By Jeffrey A. Lockwood
Oxford University Press, 2009; 377 pp.
ISBN 9780195333053  price: $27.95 (hardcover)
ISBN 9780199733538; price: $17.95 (paperback)

Jeffrey Lockwood has written a fascinating (if at times depressing) exploration of the role of insects in warfare.  Of all the many researchers of military history, his entomological perspective has no peers.  Likewise, no other entomological works cover this subject matter as comprehensively.

Starting with the dawn of history, Dr. Lockwood reviews the martial use of insects.  The social Hymenoptera, mostly stinging bees and wasps, were widely used in ancient and medieval times to induce panic among enemy soldiers.  Projection of the understandably agitated insects in the direction of the enemy was widespread.

Insect-vectored pathogens have frequently played a major role during the massive human movements and social upheavals associated with war that have occurred throughout history.  However, because insects were not recognized as vectors (until the 20^th century) in the infection and debilitation of troops in the field, wetland habitats rather than insects were implicated as causing diseases such as malaria and yellow fever.  For example, Lockwood describes how the Confederates exploited malarial swamps to decimate and eventually force the withdrawal of McClelland’s Union troops attempting to take Richmond, Virginia during 1862.  Eighty years later, in spite of much better knowledge of pathogen-vector relationships, two million US troops were debilitated by malaria during World War II, particularly in the Pacific theater.

Lockwood chillingly summarizes the most terrifying military applications of insects, which involved the use by the Japanese of fleas with plague and houseflies with cholera to initiate disease outbreaks that killed hundreds of thousands of Chinese civilians during World War II.  Not only were these entomological warfare efforts generously, even lavishly, supported by Japan, but a significant proportion of entomologists and medical personnel were aware of and involved directly in the effort.  The accompanying human experimentation also ranks among the worst of wartime atrocities against innocent civilians.  Particularly shameful from the American perspective is that the leaders of Japan’s insect-based warfare were given immunity from prosecution by the Americans, who apparently hoped that these scientists could aid potential programs in the US.

It has long been recognized that insects could be used against an enemy’s agriculture to weaken the society and force it to spend scarce resources to combat new pests.  But this has been attempted less often than one might expect.  The best-documented example involves France and Germany during World War II, both of which researched the use of Colorado potato beetle, which established in Europe less than three decades earlier.  It is not clear that beetle bombs were ever deployed by either side, but Lockwood details the various allegations that Germany seeded England, and later claims by East Germany and the USSR that the USA was bombarding their potato fields.  Amikäfer (the East German nickname for American beetle) donned a new outfit for propaganda purposes (figure).

During the Cold War, claims of using insects to infest enemy cropland were increasingly difficult to evaluate. Some are notably unconvincing, such as the North Korean claim that springtail vectors were deposited by American-led forces during the Korean conflict.  Clearly, both the US and the USSR had clandestine biological weapons programs that included some entomological components.  It is less clear whether these insect-related tactics were actually ever used.

Insects used as sensors for detecting explosives and other harmful substances are fascinating, and Lockwood details ongoing developments in a semi-technical manner.  Honeybees can be trained to detect and hover over land mines, and parasitoid wasps can be trained to signal the presence of explosives or other target volatile chemicals.  Lessons from the biomechanics of insect movement, particularly flight, are being put to work in the development of ever smaller high-tech drones designed for surveillance and espionage.

Lockwood explores the terrorism scenarios involving offensive uses of insects, which have been discussed in detail by defense planners.  The author argues convincingly that general improvements in public health capacity are more likely to be valuable than are preparations for specific events that may not ever come to pass.  Strengthening public health capacity improves our ability to identify, diagnose, and treat or control new invasive organisms and vector combinations, whatever the source.  The invasion of North America by West Nile virus, a shared threat to animals and humans, revealed shortcomings in US preparedness.  It remains to be seen whether the lessons learned will result in effective protection from introduction of other more serious pathogens, such as Rift Valley Fever. 

Six-legged Soldiers is at its best when recounting histories, even when disputed or clouded by propaganda and politics, as are many recent alleged entomological incidents.  As the author states in his preface, “I’ve consciously chosen to be inclusive in my research, allowing all plausible—even if hard to be believe—claims their place in the story.”  Even the bogus claims are part of the narrative, and the role that entomological aspects play in politics is an important part of their use in war and political disputes. 

Occasionally, the book lapses into melodrama, when the facts alone are usually dramatic enough.  Promotional verbiage which might seem at home on the book jacket is irritating and out of place deep in the text.  While the index is extensive, it has some significant omissions: North Vietnam and other countries are indexed, but not Cuba—the subject of more than an entire chapter on Cuban allegations of pest introductions such as Thrips palmi by the US.  Another minor disappointment is that the images are not always well coordinated with the text.  The lack of color is sometimes a significant drawback, as for the flag-draped beetle pictured here, which is shown in black and white in the book.  These faults notwithstanding, Six-legged Soldiers is well worth the read, a unique and surprisingly varied and lively compendium of mostly sinister uses to which insects have been put in fighting human battles.

Donald C. Weber
USDA-ARS Invasive Insect Biocontrol & Behavior Laboratory
Beltsville, MD 20705
phone 301.504.8369
don.weber@ars.usda.gov
American Entomologist
Vol. 56, No.2, Summer 2010