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Chronology of CBW Incidents Targeting Agriculture 1915-2008

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This chronology includes allegations, threats, failed attempts, and confirmed incidents, of agro-terrorism and agricultural sabotage that utilized chemical or biological agents to harm or kill economically important crops. Crops include livestock and plants raised for human consumption.

Biological Incidents

1915-1918 / Argentina, France, Romania, U.S., UK
The German secret service mounted a covert biological weapons campaign during WWI. The pathogens used included P. mallei (glanders) and B. anthracis (anthrax), as well as a wheat fungus. While this program mostly targeted horses and other pack animals, German agents also infected cattle and sheep. The program appeared to have pleased the Germans as can be seen from a cable between a command module and a German agent: "[p]lease instruct Arnold [the agent's codename] to continue his successful activity against cattle. His work against grain is to be suppressed as it promises little success."[1]

1940-1945 / China
Among a range of agents, Japanese BW units utilized morbillivirus and B. anthracis (anthrax) against (among other animals) cattle, in their conflict with the Soviets in Northern China. In addition, Japanese units released fleas (likely X. cheopis) infected with Y. pestis (plague) over wide areas of China in their efforts to subdue the Chinese population and to test the efficacy of their weapons. While the flea releases appear to have targeted mainly humans, Japanese research projects prior to the releases had experimented with the use of infected fleas to kill cattle.[2]

1943 / Isle of Wight, UK
Richard Ford, a prominent British naturalist, claims that Germany dropped special bombs containing Colorado potato beetles on the UK during WWII, which was the reason for their first appearance in parts of the UK. According to Ford, the bombs were made of cardboard and each contained between 50 and 100 beetles. The alleged attack was, by Ford's account, kept secret by the British government to avoid raising public alarm. Benjamin Garrett has disputed Ford's claim, stating that although German scientists did considered employing potato beetles for crop destruction, "there is scant evidence to suggest the Colorado potato beetle ever made it into battle." Garrett believes that the insect's mysterious appearance in England resulted from an accidental introduction, probably via imported food stuff from the U.S., where the beetle had been endemic since 1874.[3]

1950 / East Germany
In a Ministry of Forestry report dated June 15, 1950, the government of the German Democratic Republic accused the United States of disseminating Colorado potato beetles over its potato crops in May and June of 1950.[4]

1952 / Kenya
The Mau Mau, a nationalist liberation movement, poisoned 33 cattle at a British mission station using what is believed to have been a local toxic plant known as African milk bush (S. compactum).[5]

1962-1996 / Cuba
Between 1962 and 1997, the Cuban government accused the U.S. of having attacked its human, animal, and plant populations with biological weapons on at least 21 occasions. According to Raymond Zilinskas, the Cubans have alleged that the U.S. biological attacks caused ailments such as Newcastle disease among poultry (1962), African swine fever among pigs (1971, 1979-80), tobacco blue mold disease (1979-80), sugarcane rust disease (1978), dengue hemorrhagic fever among humans (1980), and an infestation of the thrips insect in 1996 (see separate discussion below). According to Zilinskas, the most likely explanations for the outbreaks and the infestation are that they were accidentally imported in the course of normal commerce or were carried to the island by natural forces.[6]

1983-1987 / Sri Lanka
Sometime between 1983 and 1987, the Tamil militant group Liberation Tigers of Tamil Elam released a communiqué, threatening use of biological agents against Sri Lanka's major ethnic group, the Sinhalese, and its agriculture. In regards to agriculture, the threat warned of the destruction of tea plants and rubber trees.[7]

1984 / Queensland, Australia
Queensland's State Premier received a letter threatening that unless the government implemented prison reforms within twelve weeks, wild pigs would be infected with foot-and-mouth disease. Ultimately, this incident proved to be a hoax, as the perpetrator turned out to be a 37-year-old murderer serving a life sentence in a local prison. Queensland's State Premier received a second similar letter from an unidentified source later that same year, which probably was sent by the same culprit.[8]

