During a recent hike, I noticed this white foamy substance on certain green plants along the path. The substance resembled a dime-sized
or slightly smaller ball of styrofoam. I looked closer. At first, I thought it was debris that had lodged itself at the fork of the plant’s branches. Then I considered that it might be oozing sap due to an injury. However, there were white balls on many different kinds of plants. Surely they weren’t all injured.
My next guess was that the sphere was some sort of insect’s nest. Finally, I was getting close.
That insect is known as a Froghopper (Cercopoidea). What I was seeing was the protective nest of the spittlebug, which is the froghopper nymph. That substance isn’t spit, however. It’s kind of like insect urine.
As the insect nibbles on the plant stem, it ingests the sap and excretes it out the other end. As it passes through, it mixes with air and other glandular secretions. The air forms bubbles resulting in its texture.
The foam then protects the nymph from predators, swings in temperatures, and keeps the nymph from drying out.
Perhaps you’ve noticed this white foam as you pick strawberries? It’s common in some parts of the country. Not to worry. The substance is not toxic and can be removed easily with a good washing.
This is just another example of the ingenuity of organisms to live symbiotically, to make the most of the resources around themselves without grossly endangering others.
For more information – https://hort.extension.wisc.edu/articles/spittlebugs/