Red Plant Bug Nymph on Black Locust

2014 June 25

On July 12, 2013, Sam and I took a small bedsheet, put it under a small Black Locust tree, and whacked the branches to see what would fall out. We turned out to get a number of these little red bug nymphs with a white band around their waists.

They were pretty small, only about 2-3 mm long, and so I only got a few reasonably non-blurry pictures.

Nymphs like this are hard to identify, because they are often poorly documented and generally grow up to have very different coloration. That said, the best bet appears to be a plant bug in the genus Lopidea, who not only have nymphs that look just like this, but are also often found on Black Locust trees.

The red color looks like warning coloration, and since the bark and leaves of Black Locust are toxic, there are good odds that these plant bugs concentrate the toxins from their food and are dangerous to eat as well.

In general, I would say that if you want to find colorful insects, the first thing to do is to figure out which of your local plant species are most toxic. Then look for the insects that eat that toxic plant.

4 Responses
  1. June 25, 2014

    Are the plant toxins inert material that build up in the body of the bug? What triggers a toxin to do its dirty work? Do they react with the iron in our blood to cause problems? Looking it up, insects have hemolymph instead of blood. From what I can gather, hemolymph doesn’t have Fe in it.

  2. June 25, 2014

    Well, in this particular case, the Black Locust toxin is a Toxalbumin, , which are a class of toxins that work by inhibiting protein synthesis. And since practically everything a cell does involves making proteins, this is pretty serious. The toxalbumins are evidently fairly fragile compounds that can be destroyed by heat and by the digestion process, but they are so highly toxic that even traces getting through the gut into the blood can be poisonous. If these bugs are using the toxalbumin for defense, I’d expect them to be holding it sequestered outside of their cells somewhere.

    Plants are really into chemical warfare (since they obviously can’t run, hide, or fight the way animals do), so there are lots and lots of other kinds of toxins available for the insects to co-opt. Including cyanide, which is probably the one you are thinking of that would react with iron atoms in critical enzymes like hemoglobin and cytochrome C oxidase. I’m working on a big posting along these lines that will go up at the end of the year, so I’ll talk more about it later. In particular, I’ll try to find out exactly how they store the toxins in their bodies so that they aren’t killed by them themselves.

  3. Dianna permalink
    July 2, 2018

    I found one of these nymphs on a small black locust seedling. Not far from it on the branch was a Beech Blight Aphid. What is the name of the nymph with red abdomen and white band?

  4. July 2, 2018

    Dianna: They don’t appear to have a common name, they are just true bugs in the genus Lopidea

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