Spit!

Have you ever been working in a garden, strolling through the woods, or looking at plants in a greenhouse when you noticed what looked like a wad of spit on a leaf or in the crotch of a plant? Perhaps, in a lapse of judgment, you touched the spit and noticed it was both oily and slippery, and kind of sticky at the same time. If you were so brave, and you kept a very sharp eye, you may have seen one of these guys jump or crawl out of the stuff you left on the plant:


Aptly called the "spittlebug", as well as the "froghopper", this insect belongs to the same order as cicadas and aphids. The cute green ones like our friend up there are the nymph of the species, meaning they haven't yet reached sexual maturity, and have to molt one more time before they're adults. You'll only ever find the nymphs in foam - the adults don't usually make foam, although they have the same diet as their younger brethren. They are more often the ones called froghoppers, because they look like really tiny frogs, and because they can jump huge distances. The first time I saw one, it was on a strawberry leaf until I went to catch it and it leapt off. I started hootin' and hollerin' to the rest of the crew because I thought I had found a tiny frog and I wanted to show them!


So you're probably wondering what the foam actually is. Not if you're smart, you're not! Skipping the rest of this post would behoove those readers with weak constitutions. Insects don't have salivary glands, so it's obviously not actually spittle. To figure this 'mist'-ery out, we need to look at what the spittlebug nymph eats. They survive by drinking plant sap and eating the xylem, one of the two types of tissues that transports nutrients through plants. Specifically, it transports water and nutrients from the roots to the leaves (the other type, phloem, carries sugars from the leaf, where they are produced, to the rest of the plant).

Most of their nutrients come from the xylem itself, but they drink a great deal of the sap as well. There are conflicting theories about how they form the spittle. One says they mix the sap with air in little organs inside their bodies, while the other says they do a little dance to create the foam as it runs down their legs. Either way, it passes through their systems and out of their anuses on its way to becoming foam.


Okay, that was a little gross. I apologize, but I wanted to get it out there before I go any further. Also, now you know one of the many reasons to wash your local food - even berries - before you eat it. We clean most of our crops a little, but I can't guarantee that strawberry you're eating never had an insect's excretions on it. As much as we may squirm at that idea, the foam performs a number of functions for the spittlebug. It keeps them moist and cool on hot, sunny days, and protects them from predators. Even if a bird or larger insect knows to look inside the collections of spit to find these guys, the stuff is really slippery, as I said before. I've accidentally brushed the spit a few times, and the spittlebug inside was always left there, looking around before it hopped away to find a new place to feed.

The foam also serves a useful purpose for us humans! I can't back this up with any website or evidence, just an anecdote. I was picking strawberries one day when I brushed my hand against a nettle, or something similar. After finding the plant and ripping it out with my multi-tool, I was left with an itchy red patch on my finger. Normally, I can put up with the discomforts of my job, but this one was really bugging me. I couldn't cure it by swimming in a cold pool like I did when I got stung at age ten, so I thought, "What would Bear Grylls do?" Realizing he would probably find something in his immediate vicinity and use it to treat the nettle sting, I looked at what I had with me. After preliminarily eliminating strawberry juice as a treatment, I went looking for a little pocket of spit, and found one handily. Two topical applications, spaced about 15 minutes apart cleared it right up! So if you're out in the woods and you run into a patch of nettles, look to the pine trees, the spittlebug's favorite food, for help.

These insects are still pests, cute or not. Feeding on the xylem hinders the plant's ability to transport water from the root to the stalk and the leaves. One individual won't do much damage by itself, but a swarm of these guys can lower a crop's yield. Don't panic if you find them, though! Panicking leads to nasty things like insecticide, and that's never good for your plants. I'm happy to report that all you need to get rid of these expectorating nuisances is a hose or even a watering can, which will do your plants some good anyway.

Squishily,
The Regular Farmer