I’m willing to wager that for many visitors to Bug of the Week, somewhere back in your childhood you have a memory of your mother telling you not to spit because it wasn’t polite. Of course when you were not under her watchful eyes, you and your friends worked on perfecting the fine art of spitting. As a youngster, I often visited the meadow and wondered about the prowess of who or what could produce the ubiquitous spittle decorating so many herbaceous plants in the field. The remarkable life of spittle bugs was revealed later. Spittle bugs, a.k.a. froghoppers, are a large family of insects technically known as Cercopidae. These sucking insects belong to a renowned clan called Hemiptera that includes stink bugs, assassin bugs, and aphids we met in previous episodes.
Many adult froghoppers sport rather drab colors of gray or brown or cryptic shades of green and are not often seen during casual excursions to the garden. However, immature stages of froghoppers are called spittle-bugs and their frothy masses are a sight well known by most gardeners. While many have observed the spittle produced by spittle-bug nymphs, I’m guessing that few have cleared away the bubbles to see the rather adorable green nymphs enshrined within. Spittle is a fairly innocuous mix of excess plant fluid voided by the nymph, proteinaceous glandular secretions and air bubbles introduced by clever contortions of its body. The spittle serves to keep the developing nymph moist and insulated from extreme temperatures and also serves as a deterrent from attack by stinging parasitoids and hungry predators. Would self-respecting birds really wade through a glob of spittle in search of a buggy meal? I think not.
After molting several times within their bubble home, nymphs turn into winged adults. Adults suck plant sap to obtain nutrients and excrete excess sap in the form of honeydew, as do other sap-suckers including aphids and soft scale insects. Here in Maryland, most spittlebugs and froghoppers cause no economic damage. However, our featured creature of the day can become abundant enough to damage clover grown as forage for livestock. Next time you walk in the meadow, fear not the spittle and take a moment to brush back the bubbles and enjoy these curious sap-suckers.
Beneath the froth a spittle bug nymph feeds and grows. After being displaced by a finger, it settles back into its froth. Adult spittle bugs are a little hard to spot on vegetation and when disturbed they live up to their name of froghopper, jumping fast at both normal and 70% slow speed.
The great reference “An Introduction to the Study of Insects” by Donald Borer, Dwight De Long, and Chuck Tripplehorn was used as a reference for this episode. We thank intrepid Dr. Shrewsbury for plunging a finger into the frothy spittle of the meadow spittlebug.