Katydid spit on a finger
Katydid spit (Photo credit: John Drebus)

The seasonal approach of the days of summer means hot nights, baseball games, family vacations, pool parties, and lots of insects. Summer is insect time for sure! These cold-blooded organisms have to “make hay when the sun shines” in order to complete their life cycles before temperatures decline for the year.

Grasshoppers are insects that we don’t often see until the good ol’ summertime. That is because grasshoppers spend the winter in egg masses in the soil. Those eggs hatch in late spring, and the young hoppers are small and inconspicuous for weeks.

But as grasshoppers mature into adult stages, they grow in size and develop wings. Adult grasshoppers not only jump, but also fly, and that means these insects become more visible to casual observers. That is especially true in grassy habitats where they are often found – after all, these insects are called grasshoppers for good reason!

Grasshoppers are not the favorite insects of most people. Butterflies they are not. That is probably the reason why, in the original storyboards produced 75 years ago for the Disney cartoon movie “Bambi,” a grasshopper didn’t appear in the final product. Here’s the story. The unnamed grasshopper that was created to represent the smaller creatures of the forest was very grumpy and ornery. Ultimately, an engaging little bunny named Thumper filled that small-creature role. I’m not surprised. Most humans prefer fuzzy, warm animals to coldblooded exoskeleton-encased insects. The grumpy grasshopper got booted and Thumper became a star!

Even though grasshoppers can be pests to farmers and gardeners, these jumpers in the grass have always held a fascination for young children who happen to encounter them. The grasshoppers jump or fly short distances to escape potential predators such as kids of the human sort. When that happens, the chase is often on.

Kids sometimes actually catch grasshoppers for an up-close look. And that is where the real action begins. First, the grasshopper kicks with those powerful jumping legs, using the spines of the back legs to gouge skin. If that doesn’t let the grasshopper escape, it resorts to another trick: defensive regurgitation.

Defensive regurgitation has long been recognized as something that many grasshoppers and katydids practice. A few species of birds are also known to engage in a behavior that most people consider a disgusting activity. For instance, the subarctic seabird called the northern fulmar vomits a bright orange substance called stomach oil. Here in North America, nestlings of turkey vultures will projectile vomit when you approach their nest. Considering that the parents of these young turkey vultures feed their kids on regurgitated food from their craw – with that food being flesh from carrion they have consumed – you can imagine that it is not the best smelling-stuff in the world. I know based on practical experience, because I accidentally encountered a turkey vulture nest in an abandoned barn some years ago!

Growing up, I called the fluid produced in the mouths of grasshoppers “tobacco juice.” Exactly why the material came to sometimes be called tobacco juice is not known. However, it does resemble, in color and consistency, the spit produced by people who chew tobacco. Some say the term might have originated because of the fact that grasshoppers sometimes feed on tobacco plants.

Entomologists have long assumed that the tobacco juice of grasshoppers was a type of defensive regurgitate. That conclusion is supported by the observation that the fluid is expelled when the insect is in some physical danger. However, there has not been a lot of research done on the subject. A recent study showed that apparently, the regurgitate might ward off smaller predators such as ants, but larger predators were not affected.

The grasshopper tobacco juice is a combination of partially-digested plant material and digestive enzymes. This much I know: if you catch a grasshopper or katydid and hold it, the insect will produce the fluid out of its mouth. If you get the fluid on you, it will stain your skin and be difficult to wash off. And oh, by the way, the grasshopper spit does taste bad. If you don’t believe me, the next time you get some grasshopper tobacco juice on your hand, taste it. Friends, that is what scientists call research!

Subscribe to the On Six Legs podcast.