May 13, 2007 - Frothy Bug Welcome to the Nature Notebook. Walk along a meadow and you’ll see what looks like spit on certain plants. Rather than being left by a passerby, this foam is created by an insect, known quite appropriately as a spittlebug. Related to aphids and cicadas, it belongs to the order Homoptera or true bugs. It is the immature spittlebug or nymph that creates the “spit” while sucking sap from the plant. Positioned head down, the young spittlebug sucks in the sap, pumps it through its body, and expels what is left. As this sap mixes with air it turns to foam, much like the froth on a cappuccino. For the spittlebug, the foam provides a safe haven from predators. The foam also cools the young spittlebug and prevents it from drying out. If you want to see the spittlebug, just blot off the spit and take a peek. This is PPL's naturalist, Jon Beam, with the Nature Notebook for WVIA.