Alfalfa-contamination
Guides
Tegrodera aloga
iron cross blister beetle
Tegrodera aloga is a large, conspicuous blister beetle endemic to the Sonoran Desert. Adults are easily recognized by their black bodies with contrasting yellow and red spots and a distinctive black cross pattern on the elytra. The species is notable for its aposematic coloration, which advertises the presence of cantharidin toxins used for defense. Adults feed on spring blossoms and occur in large aggregations during mating and feeding. The species poses a documented risk to livestock, particularly horses, when contaminated alfalfa hay is ingested.