MTPR

Grasshoppers: 'A Crisp, Electric Spark of Joy'

Aug 1, 2015

Did you know grasshoppers sing with their legs, and hear with their abdomens? Learn more with this field note from the Montana Natural History Center.

I’m looking at the front of my car, which is covered with the remains of grasshopper bodies after a drive back to Montana from Utah. A slightly greenish, bitter smell still clings to the engine. By coincidence I came across a field note about grasshoppers, written a while back by Leeann Drabenstott, which gave me a little more to think about while I cleaned my hood.

In Aesop’s fables, she wrote, the grasshopper, in contrast to the industrious ant, represent how we think we shouldn’t be; lackadaisical and irresponsible.

Mostly grasshoppers are considered pests, and not without reason. From 1984 to 1987, grasshoppers infested and devoured some 55 million acres of rangeland in the western United States. I didn’t know this though when on a recent walk through a local meadow I found myself fascinated with the insects that kept hopping across my path. I laughed once I was finally face-to-face with one of the brown-green creatures. Its face looked like that of an elderly man who always holds his mouth slightly open, ancient and waiting.

Grasshoppers belong to the order Orthoptera and are in the family Acrididae. There are nearly 400 species in the 17 western states.

As the name suggests they feed mostly on grasses and other foliage, but also at times will eat dead insects, including other grasshoppers.

You mostly see grasshoppers in action in the meadows and grasslands on hot, dry days in mid to late summer. Aesop’s fable suggests that they are simply having fun and wasting time when they should be storing up supplies for the winter. Actually, their hopping serves as a defense against predators, whose movement they can detect with one or both eyes. They are equipped with two sets of wings to assist in flying once they have propelled themselves in a jump, using the power of their long hind legs.

When I picked up one of the hoppers in the meadow, it spit up a dose of what looked like tobacco juice. It is a regurgitation of the foul-smelling and highly acidic content of its fore gut, meant to deter predators. Also, if trapped by a hind leg, the grasshopper can expel that leg by a contraction of a special muscle at its base.

Natural enemies of the grasshopper include birds like kestrels and meadowlarks, and insects such as ants and Robber flies. They are also the target of many agricultural pest-management programs.

Grasshoppers are very sensitive to extremes in air temperature or moisture. Because they have limited means to regulate their body temperature, they gradually become paralyzed and die as winter comes on. Even a cool or rainy summer evening, during which hoppers usually crawl under canopies of grass, can cause a decrease in their movement. Once the sun returns, grasshoppers often orient themselves in an open spot like sun bathers; body lined up with the sun’s rays, head furthest from the sun, trying to let the warmth strike as many surfaces as possible. Sometimes they even lean onto one side exposing their abdomens, a maneuver called flanking. After an hour or two they begin to feed and hop again.

To propagate their species before winter hits, grasshoppers mate toward the end of summer. Females dig into the soil and lay fertilized eggs. The embryos begin to develop while it is still warm, but enter a dormant period once the ground turns cold. In late spring, the nymphs emerge and being foraging on nearby grass. Nymphs molt, or shed their exoskeleton, five times before they are adults with fully developed wings.

Once grasshoppers are able to mate, males attract females with mating songs produced through a process called stridulation. A stridulatory peg on each of the hind legs is scraped against a raised vein on each forewing, creating a song or signal that is particular to each species. They hear the sounds through an auditory organ located on the first segment of the abdomen.

While grasshoppers are often considered destructive creatures, I prefer to think of them in the words of John Muir: "a crisp, electric spark of joy."

"Field Notes" is produced by the Montana Natural History Center.

(Broadcast: "Field Notes," 7/21/15. Listen weekly on the radio, Sundays at 12:55 p.m., Tuesdays at 4:54 p.m. or Fridays at 4:54 p.m., or via podcast.)