Project Bellweather, which studied mosquitoes, was investigated by the U.S. Army as a possible biological weapon, according to a declassified 1977 Pentagon document reported by the Daily Mail.
The 69-page document, available through the Defence Technical Information Centre, details the secret project and other insect-related military tests, including Operation Drop Kick and Operation Big Buzz.
The Pentagon conducted real-world experiments between September and October 1959 to examine how mosquitoes behaved under different environmental conditions. Researchers studied how swarms might perform if released against enemy troops or populated areas.
The tests used human-biting Aedes aegypti mosquitoes, a species linked to diseases including dengue fever, yellow fever, chikungunya and Zika. The mosquitoes used in the experiments were not infected with disease-causing agents.
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Researchers measured how far the insects could travel, how long they survived after dispersal and whether they would seek out and bite human hosts. The document said the deliberate use of infected arthropod vectors against enemy targets held “great strategic potential.”