We’re an interesting species. Let no one say that, for all our faults, a lack of creativity is one of them. We’ll come up with all kinds of ways to hurt each other and mess things up. We’ll even pull in other species for our shenanigans.
The use of insects in warfare dates back to, at least, antiquity. The Greek general Xenophon wrote of an ingenious enemy tactic that knocked out his entire army of 10,000 soldiers. The general’s army had been feasting on honey plundered from the natives of Colchis (present day Western Georgia, along the shore of the Black Sea). Little did they know that these beehives had been intentionally poisoned by the Colchians. These bees had been fed nectar from rhododendron and azalea flowers, containing a toxin known as grayanotoxin. This toxin was then passed through the bees into their honey. Historically, honey containing this toxin was intentionally produced to provide a “kick” to alcoholic drinks in small doses, but the enterprising Colchians saw another use for their “mad honey.” Symptoms of grayanotoxin poisoning include vomiting, dizziness, weariness, loss of coordination, severe muscular failure, paresthesia, and slowing of the heart. Xenophon’s soldiers lived (grayanotoxin poisoning is rarely fatal), but were out of commission for several days. Similar tactics were used against the Romans in their campaign against the Heptakometes.
Bees and wasps have also been used as more direct weapons. The Romans were recorded as launching hives of stinging insects, that would smash open and release a fury of enraged insects. This tactic would be repeated across medieval Europe. Bee hives have been launched at every kind of army or fortification imaginable. “Bee Boles” were often built into castle walls, so that any army breaching them would be surprised by a colony of now homeless, and thus intensely furious, bees. Bee hives were even used in naval battles, with Mediterranean pirates dropping wasps on boarding sailors and Greco-Roman ships launching honey bee colonies at each other. Across the pond, the Mayans had used weaponized hives as far back as 2600 BC. One legend states that the K’ich’e Maya lined the walls of their cities with human dummies stuffed with gourds full of insects. The dummies were dressed in full armor, and when they were smashed open the enraged insects would be unleashed. Enemy soldiers approaching the wall would suddenly find the “guards” falling over the side and exploding into an orgy of stinging pain. These tactics even found use in the 20th century, where the Viet Cong booby-trapped giant honey bee (Apis dorsata) hives to use against the invading American army.
Bees and wasps are perfect for weaponry as they are social and easy to raise in captivity, aggressive and territorial when ired, and an entire colony can fit in a small compact space. But while social insects like bees and wasps were an obvious choice of weapon, they aren’t the only arthropods used in this manner. Horsefly bombs and dummies similar to the bee variations above were recorded in Mesoamerica. During the Roman-Parthian Wars, and particularly the sieges of Septimus Severus in 198 AD, the Iraq city of Hatra used clay bombs filled with scorpions to successfully drive away the Roman armies. In Uzbekistan, pit traps were filled with assassin bugs. These pit traps were more commonly used as torture devices, most famously when the Emir of Bukhara sentenced two British officers to such a bug-pit for months before finally beheading them in a public ceremony.
One of the most sinister modern examples of weaponized insects comes from Japan’s covert biological warfare research and development unit, Unit 731. Officially known as the “Epidemic Prevention and Water Purification Department of the Kwantung Army” Unit 731 was in fact a place of horrific human experimentation and torture. In one plan, developed during WWII by Surgeon General Shiro Ishii, bombs filled with bubonic plague-carrying fleas were dropped over the Chinese cities of Ningbo and Changde. It is estimated that 200,000 Chinese people died as a result of the plague spread. It was successful enough that the Japanese military planned an operation called “Cherry Blossoms and Night” which would have released more fleas across California, but the plan was never enacted. A similar plague-carrying-flea plot was planned during the Battle of Bataan in March 1942, however American forces surrendered before the fleas were released. After the war, the US agreed to grant immunity and cover up the project (along with many other ghastly medical experiments) in exchange for access to the data. Unit 731 first came to public light during the mid 1990s.
