.
I seem to find evidence of spittlebugs only in the shady, wet part of our garden - the Woodland Garden, under the Brazilian Pepper tree .
When it starts to look as though the nymphs are taking over, I get out the hose, and blast the foamy clusters with water. This does the trick.