Spittle Bug! The rather disgusting wad of spit on this weed is the nest of a small beige, green, or yellow insect. The foam is where it lays its eggs and protects them with the wet glob. Gross, HUH? Diatomaceous Earth works well on drying the wad of spit out and ultimately the bug and eggs. A hard shot of water will slow them down. Hand picking them out of the moist glob works, though only a true gardener may want to do this!