No amount of money can compensate for millions of dead insect species. Money can’t buy me love, pollination, honey, food, and complex, dynamic relationships among insects, plants, soil, greenhouse gases. When insect species disappear, the magical mystery Magicicada musical will be silenced, and the trees, turtles, fish and birds will suffer as they lose that periodic extravagance of fertilizer and feed. The insectivorous birds will disappear. Flowers will bloom once and then wrinkle and waste away.
No amount of money can compensate for millions of dead insect species. Money can’t buy me love, pollination, honey, food, and complex, dynamic relationships among insects, plants, soil, greenhouse gases. When insect species disappear, the magical mystery Magicicada musical will be silenced, and the trees, turtles, fish and birds will suffer as they lose that periodic extravagance of fertilizer and feed. The insectivorous birds will disappear. Flowers will bloom once and then wrinkle and waste away. Once honey bees are gone, or monarch butterflies, or dung beetles, shareholder profits will not bring them back. In the pesticide and fertilizer whorehouses, money can buy a one-night stand, a few seasons of corn or soy or canola. Pesticides provide temporary, short-term, transitional satisfaction for managing our culinary desires.
Environmental engineer M. Premalatha, in a 2011 scholarly review titled “Energy-efficient food production to reduce global warming and ecodegradation: The use of edible insects,” commented that “The supreme irony is that all over the world monies worth billions of rupees are spent every year to save crops that contain no more than 14% of plant protein by killing another food source (insects) that may contain up to 75% of high quality animal protein.” The global agri-food system — the economy in general — however, does not run on irony.
How can we begin to reconcile, in practice, and not just in our heads and hearts, our conflicting experience with, and mixed feelings about, bugs?
People already eat locusts so that, at first glance, one strategy to control insect pests without using insecticides would be to eat them. It is a crude strategy, and has been tried. With a few exceptions, eating insect pests has not been very successful in controlling them. Still, in a search for non-toxic strategies to manage human-insect-food relationships, it is worth looking at those exceptions.
In Thailand, in the 1970s, there was an outbreak of patanga locust (Patanga succincta) in maize. When aerial spraying of insecticide failed, the government promoted eating them, and even promulgated recipes. Today, deep-fried patanga is a popular, and the species isn’t considered a serious pest. There are even farmers now who grow maize to feed the locusts, which bring a better price. Food? Pest? Yes. And yes. And most assuredly 50 years of exposure to eating locusts is better for one’s health than 50 years of exposure to pesticides, no matter how low the residues.
About 80 species of grasshoppers and locusts are eaten worldwide. Although there is a lot of variation in their nutrient content, most locusts, with about 60% protein and 13% fat (dry weight), are right up there with cows and cockroaches as excellent sources of human nutrition. Nor is this, for many people, a “novel” food source. There is a long history of humans around the world eating locusts and grasshoppers. Studies of human feces at Lakeside Cave in Utah indicate that, at various times going back 4,500 years, hunter-gatherers near the Great Salt Lake sometimes ate locusts and grasshoppers.
Millions of grasshoppers and/or locusts periodically crash-landed into the waters of the Great Salt Lake. Washed up on the shore, naturally salted and sun-dried, they became a grand buffet. More recent enthographic and ethnohistorical studies revealed that grasshoppers and crickets have been part of the diets of some indigenous people in that area well into the late 19th and early 20th centuries.
So when I read of the locust plagues that devastated large parts of Madagascar in 2012 and several years following, my mind drifted to the possibilities of fall-season soups and mock-raisin breads. I wondered whether people could just eat the locusts. Why not? Well, they could, but it’s not so simple. The voracious locusts swarms destroyed rice fields and pastures, causing hunger and threatening the food security of 13 million people. Making a bad situation even worse, the plague hit the news just before Passover, and hence, in the Judeo-Christian-Islamic imagination of western societies, resonated with biblical implications. It was both a devastating plague and a public relations nightmare. International and government agencies sprayed insecticides to manage the hungry pests, thereby contaminating a possible alternative food supply. Some children, though, were catching them by hand or in mosquito nets, drowning them, and roasting or frying them. Other farmers explained that the locusts might be a good source of food, but they did not keep as well in storage as rice. They rotted. There was no generic, one-size-fits-all response to the locusts. To address this would require facing the challenge of stopping the plague and, at the same time, developing new ways to harvest, store, and preserve the locusts for food. Given the cultural dynamics of post-colonial societies, and the sense of embarrassment that may accompany eating “bugs” in front of Europeans, this would require a lot of courage and engagement with people where they lived, talking to farmers, elders, cooks, children, and some major rethinking of strategies and appropriate, innovative technologies.
