Spotted Blister Beetle in Washington

Subject:  Spotted Blister Beetle
Geographic location of the bug:  Tonasket WA
Date: 07/12/2021
Time: 10:20 PM EDT
Your letter to the bugman:
I’ve been pulling pigweed for 4 weeks and about 2 weeks ago this mass of beetles show up. Hundreds and hundreds, practically overnight.They don’t bite or sting or eat anything I’m trying to garden. I don’t bother them. 4-5 days ago, I’m weeding and my arm starts to itch drastically. I look at the spot, not a bump, not a rash, but a blister!.Still, no idea as to what. 3 days later, aha moment. Turns out blooming alfalfa and pigweed family are a favorite food of adult blister beetles. Get rid of it and the beetles will eat your garden. YAY! I don’t have to weed anymore! There are over 7,000 varieties. Average behavior, adults live about 3 months June to Aug., lay eggs in the dirt, and the larvae spend the rest of summer, fall, winter and spring eating grasshopper eggs, (sometimes bees if they can find them) and hibernating (? is that the word?) The blister is truly awe inspiring. And, purportedly, 6 grams of dead crushed dried beetles in one serving of alfalfa hay eaten by a horse can kill the horse. Wild Birds find them delicious, (I read). The blistering agent survives to irritate the entire digestive tract in most mammals. They usually survive, but may get sick. I’ve been seeing grasshoppers, so maybe the beetles know something about the future I don’t. They don’t bother me and they eat grasshopper eggs and pigweed! Yay, go blister beetle.
How you want your letter signed:  Cathy

Spotted Blister Beetles

Dear Cathy,
We love, love, love your submission.  It is awesome that you have done so much research in the effort to make your gardening more labor efficient.  Blister Beetles (including the Spotted Blister Beetle,
Epicauta maculata, which is pictured on BugGuide) do have interesting and complex life styles, and many members of the family are able to excrete the compound cantharadin which can cause blistering in human skin and is also the active component in the alleged aphrodisiac Spanish Fly which is made from the ground bodies of a green European Blister Beetle, Lytta vesicatoria.

1 thought on “Spotted Blister Beetle in Washington”

Leave a Comment