1989 / Los Angeles County
In late 1989, the Breeders, a previously unknown group (or individual), sent letters to Los Angeles Mayor Tom Bradley and various newspapers, including the Fresno Bee and Los Angeles Times, claiming that in protest of the State's ongoing pesticide use to combat Medfly infestation, it was breeding Medflies (C. capitata) and planned to release them throughout Southern California. The Breeders claimed that by doing so, the existing "Medfly problem would become 'unmanageable.'" During the fall and winter of 1989-1990, the Medfly infestation of Southern California did in fact display several unusual characteristics, which entomologists could not explain, such as the abnormally low ratio of Medfly larvae to adults. The identity of the letters' author(s) remains unknown to this day.[9]

1996-1997 / Cuba
Cuba alleged that the U.S. had deliberately released melon thrips (T. palmi) over the island that came to severely damage its agriculture during autumn 1996. According to the Cubans, an aircraft operated by the U.S. Department of State released thrips over Cuba on October 21, 1996, while in transit to Colombia. After the U.S. denied the allegation, Cuba requested that a consultative meeting be held to investigate its allegation as provided for under Article 5 of the 1972 Biological and Toxin Weapons Convention (BWC). Accordingly, a consultative meeting of the BWC States Party took place August 25-27, 1997, to consider the Cuban allegation. Of the national representatives who took part in this meeting, 10 wrote opinions holding that there was no link between the U.S. aircraft's overflight and the infestation; two stated that there was insufficient evidence to make a conclusive finding, and one, North Korea, believed that the U.S. was responsible for the infestation.[6]

June 1, 2000 / West Bank
Palestinian news sources reported that Israelis from the Efrat settlement in the West Bank, deliberately released sewer water onto agricultural fields owned by Palestinian farmers in Khadder village, near Bethlehem. According to the farmers, the release of wastewater was a recurring action designed to force them to abandon their land, which would allow Israeli settlers to annex the areas. Farmers estimated their losses to have been approximately 5,000 dollars.[10]

September 2001 / Dublin, Ireland
During an epidemic of foot-and-mouth disease in the U.K., field-sports enthusiasts claimed animal rights activists threatened to reintroduce the causative virus into areas recently cleared of the outbreak. The purported reason for the threatened action was to block the resumption of foxhunting, which the UK government had temporarily stopped to prevent the virus from being spread by humans to unaffected animal populations (humans are not vulnerable to foot-and-mouth disease). Garda (the Irish police) officers questioned some activists in late September and the Irish Department of Agriculture carried out an investigation of a subsequent outbreak of the disease, but found no evidence of intentional spread.[11]

May 9, 2005 / New Zealand
The New Zealand Prime Minister's office received a letter on May 10, 2005, claiming the author had released foot-and-mouth disease virus on a small adjacent island the previous day. The letter threatened additional releases if the government failed to accede to the author's extortive demands, which included undertaking certain tax reform measures. Six days later, the Dominion Post received a letter, which authorities believed came from the same author, claiming the prior letter was a hoax. Authorities found no evidence of foot-and-mouth virus during the time period.[12]

Chemical Incidents

1952 / Korea
U.S. forces used herbicides on a limited scale during the last year of the Korean War.[13]

1962-1970 / Vietnam
In its fight against North Vietnamese regulars and its guerilla clients in South Vietnam, the U.S. military used four types of air-sprayed herbicides, including Agent Orange, for the purposes of jungle canopy defoliation and crop destruction. The U.S. military did this in order to deprive its enemy of cover and food.[14]

March 9, 1970 / Ashville, Alabama USA
The poisoning of the water supply of a 1,000-acre farm owned and operated by a group of Black Muslims resulted in the death of 30 cattle. According to the farm's manager, the poison, which a local veterinarian identified as cyanide, appeared as a pinkish-white material found on and around rocks in the stream. Reports alleged that a local chapter of the Ku Klux Klan (a white supremacist group) had been responsible for the contamination.[15]

May 1970 / Angola, Mozambique, Guinea Bissau
On July 21, 1970, the Popular Movement for the Liberation of Angola (MPLA) issued a statement accusing Portugal of having employed herbicides and napalm to kill crops in eastern Angola. According to the MPLA, two-thirds of crops under its control had been destroyed. A New York Times article reported that U.S. diplomats found traces of chemical anti-plant agents that might have been used by the Portuguese against crops. The UN General Assembly adopted a resolution on December 14, 1970, that called on Portugal to desist from using chemical or biological weapons against Angola, Mozambique, and Guinea Bissau.[16]

