As producers are beginning the haying season, there are always environmental things to prepare for as well as knowing what is in the hay you are cutting. This year there have been sightings of a potential nuisance commonly found in alfalfa hay. The blister beetle is not a common problem in Montana, especially in this area, but with this summer turning hot and dry this year; there is concern for more populations to arise. They are commonly found in alfalfa hay and when not handled properly can cause an issue to producer’s livestock. This is because blister beetles; when disturbed, expel a toxin that can contaminate your hay. The toxin they create is called a cantharidin, this is exuded from them when disrupted, such as swathing or baling. This cantharidin causes blisters when it comes in contact with skin, and is also known for being harmful to animals, especially horses. If consumed there can be blistering in the esophagus and stomach, kidney and heart function can be affected as well. Anyone one of these things can then lead to the potential death of the animal. This only happens though, if there is a cluster of beetles wrapped in a bale together and then an animal consumes that section of the bale filled with beetles. As stated before, in Montana we do not typically have any major issues with blister beetles; but with this hot, dry year there have already been sightings of small populations in alfalfa fields. Field experts are encouraging producers to keep a watchful eye out for them; just to air on the side of caution, especially if they are selling their hay to the public.
To stay on top of preventing this potential problem, the Montana State University Extension has outlined some helpful management tools that most producers have already implemented in their operations. Obviously, monitoring what is in your alfalfa field is the number one way to prevent this. Also, recommendations are to use harvest equipment that allows beetles to escape or fall through the hay as it is being cut. Kansas State University found the use of self-propelled swathers without conditioning rollers but with wind-rowing attachments is safer than mower conditioners and sicklebar mowers. They claim sicklebar mowers, were found to cause significant mortality if recently cut hay was driven over. Continuously driving over recently mowed alfalfa hay caused mortality of those beetles still in the cut forage. Allowing beetles to disperse after mowing and before baling can lower the number of beetles incorporated into bales hay. Producers can use insecticides, but researchers do not recommend using them due to the potential of residual activity, and other environmental issues that could occur.
As stated once again, Montana does not have problematic areas of blister beetles. With the few sightings there is still not a major concern, but as always we want producers to be informed on the constant changes the agricultural industry faces. As we gear up for another haying season the team at R&J Ag Supply is here to support producers and help with any of your haying needs.