The E86 cluster bomb was developed as a biological weapon by the United States Army Chemical Corps and the United States Air Force beginning in October 1951. The Ralph M. Parsons Company was contracted to produce the E86 in October 1952. In 1953 procurement began for 6,000 E86 cluster bombs, with their production expected no earlier than 1958. When U.S. military munition requirements were reviewed in the first half of the 1950s, production and further development of the E86 was halted. The E86 cluster bomb supplanted technologies such as the E77 balloon bomb.
The E86 was similar to the M115 biological bomb, except it was larger. While the M115 weighed 227 kilograms (500 lb), the E86 was a 340-kilogram (750 lb) weapon. Regardless, operationally, the E86 was similar to the M115. It was designed as an anti-crop weapon; the U.S. biological weapons program produced three anti crop agents, wheat and rye stem rust and rice blast. The weapon was in a steel case and intended to be dropped from the exterior of an aircraft such as the B-47 or B-52. Sub-munitions included the E14 munition; the sub-munition was originally intended as anti-crop weapons as well, but was later altered and used in testing as the U.S. pursued an entomological warfare program.
- Whitby, Simon M. Biological Warfare Against Crops, (Google Books), Macmillan, 2002, pp. 167-69, (ISBN 0333920856).
- Wheelis, Mark, et al. Deadly Cultures: Biological Weapons Since 1945, (Google Books), Harvard University Press, 2006, p. 218, (ISBN 0674016998).
- Zilinskas, Raymond A. Biological Warfare: Modern Offense and Defense, (Google Books), Lynne Rienner Publishers, Boulder, Colorado: 2000, p. 68, (ISBN 1555877613).
- Kirby, Reid. "Using the flea as weapon", (Web version via findarticles.com), Army Chemical Review, July 2005, accessed December 28, 2008.