Does anyone know anything about blister beetles?

This last batch of alfalfa has a bunch of blister beetles in it. Normally, I'll see only one or two a year total. I've picked out at least 20 just in this last week.
I know the beetles can be toxic to livestock if they ingest enough of them. I'm just wondering if anyone has any 1st hand experience with this & what do you do.

I don't have any first hand experience, however I do know that it can be deadly.

And it takes 2-3 beetles to kill a horse. I have friends who lost several miniatures do just a few ground up fragments of dead beetle--invisible, unless you knew exactly what you were looking for.

Do NOT feed this hay. And don't feed any hay if you find even a speck of one blister beetle in it. Are you absolutely positive that they're blister beetles, though?

Solution? Throw out the hay. There's no way you can effectively pick them out, and it's sure as hell not worth the risk. Find a new supplier. Stop feeding alfalfa.

Blister Beetle Poisoning / Cantharidin toxicosis

Thank you for the information. We've pretty much decide not to feed this batch anymore anyway.

I'm pretty sure the bugs are blister beetles although not positive. I got a bite on my hand around the time we started feeding this alfalfa which is fairly similar to the photos I've seen on the web of blister beetle sores.

I don't really have a lot of options short of going out of state as far as suppliers go. We don't feed a lot of alfalfa to begin with (its more of a garnish) so its no big deal to stop.

Question -are blister beetles usually only a problem in alfalfa hay? Most the stuff I've read on the web leans towards this. Also, the few I've seen over the years have been in alfalfa.

I feed bermuda as my horses primary feed. Should I be worried about blister beetles getting in the bermuda? I haven't seen any yet, but...

I don't know for a fact that other kinds of hay can't get blister beetles, but I do know that alfalfa and the other legumes are by far the most commonly afflicted type.

I do believe that in general, alfalfa is the only type of hay afflicted by blister beetles. Of course it could be in other hay, but I think that's like saying their COULD be rat poison in other hay - always a possibility but the chance is so slim it could only be called fluke at best of it happened.

I've never heard of it being a problem in other hay, as per articles or personal experience/stories.

Thanks again for the input.
From what I've been reading so far, the problem seems to be mostly with alfalfa.

[QUOTE=flytobecat;958109] I got a bite on my hand around the time we started feeding this alfalfa which is fairly similar to the photos I've seen on the web of blister beetle sores.[QUOTE]


This sounds fairly suspect as you should not have any live beetles in the hay from last year when the hay was baled. They would not survive the winter in the baled hay.

Basically, almost any hay can have beetles from the midwest; however flowering plants are more suspect than non flowering hays. You can also buy 1st or 4th cutting hay as the beetles are not in the flying stage of their life cycle during those cuttings in general. Additionally, you can generally buy hay north of the mason-dixon line and the beetles generally do not thrive in the northern cliamates.

It would be a horse that is highly alerigic to the beetles that dies from one beetle as this chart shows.

Table 1: A comparison of the relative toxicity to horses of three species of blister beetles.SpeciesEstimated number of blister beetles required to cause mortality in a horse weighing:
275 lbs. 550 lbs. 825 lbs.
Black blister beetle 5501, 1001, 700
Spotted blister beetle 175 345 520
Three-striped blister beetle 40 80 120

Talk to your hay supplier - they should be knowledgeable about beetles. If you are still worried about the beetles, switch your hay to a different lot number of hay. Many hundereds of thousands of tons of alfalfa are fed each year with no ill effects - talk to your supplier!