In Lockwood’s description of the American locust plagues, he notes that some farmers were initially happy that their poultry were stuffing themselves on locusts. This happiness disappeared when their chickens and turkeys gorged themselves to death. The farmers managed this lethal feasting by giving the birds a bit of grain before turning them loose on the locusts. But still, there were so many! Too many! More problematically, the farmers later reported that the flesh and eggs of these poultry were inedible, exuding a pungent, oily odour. Others lamented the great stench of rotting carcasses along the lakeshore and in ponds, streams, and wells. Again, one of the issues that this raises is that of how best to harvest and preserve sudden windfalls of food, which is an intense, special case of the issues faced by all human settlements for more than 10,000 years. It has been a driving force behind the long histories of fermentation, salting, sugaring, refrigeration, drying, vacuum-packing, and, more recently, genetic modification of fresh produce to extend shelf-life. I have the sense that, were we to take insects seriously as food, we could solve the storage and preservation problems as we have for grains, breads, dairy products and fresh produce. In pre-Euro-invasion America, some indigenous groups came up with the ingenious idea of making a “desert fruitcake” of insects, pine nuts and berries, mashed together and sun-dried. The Honey Lake Paiute prepared a soup of dried crickets and locusts. The Japanese have produced hornet pickles and alcoholic drinks, Europe has its history of mead, and a group in the United States now testing beer fermented with yeasts carried by wasps. The possibilities may not be endless, but the list of preservation methods is most assuredly long.
In Mexico, some species of grasshoppers are considered serious pests of corn, beans, alfalfa, squash and broad beans. Since the 1980s, many farmers have tried to control them through spraying organophosphate insecticides (mostly parathion and malathion, both of which are considered relatively nontoxic to people). The grasshoppers are also recognized as a source of food, an Aztec tradition going back at least 500 years. Even today, between May and September, harvesters from Santa Marıa Zacatepec (Puebla) head out into the fields before dawn; they are able to capture 50 to 70 kilograms of grasshoppers per week, and 75 to 100 tons per year. The annual sale of this grasshopper harvest brings in $3000 USD per family; for 6 months, this provides the main source of income for these people.
This is all well and good for the harvesters, but what about the farmers who want to control the pests? Two researchers from the Universidad Nacional Autonoma de Mexico decided to find out. Over two years in the first decade of this century, Rene Cerritos and Zeno Cano-Santana monitored grasshopper infestations in field plots that had been sprayed, and compared them to plots where grasshoppers were harvested manually. Although the lowest grasshopper infestation rates were in fields that were treated with insecticides, the researchers concluded that mechanical control still reduced the infestation to manageable levels, saved the farmers $150 USD annual costs for insecticides, brought extra income into the village, and reduced risks associated with water and soil contamination, and eliminated negative effects on non-target species. Mechanical harvesting had the added social advantage that it required farmers and harvesters to talk to each other and coordinate their activities. The World Bank used to call this social capital, and, in a region where social breakdown is a problem, this is not a trivial advantage.
In the long run, we need these kinds of alternative commitments; complex eco-social systems are more resilient at resisting pest infestations, but nurturing those will take some serious rethinking of how we live. In the meantime, can we find ways of living, however uneasily, together with insects? Although the Soviet Union and the United States never fought their ideologically-based wars directly, the bloody battles in Guatemala, Nicaragua, Honduras, Uruguay, Angola, Mozambique, Cambodia and Vietnam were surrogates. Non-Russians and non-Americans died in large numbers to keep alive the Russian and American dreams of world domination. That is how empires work. Similarly, since Rachel Carson’s documentation of the unintended negative consequences of pesticides entered the public discourse, the war against pestiferous insects has not stopped, merely shifted. The war metaphors, having informed medical practice, are now, in the language of surgical strikes, coming full circle, and creating a mythology that offers at least the illusion of killing no innocent bystanders.
One of the most widely known and practiced strategies to control insect populations with minimal collateral damage is what has been called companion planting (by friendly gardeners) and intercropping (by more serious business farmers). More than 1500 species of plants have some insecticidal properties, but even non-insecticidal plants can provide some field wide resistance to the spread of pests. Another strategy is to bringing in other insects that prey on or parasitize the ones you don’t want (the pest-control equivalent of surrogate wars). More recently the use of pheromones, genetic modification and playing distressing, infuriating music have been tried. I’ll only talk about a few of them to make the point that, even if some agribusiness leaders support the contestable and doubtful assertion that pesticides are necessary to feed the world, we have options other than starvation and revolution.
