On Spittlebugs…or ….Why are my Pants Wet!?!
Anyone who has walked through a field of tall grass on a dry day only to find their pants wet has asked the same question….”what gives?” Chances are, you’ve encountered a population of spittlebugs! And specifically, you’ve just walked through a spittlebug “nursery” of sorts. Let me explain.
Spittlebugs are in a group of insects (Order Hemiptera) whose mouthparts have evolved into a permanent straw…they stick that straw into their food and suck out the liquid inside. Spittlebugs are exclusively vegetarian…they stick their mouth “straw” into a plant and suck out the sap inside. The problem is that plant sap (xylem, in this case) is not especially nutritious, and so they have to suck out quite a lot of the liquid to survive. And with so much liquid going in, a lot has to go out, too! Spittlebug babies ‘drink’ plant sap, digest what they can, add certain other components (mucopolysaccharides, proteins, and air bubbles), and pass the excess liquid out of their bodies, creating what can only be described as a blob of liquid that looks and feels just like spit.
The baby spittlebugs live inside this spit blob, happily sucking plant sap and growing up. The spit protects them from drying out (dessication), being eaten (predation), and having other organisms invade their bodies (parasitism). Once they complete their development and become adults, they leave their saliva-like homes and become free-living spittlebugs that jump and fly about, searching for dates and mates.
I’m a ‘new guy’ at the North Carolina Museum of Natural Sciences, having only arrived in April. My research focuses on the worldwide diversity and evolution of spittlebugs and their close relatives (amazing insects, including cicadas, treehoppers, leafhoppers, and planthoppers). Stay tuned for more blog posts on these crazy, charismatic critters (yes, bugs can be cute!!!).