We enjoyed my brother-in-law’s rhubarb chard for supper Monday night (in southern Missouri). Tuesday morning, Ann came back inside from the raised bed where it was growing with a look of horror on her face. Here’s why.
Overnight, the 4 x 4 foot patch had been discovered by a legion of 3-striped blister beetles. It was almost as if they had emerged out of the soil. There were probably 2 – 3 hundred of them, and they had eaten or spoiled with their droppings the entire planting. There was nothing to do but to spray them with Sevin, and everything above the soil will have to be cleared away and put in a safe place where other animals can’t get to it.
The poison from these beetles that creates the blistering for which they are named is called cantheridine, and it is extremely toxic. You can find all sorts of dire warnings about horse fatality if consumed even a small amount of dead beetles, especially in alfalfa where the beetles might get baled into the hay.
If you happen upon this beetle, leave it alone and don’t let your kids handle it. If they do, be sure and wash their hands well. The toxin is persistent long after the beetle dies, so even dead beetles are a threat.
This is the mythical “Spanish Fly” we heard about in high school, but thankfully, did not have access to for its purported aphrodisiac properties. Here’s what Wikipedia contributes about it uses:
Early uses
Medical use dates back to descriptions from Hippocrates. Plasters made from wings of these beetles have been used to raise blisters. In ancient China, the beetles were mixed with human excrement, arsenic and wolfsbane to make the world’s first recorded stink bomb.[6]
- In Roman times, Livia, the scheming wife of Augustus Caesar, slipped it into food hoping to inspire her guests to some indiscretion with which she could later blackmail them.[7]
- Henry IVÂ (1050—1106) is known to have consumed Spanish fly at the risk of his health.
- In 1572, Ambroise Paré wrote an account of a man suffering from “the most frightful satyriasis” after taking a potion composed of nettles and cantharides.[8]
- In the 1670s, Spanish fly was mixed with dried moles and bat’s blood for a love charm made by the magician La Voisin.[9]
- It was slipped into the food of Louis XIV to secure the king’s lust for Madame de Montespan.
- In the 18th century, cantharides became fashionable, known as pastilles Richelieu in France.
- The Marquis de Sade is claimed to have given aniseed-flavored pastilles that were laced with Spanish fly to prostitutes at an orgy in 1772. He was sentenced to death for poisoning and sodomy, but later reprieved on appeal.[10
The natural world is strange and even more so the human world, as that Wikipedia example illustrates. Wow. Never heard of any of this (except good old Spanish Fly, heard about by every teenager, back in the 50’s.)
You learn something new every day. They look more like lightening bugs than flies.
I’ve been told also to wash hands after squishing Colorado Potato Beetles because the yellow/orange pigment they leave behind can be toxic.
Blister Beetles do look like lightning bugs! Thanks for posting Fred, I too had no idea about these creatures. I’m battling flea beetles on my cabbage, broccoli, and brussel sprout plants. Despite their now lacy looking leaves, the broccoli and cabbage are still producing. Now I’m going to make sure that flea beetles don’t leave behind anything toxic! We already ate one harvest of broccoli though, and we’re fine so far!