False Chinch Bugs

I like to turn on the porch light at my Tucson, Arizona apartment to see what insects (and sometimes other organisms like Mediterranean Geckos) show up to visit. Well, most of the time I like to do this. Right now it is an exercise in annoyance as the porch light is quickly overwhelmed by tiny true bugs known as “False Chinch Bugs,” Nysius raphanus.

At only 3-4 millimeters, each individual bug is not terribly imposing. It is the sheer numbers of them that are a nuisance. They fly well and before you know it everything in the immediate vicinity is covered in them: you, your camera, your clothes, and any other objects close to the light source.

This tendency for Nysius to aggregate extends to their feeding habits as well. Hordes of them may literally suck the life out of certain plants, though they subsist for the most part on weeds. Severe damage to a variety of crops does occur on the rare occasions of large outbreaks of the false chinch bug. Their combined feeding, coupled with toxic secretions they inject in the course of feeding, can wilt foliage rapidly.

These insects are quite capable of migrating like a miniature swarm of locusts, too. They have been observed flying several hundred feet above the ground. It is suspected that an “aggregation pheromone,” a specific chemical compound emitted by the insects, is responsible for the mass behaviors.

Like all true bugs, false chinch bugs undergo “incomplete” metamorphosis. They hatch from the egg looking like miniature versions of adults, but lacking wings and reproductive organs. These babies are called “nymphs,” and they are sometimes mistaken for ticks by folks that find them on their clothing after a walk in a weedy area. They grow quickly, maturing in about three weeks. In some parts of North America they can produce three generations annually, overwintering as adults.

Thankfully, an onslaught of false chinch bugs is a brief phenomenon. They disperse within a few short weeks of their initial appearance. Meanwhile, they can be discouraged by keeping outdoor lighting to a minimum, and weeding in the spring to deprive them of the plants that they favor as nymphs.

There are many informative and reassuring internet resources for learning more about false chinch bugs, such as this fact sheet from Colorado State University Extension.

So far, my little population explosion seems minor by the standards I have read about, and until the monsoon rains kick in the diversity of species at my porch light will likely remain low anyway. Plus, leaving the light off should help ease my electric bill, or at least allow me the luxury of turning up the A/C a little higher.

Tucson Grasshopper Story on TV

This afternoon I was privileged to be interviewed by Delane Cleveland, a reporter for FOX News 11 at 9 regarding a sudden increase in the local grasshopper population. The insect in question is the Pallid-winged Grasshopper, Trimerotropis pallidipennis, normally quite abundant as it is, but occurring now in numbers that can be disturbing to some people. It pays to put this population boom in perspective, however, and to let people know of easy ways to deal with them while they are here.

The Pallid-winged Grasshopper is a member of the family Acrididae, or “short-horned grasshoppers,” named for the short antennae (in contrast to katydids and crickets which have very long antennae). While some members of this family have a truly migratory phase called a “locust,” this species flies shorter distances in vastly smaller numbers.

Locusts represent an actual physiological change in the body of a normally solitary species, triggered by crowding to the degree that the young (nymph) insects are literally rubbing elbows with each other. This physical contact causes them to not only become more gregarious, but leads to a sleeker, longer-winged adult than usual. Nymphs of locusts will march in armies, devouring nearly every green piece of vegetation available. As they grow, eventually molting into adults, they retain their social nature. Pushed by strong storm fronts, they fly hundreds of miles, continuing to lay waste to the landscape.

There is historical documentation of infrequent outbreaks of the Pallid-winged Grasshopper, much more severe than we are seeing currently, that were problematic in rural, agricultural areas in Arizona. This year’s population represents a mere nuisance by comparison.

Should you still worry, what do you do? Pallid-winged Grasshoppers feed primarily on grasses, but will also eat some herbaceous vegetation (called “forbs”), so homeowners may wish to cover such vulnerable plants in the garden during the grasshoppers’ layover. Also, the grasshoppers are attracted to lights in droves during the overnight hours. Simply turning off outdoor lighting will help to decrease their numbers, at least in your own private yard. Consider wearing sunglasses, as some errant ‘hoppers, disturbed by your footsteps, may fly up in your face. Please avoid the use of chemical controls, as those poisons can be harmful to the natural predators of grasshoppers, such as spiders, birds, and lizards. Remember, such population increases are temporary, a fleeting blip in nature’s seasonal time frame.

My compliments to Mr. Cleveland and his videographer for producing a fine story, free of the sensationalism that the media often adds to such natural phenomenon. Stay tuned for more on grasshoppers, and other insects you are likely to encounter throughout the year.