1976-1980s / Laos, Kampuchea (Cambodia)
Beginning in 1976, communist forces, supported by Soviet technical and logistical personnel, were alleged to have utilized chemical agents against resistance forces and their supporters in Laos and South Vietnam. Reports alleged that this usage expanded in 1978 as chemicals were also used against the democratic resistance in Kampuchea. The communist forces allegedly used sprayers mounted on aircraft, mortars, grenade launchers, rockets, and landmines to disseminate chemical weapons agents (and possibly toxins) over H'mong (Laos) and Khmer (Kampuchea) villages. A 1982 U.S. intelligence report claims that "…vegetation samples showed the presence of mycotoxins…" which is believed to be an active ingredient in the agent referred to as 'yellow rain,' so named for its distinctive hue. Although the majority of attacks seems to have been undertaken for the purpose of injuring humans directly, allegedly some of the chemicals destroyed crops.[17]

March 1977 / Uganda
The Ugandan People's Passive Resistance Front threatened to destroy Uganda's coffee and tea crops in order to deny the government revenue. The Front claimed that income from coffee sales was "…used to buy arms for genocidal purposes." They also issued a combination appeal and threat, which stated, "[w]e ask the world not to touch Ugandan goods or else face the consequences."[18]

1979-1984 / Afghanistan
During the Soviet invasion of Afghanistan, and perhaps even prior to it, Soviet forces allegedly employed a variety of chemical, and some biological, agents against the mujahideen. The specific agents that were used have not been identified with certainty due to the inability of investigators to collect samples quickly enough to prevent their degradation. However, from indirect evidence it appears that the agents used by the Soviets were phosgene, phosgene oxime, diphosgene, lewisite, sarin, soman, sulfur mustard, and possibly others. Further, the Soviets may also have utilized trichothecene mycotoxins, thought to be a component of 'yellow rain.' Most of the chemical attacks affected the inhabitants of villages and the crops they were raising. In one instance a Soviet chemical officer told a U.S. journalist, "…his mission was to examine villages after a chemical attack to determine whether it was safe to enter…" In 1982, a U.S. scientific team assessing the situation received samples of contaminated wheat. The Soviet defector Ken Alibek alleges that Soviet forces also utilized biological agents, including P. mallei (glanders). Glanders is an enzootic disease that affects many animals important to agriculture and also causes disease among humans.[19]

January 1996-May 1998 / China
Sometime between early 1996 and May 1998, a Chinese farmer used rat poison to kill four of his neighbors and 12 water buffaloes. The farmer was apparently jealous of his neighbors because they were "better-off." Locals at first mistook the poisonings for an outbreak of mad-cow disease, which caused a brief panic outbreak.[20]

December 1996-May 1997 / Berlin, Wisconsin, USA
The police chief of Berlin, Wisconsin, received an anonymous letter in late December 1996, claiming that feed products at National By-Products Incorporated had been tainted with a pesticide and that the police should expect "large scale animal mortality." National By-Products is a supplier for the Purina Mills animal feed plant in Fond du Lac, WI. Purina feed was tested and found to contain low levels of contamination (one or two parts per million) on January 2, 1997. The following day, Purina stopped a shipment of 300 tons of feed bound for Wisconsin, Illinois, Iowa, and Michigan. Officials from the Wisconsin Department of Agriculture, Trade, and Consumer Protection announced that tallow stored at National By-Products Inc. had been deliberately contaminated with chlordane, an extremely toxic and persistent insecticide that was widely used in the U.S. between 1947 and the late 1980s. On September 14, 1999, Brian "Skip" Lea was indicted for product tampering after a police investigation found that he had twice contaminated the tallow. Lea owned a rival animal food processing facility, as well as dead livestock removal company.[21]

October 22, 1997 / Bethlehem, West Bank
Palestinian news sources reported that Israeli settlers from Gosh Etzion sprayed a chemical on Arab grape farms proximal to the Ertas and Khader villages south of Bethlehem. Allegedly, the Israelis ruined hundreds of grapevine trees and up to 17,000 metric tons of grapes.[22]


1. Martin Hugh-Jones, "Wickham Steed and German biological warfare research," Intelligence and National Security, 7:4 (1992): 381-383; W. Reginald Hall and Amos J. Peaslee, Three Wars with Germany (NY: G.P. Putnam's Sons, 1944): 85-87, quote from p. 86, the authors note that over 40 cables dealt with disease cultures; Henry Landau, The Enemy Within: The Inside Story of German Sabotage in America (NY: G.P. Putnam's sons, 1937): 167-171.

