The blister beetle insects can usually be found in the Midwest & Southwest parts of United States.

Description and Distinctive Features: The black blister beetle has soft wing covers typical of beetles in the blister beetle family and the general body form is straight sided, with little bulging of the abdomen. Yes, ... A blister beetle is any of a group of meloid beetles which secrete a blistering agent known as cantharidin. A blister beetle, a bug that when crushed during harvest secrets a deadly toxin, is being blamed for the deaths of 14 horses. Living in an area where blister beetles are not uncommon – the central and eastern United States? If you see them, take them out of the plant. Typically, first cutting hay in Wyoming escapes blister beetle infestations because their peak swarming activity occurs later in the growing season. Size is largely dependent on larval diet and the sexes are similar in appearance. Blister beetle infestation is more likely to occur in later summer months in Wyoming. Horses that eat blister beetles can become severely ill or die from gastrointestinal, heart or kidney effects.

They are known as ‘Blister beetles’ because they secrete cantharidin, a poisonous chemical causing blistering of the skin and painful swelling. Adults are particularly attracted to alfalfa blooms, creating a serious forage health issue when transferred to stock feed. Blister beetles are much more problematic in the Great Plains than in the intermountain region. Cattle and sheep can also be sickened, but not usually to the same degree as horses.
Blister Beetle Alert Advisory for horse owners by Wyoming Livestock Board August 18, 2009. This sort of data can be useful in seeing concentrations of a particular species over the continent as well as revealing possible migratory patterns over a species' given lifespan.

Horse ranch near the Dells blames 'heartbreaking' loss of 14 horses on toxic beetles. Blister Beetles belong to the family Meloidae.
Currently, more than seventy-thousand five-hundred bugs species are found in America. Beetles of Wyoming Showcase listing of Beetles found in the state of Wyoming. If hay is at risk for blister beetle contamination, and particularly when it is sold for horse feed, insecticide use is justified.

Sometimes, blister beetles also occur in Canada and North Carolina, particularly in agricultural field. Blister Beetle This is the famed Spanishfly beetle that produces cantharidin, resulting in a blistering effect that is especially problematic with horse feed. The map below showcases (in blue) the states and territories of North America where the Blister Beetle may be found (but is not limited to). Livestock producers and especially horse owners need to be aware that blister beetles have been found in forage crops in central Wyoming.