Scientist's efforts to improve honey bees led to spread of 'killer bees'.

A 1957 incident in Brazil led to the unintended spread of Africanized honey bees, commonly referred to as "killer bees," after 26 queen bees escaped from a research facility near Rio Claro. This event initiated their proliferation across two continents, eventually reaching the United States decades later, as reported by The Economic Times. The University of Florida’s Institute of Food and Agricultural Sciences now ranks Africanized honey bees among the top invasive insect threats in America, although their origins were rooted in a scientific effort to enhance honey production for Brazilian farmers.