2. Sheldon H. Harris, Factories of Death: Japanese Biological Warfare 1932-45 and the American Cover up (New York: Routledge, 1994): 79-80, 96; Calum G. Turvey et al., "Economics, hysteresis and agroterrorism," Paper presented at Canadian Agricultural Economics Society 2003 Annual Meeting at Rutgers University, pp. 21; Friedrich Frischknecht, "The history of biological warfare," Science & Society 4, no. Special Issue (2003): S47-S52.

3. Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare, Vol. I (NY: Humanities Press, 1971), 223; Benjamin C. Garrett, "The Colorado Potato Beetle goes to war," The Monitor: Nonproliferation, Demilitarization, and Arms Control (Sept. 1996), 2-3.

4. Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare, Vol. I (NY: Humanities Press, 1971), 224.

5. P.W. Thorold, "Suspected malicious poisoning," Journal of the South African Veterinary Medical Association, 24 (December 1953), 215-217; Zygmunt F. Dembek and Edwin L. Anderson, "Food, waterborne, and agricultural diseases," in Medical Aspects of Biological Warfare, ed. Martha K. Lenhart, Dave E. Lounsbury, and James W. Martin (Fort Sam, Houston, Texas: Borden Institute, 2007), 21-38, according to the authors, Mau-Mau is a Swahili acronym for "let the white man go back abroad so the African can get his independence." (p. 27).

6. Raymond Zilinskas, "Cuban allegations of biological warfare by the United States: assessing the evidence," Critical Reviews in Microbiology, 25:3 (1999), 173-227.

7. M.R. Narayan Swamy, Tigers of Lanka, From Boys to Guerrillas, (Delhi: Konark Publishers, 1994); Dagmar Hellmann-Rajanayagam, The Tamil Tigers: Armed Struggle for Identity, (Stuttgart: Franz Steiner Verlag, 1994); Edgar O'Balance, The Cyanide War: Tamil Insurrection in Sri Lanka 1973-88, (Washington: Brassey's U.K., 1989); Rohan Gunaratna, War and Peace in Sri Lanka, (Sri Lanka: Institute of Fundamental Studies, 1987), 51-52; Citations above obtained from W. Seth Carus, Bioterrorism and Biocrimes: The Illicit Use of Biological Agents in the 20th Century, Working Paper (Center for Counterproliferation Research, National Defense University, August 1998/July 1999 revision), 174-175.

8. Tony Duboudin, "Australian livestock threatened," The Times (London), January 21, 1984, 5; Tony Duboudin, "Murderer in court over virus threat," The Times (London), February 22, 1984, 5. Citation above obtained from W. Seth Carus, Bioterrorism and Biocrimes: The Illicit Use of Biological Agents in the 20th Century, Working Paper (Center for Counterproliferation Research, National Defense University, August 1998/July 1999 revision), 171-172.

9. John Johnson, "Female Medfly found in Sun Valley close to area targeted earlier," Los Angeles Times (4 January 1990): B3; Ashley Dunn, "Officials advertise to contact mystery group claiming Medfly releases," Los Angeles Times (10 February 1990):B3; Stephanie Chavez and Richard Simon, "Mystery letter puts a strange twist on latest Medfly crisis," Los Angeles Times (3 December 1988): B1 (Orange County Edition); Robert S. Root-Bernstein, "Infectious terrorism," Atlantic Monthly (May 1991): 44-50; John Johnson, "Invasion of pesky Medfly defies logic, scientists say," Los Angeles Times (30 December 1989): B6; Chris Baker, "Farms targets for terror?; Livestock illness seen as weapons," Washington Times (8 May 2001): B8; See also: Wayne King, "Evidence of tampering found in fruit fly traps," New York Times (28 November 1981) section 1 p 8; Content derived from Biological Case 117, CBRN Incident and Response Database, James Martin Center for Nonproliferation Studies, June 13, 2006 (; Jordan Bonfante, "Medfly madness," Time (January 8, 1990).

10. "Settlers pump sewerage water into Palestinian groves," Palestine Information Network, June 21, 2000; Occurrence of settler Annexation in other cases discussed in report by Michael Ambrosino, "Journey to the occupied lands," Frontline, produced by the Public Broadcasting Company (January, 1993).

