Velvet Mite

2014 December 31

On June 5, 2014, Sam found this on our brick pavers while helping clean up after Sandy built her new chicken run. It was only a bit over a millimeter long, and to the naked eye just looked like a tiny red-orange speck, zooming surprisingly rapidly across the ground. I had to use my camera with the high-magnification supplemental lens, and support it on the old microscope frame in order to focus properly. Eventually, I got it to hold still enough for pictures.

When touched, it would scrunch up into a little pellet that I could flip over to see the underside. It looks like it can pull part of the front of its body back inside its shell, almost like a turtle.

And, since it had some difficulty flipping itself back over, here’s another picture of the underside with its legs spread out.

We see these types of mites around with some frequency, it is one of the local Velvet mites, in the superfamily Trombidioidea. The mites in this superfamily vary wildly in size, with the local ones in Michigan being these nearly-microscopic things, while I understand that some of the species in warmer climates are nearly half an inch long. I kind of suspect, based on their size and the presence of “micro” in the family name, that ours are probably in the family Microtrombidiidae. And that indentation on the back of the abdomen is apparently characteristic of the genus Eutrombidium, a group of 22 known species that can only be told apart by microscopic examination.

The general assumption is that the color is a warning to predators that they are not good to eat[1], which raises the question of “just how bad of an idea is it to eat these?” Since I posted the last velvet mite pictures in 2008, I haven’t made much progress on the “finding out what they taste like” front. Ours are just so very tiny that it is hard to tell if I’m actually tasting them or not. There is general agreement that they taste bad, but the only person who actually has reported tasting one of the velvet mite species that is big enough for a human to taste appears to be Justin Schmidt. He is quoted in this article from the Christian Science Monitor as saying that they “taste nasty”, with no further elaboration. Not surprisingly, everyone else seems to take him at his word.

Note added 2016-5-20: I just started reading Justin Schmidt’s new book, “The Sting of the Wild”, and among other things he has a more thorough description of the taste of a velvet mite (note, though, that he is talking about a larger western species that is nearly the size of a honeybee, not our local pinhead-sized species). Still, he says:

“I placed a fat velvet mite on the tip of my tongue, the safest and most distant part from my throat, smashed it against my incisors, and chewed as best one can with incisors. The taste was truly amazing, stunning is perhaps a better word. After the 2-second analysis, I spat out the red juice like chewed tobacco. However, the flavor did not spit out with the crimson fluid. It was bitter, more bitter than quinine or any medicine I had ever tasted. It was also hot and burning, like a habanero pepper. Worse, it attacked the back of my throat and lingered there, that combination of bitter and corrosive heat. I was used to most nasty tastes leaving shortly after being spat out. Not this one. It lingered. The lingering seemed to last forever, an hour at least, before finally releasing its grip.”

At any rate, in general velvet mites are harmless[2] as long as you aren’t eating them. They start out as parasites on other insects when they are young (this particular genus evidently parasitizes grasshoppers), and then eventually turn in to free-roving predators when they get older. And since our local species never get much bigger than a couple of millimeters, you are only likely to see them if you are looking closely, in spite of their bright color.

[1] There is evidently some argument about this. Some people hypothesize that the red color may actually have evolved to protect them from ultraviolet light when they are exposed to the sun, and that any bad taste that they have was evolved later to deter predators from eating them now that they were bright, candy-apple red. I kind of suspect that this is not a cut-and-dried thing. Probably multiple selection pressures were all coming into play at once, and at this late date it is impossible to tell whether it was the UV protection or the warning-color function that first started the drive towards the orange color.

[2] Although, I understand that the chiggers are in this same superfamily. I’ve never lived anywhere that has chiggers, but I’m told that they are very uncomfortable. But, according to Wikipedia, even these are harmless as adults – it is only the nymphs that get onto your skin and digest parts of it.

6 Responses
  1. December 31, 2014

    1. It’s nice to know what they’re called. I see them a lot in summer, mostly when I’m using my laptop on a glass-topped bistro table on our screened porch. The porch has a brick floor so maybe they gravitate toward that material (except when they wander up the legs of the table), in which case the color would serve as camouflage.

    2. Maybe we should be calling them Red Velvet mites, after the popular-again cake/cupcakes, which IMHO are also not good to eat, in the sense of being long on color and short on taste.

  2. December 31, 2014

    It looks like it’s got plenty of folds that can expand to hold fluids sucked from its victims.

  3. Carole permalink
    December 31, 2014

    I seem the often, but had no idea of the detail of their appearance.
    Hope you find more fascinating insects in the new year.

  4. Katbird permalink
    December 31, 2014

    Has anyone tasted mites that are NOT red-colored for comparison? Happy New Year.

  5. January 1, 2015

    Be glad you’ve never shared the natural world with chiggers.

  6. January 6, 2015

    Anne: Now that you mention it, they could actually have fairly good camouflage on sand. When I look at sand under a microscope, it becomes a multicolored array of crystals, some of them red, and all of them about the size of these mites.

    Carole: There are evidently a bunch of different red mites like this locally, and at high magnification they have dramatically different body shapes. Some of them look more like pears.

    Katbird: I haven’t, no. If only because all of our local mites are similar size, and so I can’t get enough together for a taste.

    Marvin: Oh, I am glad, I am!

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