Jerry Prosnick, age 13, of Gilbert, Minn., for his question:
What causes those foamy deposits on tall grasses?
A female frog or toad may deposit a gob of foamy looking stuff in the moist greenery. Close inspection reveals that the clear bubbles are balls of jelly surrounding round, black tadpole eggs. Those air filled bubbles of frothy foam found on grasses are deposited by insects.
Gobs of this foamy froth can be found clinging to grassy blades of the fields and wayside, among the needles of pine trees and on the leaves of certain shrubs. Most of them appear in the summer, but a few survive through the winter. They are deposited by cercopids of the insect family cercopidae, named for an agile, tree hopping monkey of the old world.
About 30 cercopid insects are native North Americans. Some peop1e call them froghoppers because the adults resemble frisky little tree frogs. Others call them spittlebugs because of their foamy deposits on the greenery. The average adult is a wide, squat bug less than half an inch in length. Two similar pairs of wings are neatly folded to his sides, but he seldom mes. He is an agile jumper who prefers to travel from leaf to leaf in sprightly hops the female cercopid lays her eggs in early spring, but they do not hatch until the following spring. She may cover them with a shield of fragile looking foam that
Actually is tough enough to survive the winter. The eggs hatch into small, pale, wingless copies of their parents. If you investigate a summery gob of the foam, chances are you will find one or two of these helpless cercopid nymphs inside.
The ghostly green creatures sit there completely submerged in their own bubble bath. It screens out the fierce summer sun, hides them from their enemies and raindrops slide off its slippery surface. The newly hatched nymphs create their own bubble baths. A gummy substance is made by glands in the seventh and eighth segments of the abdomen, a thin, liquid comes from an opening near the tail and air comes from under the hard, abdomen skin. The three substances are squirted out at the same time and mix together to form the mass of frothy foam.
Cercopids are sippers and suckers with jointed beaks to take sap and juices from their favorite plants. They tend to weaken the grasses, clover, shrubs and other plants of their choice. Some cercopids select evergreens and harm growing pine trees by stealing their juicy sap.
The cercopidae family is a subdivision of the homoptera order of insects. The order name refers to the two similar pairs of wings that moat, but not all, oe these insects have. One family includes the camouflaged leafhoppers, ranging from modest little leapers of brown to gaudy fellows striped with reds and purples. Some .look like leafy green tents. Aphids and scale insects are also sap sipping cousins of the frog hopping spittlebugs.