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Insects of war, terror and torture

Nature volume 456, pages 3637 (06 November 2008) | Download Citation


Whether natural or intentional, the security threats posed by arthropods — from assassin bugs to disease-carrying pests — should be of concern to us all, explains Kenneth J. Linthicum.

Six-Legged Soldiers: Using Insects as Weapons of War


Oxford University Press: 2008. 400 pp. £14.99, $27.95 (hbk) 9780195333053

From plagues to malaria transmission, insects and other arthropods have threatened military and civilian populations throughout human history. The success or failure of military campaigns has frequently been determined by correctly anticipating the risks of diseases borne by insects and other vectors, and then mitigating against them. Recognizing this, the world's armed forces employ a large cadre of scientists with expertise in entomology or preventive medicine.

Tiny terrorists: the assassin bug (above) and the Colorado potato beetle, or 'Amikäfer' (left), touted as a US cold-war weapon in 1950s East Germany. Image: DEUTSCHES HISTORISCHES MUSEUM, BERLIN; THÜRINGER KLOSSMUSEUM; M. & P. FOGDEN/CORBIS

Six-Legged Soldiers describes many potential or actual uses of insects as offensive weapons during the past 100,000 years, with an emphasis on the past 300 years. Entomologist Jeffrey Lockwood describes how stinging and highly toxic insects and other arthropods have been used to cause pain and suffering to foes — from the use of bees and hornets by early humans to attack enemies, to the assassin bugs used by an Uzbek emir for torture in the early 1800s.

It is often difficult to determine whether an insect-borne threat is a natural occurrence or an intentional act. As an example, Lockwood explains how six of the ten plagues that struck Egypt, as described in the Old Testament book of Exodus, may have been caused by natural phenomena involving insects. As natural vectors of disease, insects affected many wars in recorded history, including Napoleon's campaigns, the American Civil War — in which two-thirds of the 500,000 soldiers who died were killed by diseases such as malaria and yellow fever — and the First World War.

In the Second World War, insects were developed as biological weapons; the infamous Japanese Unit 731 programme had plans to produce 5 billion plague-infected fleas per year. During the cold war there was an unprecedented level of research and development into using insects as biological warfare agents. Lockwood discusses accusations and activities concerning Korea, Vietnam, Cuba, the Soviet Union and the United States. He ends with a look to the future uses of insects in warfare, including, potentially, agroterrorism, bioterrorism, insects as sentinels and detectors, and insect cyborgs.

Biological warfare is typically developed as clandestine operations. Although it may be used in propaganda campaigns to create fear among the enemy, it is poorly documented. The secret nature of this morally repugnant form of warfare is maintained to eliminate evidence that could be used by prosecutors in future international war-crimes tribunals. Lockwood relies on personal interviews and declassified and previously published documents, and he presents a wide array of accounts. He is carefully circumspect, realizing that some of the accounts may be untrue or partially true, and he qualifies his statements accordingly.

Lockwood takes care to describe accurately the scientific nomenclature of the insect taxa he is discussing, whether it be the mosquito vector of dengue fever, Aedes aegypti; a putative tick vector of haemorrhagic fever in the family Ixodidae; or the Mediterranean fruitfly Ceratitis capitata.

Six-Legged Soldiers highlights the vulnerability of the United States and other Western nations to terrorist attacks. It draws from the 1999 introduction of West Nile virus into the United States, where the disease, of unknown origin, spread from New York to California in five years. A potentially greater threat is posed to human and animal health by Rift Valley fever, another mosquito-borne disease of sub-Saharan Africa. Lockwood states that “the prognosis for curtailing Rift Valley fever by suppressing its vectors is poor”, and implies that US public-health and agricultural communities are not addressing the threat. However, he fails to recognize the efforts that are underway. Outbreaks in Africa are being predicted by scientists at the US Department of Defense, NASA and the US Department of Agriculture, allowing international bodies and individual nations to enhance global vigilance. US federal, state and local agencies are developing research agendas and formulating control strategies for vectors of Rift Valley fever.

Lockwood describes a history of collaborations in the United States between the defence department and the Department of Agriculture to develop insect-based biological weapons extending back to the Second World War. Yet he does not mention other significant collaborative efforts to protect military and civilian populations from insect bites and disease transmission, such as the development in the late 1940s of the most effective and widely used insect repellent, DEET, and the Deployed War-Fighter Protection (DWFP) programme started in 2004 to produce new insect repellents and control products and technologies to protect deployed troops. The DWFP programme has produced more than 60 peer-reviewed scientific publications including the application of RNA interference technology to potentially develop a new class of insecticide that is safe to non-targeted species. Given the paucity of effective vector-borne disease mitigation tools, the products developed in the DWFP programme will directly reduce disease.

Six-Legged Soldiers is an excellent account of the effect that arthropod-borne diseases have had on warfare. The discussions of how we are prepared, or not, for future threats from military operations, accidental introductions or bioterrorist events are pessimistic. The book highlights the need for further research to prevent, detect and mitigate vector-borne disease introductions, and to prevent globalization of entomological threats. This book will inspire readers to understand those threats and prepare new methods to combat them.

Author information


  1. Kenneth J. Linthicum is director of the USDA Agricultural Research Service, Center for Medical, Agricultural, and Veterinary Entomology, Gainesville, Florida 32608, USA.

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