A Week's Worth of Thistle

Episode 2

Another search of the thistle left me somewhat disappointed. The Fourlined Plant Bug had gone and the tortoise beetle larvae, as if channeling their common name, seemed to have only grown and not moved. I looked on every leaf for something exciting, and finally turned to the stem.

A pocket of foam made me curious. I thought that it might possibly be an egg case, which was exciting, but then I reasoned that the foam was too fragile and wet to be a proper egg case. So, yet again, I decided to look it up. 

The most likely cause of the foam was a Spittlebug. Spittlebug's are the larval form of insects commonly called Froghoppers. The adults are the tiny, pill-shaped bugs (and it's a Hemipteran so that's correct) that land unexpectedly on arms and legs, and upon closer inspection, will explosively jump away.

The larvae, or nymphs since they are hemimetabolous, feed on the plant's inner fluids, which are then converted to the foam. The foam, like the tortoise beetle larva's shield, provides multiple forms of protection. For one, it keeps the nymph out of view and prevents it from desiccating, and it also helps regulate temperature. 

Again, these guys are considered pests, but one or two will only cause minor damage to a plant that it can easily bounce back from later. If you would like a view of these guys, you can actually use a blade of grass to break up the foam to see a tiny off-white nymph underneath.