Farming of course predates industrial pesticides by more than a few millennia. A 2013 report in the National Academy of Science (USA) suggests that agriculture in China goes back more than 20,000 years. Citrus trees have probably been cultivated for a couple of millennia. Mandarin oranges, which as children in the winterlands of western Canada we called Japanese oranges, originally spread from their birthplace in north India or southern China across Southeast Asia, and from there to Europe and around the world.
Having cultivated citrus trees for thousands of years in a country that was the birthplace of entomology, it is no surprise that Chinese farmers had experience with pests and non-toxic pest controls. They were aware, for instance, that the citrus stinkbug, citrus leaf-miner, leaf-feeding caterpillars, and aphids could — and would — attack their lemon, orange, pomelo and tangerine trees. Not having access to malathion, acetamiprid, cyhexatin+tetradifon, methidathion, spinosad and other modern weapons of the war on insects, they tried working with nature, rather than running immediately into battle. Perhaps they had read the advice of Sun Tsu in The Art of War, written many centuries BCE: “The supreme art of war is to subdue the enemy without fighting.”
Chinese farmers are credited with instigating the first documented use of insects to control other insects. About 1700 years ago, they discovered that a strain of weaver ants — yellow citrus ants (Oecophylla smaragdina Fabr) — would eat a wide variety of plant-eating pests. In the early years, they tracked down and collected nests from the wild; later (about 985 CE), using fat as bait, they trapped the ants in hog and sheep bladders. After about 1600, the farmers discovered that, if they constructed bamboo bridges between the trees, the ants would occupy the whole orchard even if only a few of the trees were seeded. Winter was a challenge, as the ants had trouble surviving the cold, so the farmers started collecting the ants in the fall and feeding them citrus fruits until the warm, spring days returned. Finally, some observant farmers noticed that the thicker foliage of pomelo trees provide better protection — a sanctuary if you will — for the ants. If the farmers have mixed groves of oranges and pomelos, and build bamboo bridges among them, the ant nests in the pomelo trees serve as an annual, renewable source of insect control.
In “Six-legged Livestock,” a 2013 FAO report on edible insect farming, collecting and marketing in Thailand, authors noted that weaver ants are also used for pest control in mango orchards. Some farmers maintain their own nests, but finding queens and good sanctuary trees is a challenge, so that often the ants are foraged. The farmers create ant highways between trees with rattan or cane ropes, which the ants — who are remarkable engineers — then use to move to new sites, where they build new nests from larval silk. Weaver ants are celebrated in songs and dances in the north-eastern Thailand, where their eggs, pupae and adults are incorporated into salads and omelettes. Eating other pest control products, such as insecticides, is not generally recommended.
European and North American agriculture expanded most rapidly during the period when industrial pesticides were widely available and only minimally controversial. Non-bug-insect-eating cultures have become addicted to these toxins, and have aggressively marketed their drug habits abroad. Now, after decades of pesticide addiction, many agriculturalists in China, Europe and worldwide are rediscovering “beneficial” insects.
Generally, the less toxic and more ecologically sustainable approaches to pest control — that is, those most compatible with entomophagy — require much more sophisticated agricultural practices and knowledge of ecology than using insecticides. In a 2016 report on the control of cochineal pests in prickly pear plantations in central Mexico, the researchers concluded that six different species of natural predators did keep the pest populations in check, as farmers had reported. They cautioned, however, that such “autonomous biological control” methods depended on agroecosystems with structural complexity and species diversity.
Often, just to hedge their bets in the face of scaremongering by pesticide manufacturing companies, 21st century farmers use a combination of natural predators and pesticides. So-called Integrated Pest Management (IPM) considers and uses all forms of insect control, and then targets insecticides at specific times in the growth cycle of crops. The medical-war analogy for this would be surgical strikes. Many of the IPM methods use natural enemies of insects, such as bacteria or protozoa. If seeded into standing water, different strains of Bacillus thuringiensus for instance, kill mosquitoes and black flies. Bacillus popilliae kills Japanese beetles.
Although René Antoine Ferchault de Réaumur recommended the release of lacewings into greenhouses to eat aphids as early as the 18th century, it is only in the past few decades that biological controls in non-insect-eating agriculturalists have gained some traction. Hundreds of species (and millions of individuals) of insects, including the infamous, tiny parasitoid wasps, which are not interested in stinging people, are now raised by the millions around the world. These insects are raised specifically for release into greenhouses and onto field crops. Parasitic wasps can find the underground pupae of corn earworms and army worms and lay their eggs on or in them; the wasp larvae then eat the worms. Commercial applications for the use of three wasps, Diapetimorpha introita (which attacks beet armyworms), Cryptus albitarsus, which attacks tobacco budworm, and Ichneumon promissorius, which attacks 10 other insects considered pests in the US, are currently under investigation. By 2000, there were more than sixty-five companies worldwide producing these “natural enemies,” many of them for the greenhouse market.