11. Sean MacConnell, "Gardai question men with links to animal rights movement," Irish Times (September 27, 2001): 2. See also, Biological Case 1210, Weapons of Mass Destruction and Terrorism Database, Monterey Terrorism Research & Education Project, (

12. "Foot-and-mouth alert launched," Northern Territory News (May 11, 2005); Martin Kay, "Foot-and-mouth damage control," Christchurch Press Company (May 11, 2005); "NZ finds no signs of foot-and-mouth as deadline passes," Australian Associated Press (13 May 2005); Haydon Dewes, "Foot-and-mouth: it's a hoax new letter to Dominion Post," Dominion Post (May 17, 2005); "NZ foot-and-mouth scare confirmed hoax," Xinhua (May 24, 2005); Jon Morgan, "Trace cost 'worth it'," Christchurch Press Company? (May 30, 2005); see also, Biological Case 1806, Weapons of Mass Destruction and Terrorism Database, Monterey Terrorism Research & Education Project, (; for more information on foot-and-mouth disease see (

13. Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare, Vol. I (NY: Humanities Press, 1971), 163 (footnote 27).

14. Stockholm International Peace Research Institute, The Problem of Chemical and Biological Warfare, Vol. I (NY: Humanities Press, 1971), 162-85; National Institute for Science Education, "Agent Orange revisited," Why Files (; "Chemical and biological warfare in Southeast Asia: environmental damage from herbicidal warfare in Vietnam," Calif. Polytechnic San Luis Obispo CBW Page (

15. "Poison is suspected in death of 30 cows on a Muslim farm," New York Times, March 16, 1970, p. 30; James Wooton, "Black Muslims would sell farm to Klan," New York Times, March 17, 1970, p. 32; "Wallace seeking more policemen," New York Times, December 12, 1971, p. 50.

16. "Question of territory under Portuguese authority," UN General Assembly Resolution 2707, 9 (December 14, 1970) web available at: (; Wolf Roder, "Effects of guerilla war in Angola and Mozambique," Antipode 5, no. 2 (May 1973): 14-21; Robert M. Smith, "US suspects Lisbon of using herbicides in Angola," New York Times, December 9, 1970, p. 24.

17. National Foreign Intelligence Board, "Use of toxins and other lethal chemicals in Southeast Asia and Afghanistan," Central Intelligence Agency, Washington D.C. (February 2, 1982): 3-18. Cambodia was renamed Kampuchia in 1976 by the Khmer Rouge government but returned to the name Cambodia in 1989.

18. "Focus," Associated Press (March 26, 1977): AM cycle.

19. National Foreign Intelligence Board, "Use of toxins and other lethal chemicals in Southeast Asia and Afghanistan," Central Intelligence Agency, Washington D.C. (February 2, 1982): 22-24, 30, as well as Annex A p. A2, declassified in 2006, this report outlines primarily evidence of CW use by Soviet forces and possibly their clients beginning as early as May of 1979; Kenneth Alibek with Stephen Handelman, Biohazard (NY: Random House, 1999), 268-269; Kenneth Alibek, "The Soviet Union's anti-agricultural biological weapons," Annals of the New York Academy of Sciences, 894 (1999), 18-19; see also, Jonathan Tucker, "Conflicting evidence revives 'yellow rain' controversy," CNS Research Story of the Week (August 5, 2002) web available at (

20. "The poisoned world-1998," Universiti Sains Malaysia (1998) (

21. Richard P. Jones, "Product recalled in four states; animal feed tainted in act of sabotage," Milwaukee Journal Sentinel, January 4, 1997, p. 1; "MDA investigates possible feed contamination," PR Newswire, January 6, 1997; Nicholas J. Neher, "Food terrorism: the need for a coordinated response--the Wisconsin experience," Wisconsin Department of Agriculture, Trade and Consumer Protection; Gretchen Schuldt, "Man indicted on charges of tainting animal feed Berlin plant contaminated with toxic pesticide in 1996," Milwaukee Journal Sentinel, September 15, 1999, p. 1.

22. Shabatai Zvi (translator), "Israeli settlers destroy 17,000 tons of grapes," Al-Ayyam, October 23, 1997 (

Updated 03/2009

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