Operation Big Itch

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Operation Big Itch was a U.S. entomological warfare field test using uninfected fleas to determine their coverage and survivability as a vector for biological agents. [1] The tests were conducted at Dugway Proving Ground in 1954.

Entomological warfare (EW) is a type of biological warfare that uses insects to attack the enemy. The concept has existed for centuries and research and development have continued into the modern era. EW has been used in battle by Japan and several other nations have developed and been accused of using an entomological warfare program.

Flea order of insects

Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that survive as external parasites of mammals and birds. Fleas live by consuming blood or hematophagy, from their hosts. Adult fleas grow to about 3 mm or .12 in long, are usually brown, and have bodies that are "flattened" sideways, or narrow, enabling them to move through their host's fur or feathers. They lack wings, but have strong claws preventing them from being dislodged; mouthparts adapted for piercing skin and sucking blood, and hind legs extremely well adapted for jumping. They are able to leap a distance of some 50 times their body length, a feat second only to jumps made by another group of insects, the superfamily of froghoppers. Fleas' larvae are worm-like with no limbs; they have chewing mouthparts and feed on organic debris left on their host's skin.

Biological agent pathogen that can be weaponized

A biological agent—also called bio-agent, biological threat agent, biological warfare agent, biological weapon, or bioweapon—is a bacterium, virus, protozoan, parasite, or fungus that can be used purposefully as a weapon in bioterrorism or biological warfare (BW). In addition to these living and/or replicating pathogens, toxins and biotoxins are also included among the bio-agents. More than 1,200 different kinds of potentially weaponizable bio-agents have been described and studied to date.


Depicted Micrograph of the common Flea. Micrographia Scheme 34.png
Depicted Micrograph of the common Flea.


Operation Big Itch was a September 1954 series of tests at Dugway Proving Ground in Utah. [2] [3] The tests were designed to determine coverage patterns and survivability of the tropical rat flea ( Xenopsylla cheopis ) for use in biological warfare as disease vector. [3] The fleas used in these trials were not infected by any biological agent. [4] The fleas were loaded into two types of munitions and dropped from the air. [4] The E14 bomb and E23 bomb, which could be clustered into the E86 cluster bomb and E77 bomb, respectively. [3] When the cluster bombs reached 2,000 or 1,000 feet (600 or 300 m) the bomblets would drop via parachute, disseminating their vector. [3]

Biological warfare use of biological toxins or infectious agents with the intent to kill or otherwise neutralize enemies as an act of war

Biological warfare (BW)—also known as germ warfare—is the use of biological toxins or infectious agents such as bacteria, viruses, and fungi with the intent to kill or incapacitate humans, animals or plants as an act of war. Biological weapons are living organisms or replicating entities that reproduce or replicate within their host victims. Entomological (insect) warfare is also considered a type of biological weapon. This type of warfare is distinct from nuclear warfare and chemical warfare, which together with biological warfare make up NBC, the military initialism for nuclear, biological, and chemical warfare using weapons of mass destruction (WMDs). None of these are considered conventional weapons, which are deployed primarily for their explosive, kinetic, or incendiary potential.

Vector (epidemiology) agent that carries and transmits an infectious pathogen into another living organism

In epidemiology, a disease vector is any agent who carries and transmits an infectious pathogen into another living organism; most agents regarded as vectors are organisms, such as intermediate parasites or microbes, but it could be an inanimate medium of infection such as dust particles.

The E86 cluster bomb was an American biological cluster bomb first developed in 1951. Though the U.S. military intended to procure 6,000 E86s, the program was halted in the first half of the 1950s.

The E14 was designed to hold 100,000 fleas and the E23 was designed to hold 200,000 fleas but the E23 failed in over half of the preliminary Big Itch tests. [3] E23s malfunctioned during testing and the fleas were released into the aircraft where they bit the pilot, bombardier and an observer. [4] As a result, the remaining Big Itch tests were conducted using only the smaller capacity E14. [3] Guinea pigs were used as test subjects and placed around a 660-yard (600 m) circular grid. [3]

Guinea pig domesticated rodent species from South America

The guinea pig or domestic guinea pig, also known as cavy or domestic cavy, is a species of rodent belonging to the family Caviidae and the genus Cavia. Despite their common name, guinea pigs are not native to Guinea, nor are they biologically related to pigs, and the origin of the name is still unclear. They originated in the Andes of South America, and studies based on biochemistry and hybridization suggest they are domesticated descendants of a closely related species of cavy such as C. tschudii, and therefore do not exist naturally in the wild.


Big Itch proved successful, [3] [5] the tests showed that not only could the fleas survive the drop from an airplane but they also soon attached themselves to hosts. [6] The weapon proved able to cover a battalion-sized target area and disrupt operations for up to one day. [3] The one-day limit was due to the activity of the fleas; the air dropped fleas were only active for about 24 hours. [2]

See also

Operation Big Buzz was a U.S. military entomological warfare field test conducted in the U.S. state of Georgia in 1955. The tests involved dispersing over 300,000 mosquitoes from aircraft and through ground dispersal methods.

Between April and November 1956, the U.S. Army Chemical Corps conducted Operation Drop Kick to test the practicality of employing mosquitoes to carry an entomological warfare agent in different ways. The Corps released uninfected female mosquitoes into a cooperative residential area of Savannah, Georgia, and then estimated how many mosquitoes entered houses and bit people. Within a day the mosquitoes had bitten many people. In 1958, the Corps released 600,000 mosquitoes in Avon Park, Florida.

Operation May Day was a series of entomological warfare (EW) tests conducted by the U.S. military in Savannah, Georgia in 1956.


  1. Bubonic plague is an infection of the lymphatic system, usually resulting from the bite of an infected flea.
  2. 1 2 Rose, William H. "An Evaluation of Entomological Warfare as a Potential Danger to the United States and European NATO Nations", U.S. Army Test and Evaluation Command, Dugway Proving Ground, March 1981, via thesmokinggun.com , accessed December 25, 2008.
  3. 1 2 3 4 5 6 7 8 9 Kirby, Reid. "Using the flea as weapon", (Web version via findarticles.com ), Army Chemical Review , July 2005, accessed December 23, 2008.
  4. 1 2 3 Croddy, Eric and Wirtz, James J. Weapons of Mass Destruction: An Encyclopedia of Worldwide Policy, Technology, and History, (Google Books), ABC-CLIO, 2005, p. 304, ( ISBN   1-85109-490-3).
  5. Novick, Lloyd and Marr, John S. Public Health Issues Disaster Preparedness, (Google Books), Jones & Bartlett Publishers, 2001, p. 89, ( ISBN   0-7637-2500-5).
  6. Leeson, Kate. "Biological Weapons: Bioterrorism and the Public Health", Medical Association for the Prevention of War, 2000, p. 12, accessed December 25, 2008.

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