The Japanese were not the only nationality to research weaponizing insects during WWII. Canada was one of the pioneering powers of vector-borne warfare. Kingston’s Queen’s University’s Defense Research laboratory looked into the possibility of mosquitoes, flies and fleas as weapons. Both France and Germany had researched the possibility of using insects such as the Colorado potato beetle (Lepinotarsa decemlineata) to devastate enemy food supplies. In Germany, a test of the potato beetle program backfired, resulting in an infestation of 54,000 beetles. After WWII ended, the United States began using the remains of Japan’s Unit 731 in their Cold War battles. A British study carried out in 1989 found strong evidence that the US used the Japanese biological weapons during the Korean War. While most of the weapons the US may have used were toxins extracted from wheat and rice mold, entomological weapons may have been used as well. There is also evidence against the charge that the US used biological, including insect, weapons in Korea. A cache of documents released in 1998 by the Cold War International History Poject shows evidence that the Soviet and Chinese claims of the US using insects in Korea was an elaborate disinformation campaign. Of course, in that case the IDEA of weaponized insects was then weaponized by the other side, so I say either way it counts.
Regardless of whether the US truly did use insects (or any other biological weapons) in Korea, insects were a big part of Cold War research. The Soviet Union developed techniques to spread pathogens through ticks, while the US did the same with mosquitoes. Both powers used the existence of entomological weapons as part of their Cold War threats, such the Soviet Union announcing they had built an automated insect breeding facility, pumping out millions of disease-filled insect soldiers each day. Meanwhile, the US tested their weapons on their own populace. 1955’s Operation Big Buzz dropped 300,000 yellow fever mosquitoes (Aedes aegypti) over the state of Georgia. These mosquitoes were not infected, but still, gross and creepy. Several other tests are known of, such as Operation Drop Kick and Operation May Day.
The US has also, more recently, been researching weaponized caterpillars. For decades the US government had been dropping pesticides over South America as part of the War on Drugs. The long term effects of this was mainly the evolution of marijuana and coca plants that are completely resistant to pesticides. As early as 1990, the US has funded programs designed to drop ravenous caterpillars on farms instead. By far the most impressive caterpillar research the US military has carried out is the Hybrid Insect Micro-Electric-Mechanical System (HI-MES) which implants computer chips in caterpillars. When the caterpillar undergoes metamorphosis into a moth or butterfly (just an aside, technically all butterflies are moths), the computer chip will allow scientists to remotely control the flight path of the insects. One day this could lead to spy-moths, or butterfly scouts transmitting data over wifi without being detected.
If these stories of plague-flea-bombs, potato beetle terrorism and cyborg moths sound like completely unfeasible science fiction scenarios you’ll never have to worry about, be very thankful that most people today with the power to invest in bug weapons think the same thing. Invasive arthropods may be one of the most sinister weapons you can unleash on a country. In the late 1980s, an eco-terror group known as The Breeders claimed responsibility for releasing Mediterranean fruit flies (Ceratitis capitata) into California. While they cannot be the only source for the flies, the evidence shows SOMEONE helped make the infestation as bad as it was. The medfly infestation cost California billions of dollars in crops and manpower. The flies reproduced faster than they could be sprayed, leading to the government switching to releasing sterile male flies as an alternative in the 90s. Even so, the invasive flies weren’t eradicated until 2008. Today the sight of a possible medfly will shut a port down and spark a frenzy of investigations. A well-timed invasive species would be almost impossible to detect and could disrupt or even destroy an economy, to say nothing of the damage to the region’s ecology and biodiversity.
Actually you could very well argue that colonialism has ALREADY weaponized invasive species, as I’ll go into in more detail in my next ecology post. Colonial powers have intentionally released animals and plants across the world, not only destroying local ecology but also destroying indigenous food supplies, medicine, even music and religion! Tune in next time to learn how people have used trout to kill cultures.
If you want to read more cool stories about gross things we’ve done to bugs and gross things bugs have done to us, I can’t recommend Amy Stewart’s Wicked Bugs enough.