Defoliation bacilli bombs, made between 1932 and 1933, were used by the

Imperial Japanese Army The was the official ground-based armed force of the Empire of Japan from 1868 to 1945. It was controlled by the Imperial Japanese Army General Staff Office and the Ministry of the Army, both of which were nominally subordinate to the Emperor o ...

to spread bubonic plague across China. The deployment of these lethal munitions provided the Japanese with the ability to launch devastating

biological attack Biological warfare, also known as germ warfare, is the use of biological toxins or infectious agents such as bacteria, viruses, insects, and fungi with the intent to kill, harm or incapacitate humans, animals or plants as an act of war. Bio ...

s, infecting agriculture, reservoirs, wells and populated areas with anthrax,

plague Plague or The Plague may refer to: Agriculture, fauna, and medicine *Plague (disease), a disease caused by ''Yersinia pestis'' * An epidemic of infectious disease (medical or agricultural) * A pandemic caused by such a disease * A swarm of pe ...

-infected

flea Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about long, a ...

typhoid Typhoid fever, also known as typhoid, is a disease caused by ''Salmonella'' serotype Typhi bacteria. Symptoms vary from mild to severe, and usually begin six to 30 days after exposure. Often there is a gradual onset of a high fever over several d ...

dysentery Dysentery (UK pronunciation: , US: ), historically known as the bloody flux, is a type of gastroenteritis that results in bloody diarrhea. Other symptoms may include fever, abdominal pain, and a feeling of incomplete defecation. Complications ...

and cholera. The alumni of

Unit 731 , short for Manshu Detachment 731 and also known as the Kamo Detachment and Ishii Unit, was a covert Biological warfare, biological and chemical warfare research and development unit of the Imperial Japanese Army that engaged in unethical h ...

, the unit that prepared these weapons, became top bioweapons researchers and were not prosecuted as war criminals.

References

Biological weapons Biological_weapon_delivery_systems Japanese biological weapons program {{weapon-stub