Blister Beetles

Boy do I have a crop of them this year. I kill em off then about a week later I get more. Apparently this is a good climate (hot and dry)for them.

I had a problem with them a few weeks back and I dusted the garden with sevin dust and have not had them since. Before I did that you could walk out there and they would crawl all over your shoes to the point you almost could not see your shoes

Didn't know what they were, so googled them. Looks like they are nasty little critters - or at least the blisters they inflict are nasty.

ive not seen as many this year but weve a fair crop. horse folks here swear they will kill a horse if they get in hay. but they dont like their hay sprayed either. i know they will raise a blister on you.

Blister beetles are extremely toxic to horses. Just a piece of one can kill a horse. Check with the vet.

I think it takes about 40 of them to kill a young colt.
They are nasty little critters and this year's 2nd. cutting of alfalfa was crawling with them. I have my swather set so it doesn't "crimp" when I cut hay.

(quoted from post at 10:36:55 07/31/12) I think it takes about 40 of them to kill a young colt.

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A veterinarian told me ONE blister beetle was enough to kill a grown horse.

I just repeated what my vet told me a few years ago when I asked him about the blister beetles in my alfalfa.


After doing a Google search, I found this information at,.....
http://www.ag.ndsu.edu/pubs/plantsci/pests/e1002w.htm

All species of blister beetles produce a toxic substance called cantharidin. This toxin is a well-known vesicant (blister-causing substance) that is quickly absorbed upon contact and causes inflammation and blistering of internal and external body tissues. The amount of toxin produced varies considerably between species. The ash-gray, black, striped, and margined blister beetles are a few of the more common species which produce levels of cantharidin capable of poisoning livestock. Livestock come in contact with blister beetles when they consume infested alfalfa hay. Horses are most susceptible to the toxin, while sheep and cattle are more tolerant. The reaction to the toxin depends upon the relative dose; enough ingested beetles can be lethal to any animal.

Researchers have determined the lethal dose of cantharidin to be approximately 1 milligram per kilogram of horse body weight. This means that about 200 blister beetles could have levels of toxin sufficient to kill an adult horse. In addition, an average of 5.0 mg of cantharidin has been found in striped blister beetles, which indicates that 30 to 50 adults could be potentially lethal. However, even a few beetles may cause colic in horses. Cantharidin can also be lethal to cattle and sheep. Although less susceptible than horses, they may experience symptoms if enough beetles are consumed. A laboratory study has shown that cantharidin can reduce the digestibility of certain forages. Little information or research exists addressing the effects of cantharidin on lactating dairy cows. Symptoms of sublethal poisoning include depression, diarrhea, elevated temperatures, increased pulse and breathing rates, and dehydration. There is also frequent urination, especially after the first 24 hours. If cantharid poisoning is suspected, a veterinarian should be contacted immediately.

The toxin is extremely stable. Crushing or chemically killing the beetles will not diminish the toxin's activity. Even the remains or dried juices from crushed beetles on the hay may cause severe digestive and urinary tract ailments in domestic animals.

(quoted from post at 16:50:47 07/31/12) I just repeated what my vet told me a few years ago when I asked him about the blister beetles in my alfalfa.


After doing a Google search, I found this information at,.....
http://www.ag.ndsu.edu/pubs/plantsci/pests/e1002w.htm

Researchers have determined the lethal dose of cantharidin to be approximately 1 milligram per kilogram of horse body weight. This means that about [color=red:b6d82a64ab]200 blister beetles could have levels of toxin sufficient to kill an adult horse.[/color:b6d82a64ab] In addition, an average of 5.0 mg of cantharidin has been found in [color=red:b6d82a64ab]striped blister beetles, which indicates that 30 to 50 adults could be potentially lethal[/color:b6d82a64ab].

Click to expand...

This makes more sense to me.
Otherwise, if it took 1 beetle or a piece of a beetle to kill a horse, there would be a lot of dead horses everywhere those beetles are found. And that just isn't the case.

(quoted from post at 15:13:09 07/31/12)

(quoted from post at 16:50:47 07/31/12) I just repeated what my vet told me a few years ago when I asked him about the blister beetles in my alfalfa.


After doing a Google search, I found this information at,.....
http://www.ag.ndsu.edu/pubs/plantsci/pests/e1002w.htm

Researchers have determined the lethal dose of cantharidin to be approximately 1 milligram per kilogram of horse body weight. This means that about [color=red:53c53f656d]200 blister beetles could have levels of toxin sufficient to kill an adult horse.[/color:53c53f656d] In addition, an average of 5.0 mg of cantharidin has been found in [color=red:53c53f656d]striped blister beetles, which indicates that 30 to 50 adults could be potentially lethal[/color:53c53f656d].

Click to expand...

This makes more sense to me.
Otherwise, if it took 1 beetle or a piece of a beetle to kill a horse, there would be a lot of dead horses everywhere those beetles are found. And that just isn't the case.

Click to expand...

The alfalfa I cut for my neighbor last week was so thick with beetles, that I'm sure if my swather's rollers had been set to "crimp",... just one small square bale would have contained enough toxin from squished beetles to kill more than one horse.
The windrows were just full of live beetles after the hay was down.

we were hit couple weeks ago, i don't garden, but they were rough on the weeds,