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.
Here too: the area under the black light is solidly covered. And yes, I've carried some inside with me, I just see one running along the keybord
ReplyDeleteWhat about these bugs? I've been seeing them by the zillions here in SoCal, but in the daytime. And they're super tiny, probably only 2mm. But they sure look like what you have.
ReplyDeleteCindy: Looks like something in the same family at least...I've added your blog to my link list, so very sorry to have overlooked you for so long! Keep up the great work :-)
ReplyDeleteThanks, Eric. One of these days, I'm going to update my blog and put up links to all the new people I've found, too!
ReplyDeleteHow do you get rid of these bugs they're all on my backyard doors and house??
ReplyDeleteI never give pest control advice here. Further, these bugs do not bite and rarely, if ever, do irreparable harm to plants. They are at most a fleeting nuisance not worthy of intervention. Thank you.
DeleteHi Eric, Do you know what the eggs of the false cinch bugs look like or where they are laid? Also, they are seed bugs, aren't they (Lygaeidae)? If so, do they feast more on seeds or plants? I'm getting so many questions about these guys right now in my Maricopa County (Arizona) gardening group and I want to be giving out accurate information about them. Thanks! Nancy
ReplyDeleteHi, Nancy. I recommend consulting the University of Arizona entomology department, and/or website:
Deletehttps://extension.arizona.edu/false-chinch-bugs
First encounter with these bugs after living in Tucson for 29 years. It was like a biblical plague. The biggest frustration was their infiltration of the house, particularly our main bathroom which was rendered unusable and closed off until they ran their course. When it seemed like the swarms had finally died off, we had a couple of days of peace only to be swarmed again by babies…like moving specks of dirt, again, all over the bathroom (and outside all over the cactus). What a funky experience.
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