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Last summer my garden was under attack! We’re talking one day I had this lush beautiful garden and the next morning total destruction! Wondering what could cause that much damage in only a few hours? BLISTER BEETLES! That’s right folks a tiny little blister beetle.
This tiny pest comes with a massive appetite for all things green.
A few things I learned about blister beetle bugs while I was researching how to get rid of them.
They come it a lot of colors everything from solid black/gray to striped and spotted. No matter the color they have come in swarms. If you have a lot of grasshoppers you could be at risk for the blister bugs as they love grasshopper eggs.
The name is no joke they release a substance that can cause irritation to your skin. The ‘caustic fluid’ blister beetles secrete called cantharadin and is toxic if swallowed. It lasts after the blister bug dies. Felt that first hand. Not fun. I brushed one while picking some green beans and it left an itchy spot. Others report serious blisters after contact. They can also harm farm animals if ingested.
They’re found on tomato, potato, eggplant, peppers, and other vegetables. I didn’t notice them eating my green beans as much as they were taking refuge there from the birds and me. Sorry, not sorry I was taking out every one of those little suckers I could. Lol. They also didn’t seem to care for okra.
They seem to be highly attracted to pigweed, ragweed, and ironweed suggest removal. I don’t want anything that will attract these little bastards.
Frequent inspection of your garden will help keep you on top of these pests as well as others. I noticed a lot of strange black stuff all over the ground and plant steams. Soon I figured out it was their poop. Ick.
I’m no expert on these little pests but I can tell you what I tried and how it worked for me. The only thing we didn’t try was chemicals because we don’t use them. Period.
Handpicking
This method has the potential to work when there’s only a small amount of blister beetles. I would recommend wearing rubber gloves and long sleeves that come the top of gloves. Drop them in a container of soapy water.
As I mentioned I ended up getting some irritation on my skin from touching them. I had thousands of beetles so this method proved pretty much useless.
Food Grade Diatomaceous Earth
This seemed to work but it took to long once they had taken up residence in my garden. I also found myself spreading the earth every couple of days. Watch the time of days when you spread this as it is harmful to bees.
I tried to keep it off blooms but it wasn’t always possible. It combats several different pests from the garden but doesn’t harm earthworms.
Neem Oil
Had little to no effect on them. I sprayed them directly and all the plants I don’t think it even slowed them down a bit!
Blister Beetle Fact: they are the possum of garden pests. If disturbed they play dead!
My plan of attack for next year to prevent total destruction. I’m burning off my garden area this winter. From my research, they can overwinter in the soil. After the massive amount I had, I’m sure they laid eggs everywhere.
I also plan on spreading diatomaceous earth everywhere early on in the season and keeping it. I’m also considering insect row covers. Not only for the blister beetles but hornworms and cabbage worms were very troublesome.
In another article, one reader suggested a mixture of equal parts all-purpose flour and lime. Not sure if it’ll work or not but at least it’s safe to use and affordable.
I’ve also read you can use Spinosad with good results. I honestly don’t know much about it but will be researching it and may try it if I get over ran with them in the future.
Do you have any tips or tricks you’ve used to battle these beetles? Leave em in the comments I’ll try about anything to keep garden pests at bay.
If you enjoyed this article you might like one of these:
Garden Pest: Tomato Horn Worm Edition

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Wow- just when we figure out how to deal with one pest, along comes another. Wendie and I haven’t seen any around here, but we’ll be on the lookout. Hand picking works for us on pests if they haven’t gotten out of control, but that lime and flour mix you mentioned is at least economical enough to give it a try. Best of luck and we’ll be sending you positive vibes:)
Thanks! I hope I never have them like we did last year, but I’m sure there will be another pest to deal with. Seems to be the natural cycle of life! However this year I am prepared better to ward off the little devils!
Oh, I hate those bugs with a passion! We don’t get a lot of them, however, the ones we do get my 6 barn cats love, so they don’t stay long. It is weird because they don’t bother my veggies, they seem to like my herb garden. Good luck with those pesky critters!