Among North American farmers and gardeners, ladybird beetles were the test case that proved the value of biological controls. They also demonstrated the importance of fine distinctions. Ladybugs (actually Coccinellidae, a family of beetles belonging to the suborder Polyphaga) have been both celebrated and misunderstood. The celebration is evident in the name, which is an abbreviation of Our Lady’s Bird. She is said to have earned this name when medieval farmers, plagued by sap-sucking aphids on their crops, prayed to the Virgin Mary for help and were rewarded by visitations from these aphid-eating beetles. Of some 250 names for these beetles, in 50 languages, 63 include some variation of Virgin and 52 some variation of God. May Berenbaum also notes less exalted names such as “Cowlady” and “Bishop is burning,” while Waldbauer cites the Hebrew name that means “creature of Rabbi Moses.”
The misunderstanding part of this story occurred because someone, thinking that Mother Mary had things in hand, wasn’t being sufficiently mindful. In the late 1800s, the California citrus industry was being attacked by a cottony cushion scale (Icerya purchasi), a pest that had inadvertently been imported from Australia. Entomologist C.V. Riley, chief entomologist at the United States Department of Agriculture (USDA), who was an important player in the battles against locust plagues in the US, and in designing phylloxera control programs in European vineyards, had an idea as to what might work to control the scale insects. USDA staff were not allowed to travel, so he sent Albert Koebele to Australia. Koebele brought back the ladybug beetle Rodolia cardinalis, as well as a parasitic fly, Cryptochaetus icerya, which were released into the orchards. The subsequent success of bringing Icerya purchasi under control was attributed to the ladybugs, and soon farmers from all over the country wanted some. This success, however, coupled with the lack of entomological knowledge, has created misunderstandings and confusion among Just Plain Folks like me. A ladybug is not a ladybug is not a ladybug, so that importing generic Virgins into your garden may or may not work, depending on whether they prefer beach weather or a bracing, yet temperate, cold, and how they imagine their ideal mates But mostly, it depends on their food preferences. There are some 6000 species of ladybug beetle worldwide, many with different eating preferences. Members of the subfamily Epilachninae, for instance, feed on plants such as squash. Gardeners, in trying to save their squash from the lovely ladies, have tried to control them using parasitoid wasps, which are now also being used to control scale infestations.
The downside of importing natural enemies into new territories is that the immigrant predators may develop tastes for other foods; as in any war, killing friends and innocent civilians — so-called “collateral damage” — is a major problem in the war on insects.
Breeding and releasing sterile male and/or sterile females is a technique that has shown greater promise when used by entomologists to control pests and than by political leaders to control human populations. Using variations of this strategy, insects (usually males) are sterilized by radiation and released into the population of alleged insect pests. Like most non-pesticide methods, this requires an understanding of the breeding behaviour and ecology of the insects, as well as some pretty clear ecological boundaries. This technique works best on isolated populations, such as those on islands, or insects that are fussy about the species they feed on, and in insect species in which the females only breed once, but the males are more promiscuous. One of the test cases for the sterile-male approach was the eradication of the screw-worm fly (Cochliomyia hominivorax) from parts of North America. It’s also been used to control a few species of fruit fly. Japan successfully eliminated melon flies Bactrocera cucurbitae from several of its islands, between 1971 and 1993, by releasing tens of millions of sterile males.
In a technique that I suspect some human females might envy, many species of beetle, wasp, and butterfly females carry around bacteria that are transmitted to males during breeding. The bacteria kill the males; the females get to keep the babies and pass on the genes, but they don’t need to worry about the males going off and sharing bodily fluids with other females. Entomologists have yet to determine the mechanisms for this selective killing, but, if discovered, these could be used as part of a pest control program.
A variation of the sterile insect technique was reported by US researchers in 2012 and again in 2015. Using CRISPR/Cas9, a “cut-and-paste” technique to alter DNA, they developed a strain of mosquitoes that is completely resistant to infection with Plasmodium falciparum (the parasite that causes malaria) but is otherwise, as far as anyone can tell, completely healthy and able to breed. It seems to be more effective in males than females. When they release their “brand” (their word, not mine) into the wild, they expect that the altered mosquitoes will completely interrupt malaria transmission in the areas where they are released.
I am not a big fan of lab-based genetic modifications, since they lack the contextual complexity, temporal reality checks and scanning for unintended consequences that one sees with slower moving breeding programs. What might be some unintended consequences? Historically, similar diseasecontrol programs for blow flies and tsetse flies have had some success by releasing sterile males into insect populations. Over time, fewer babies are born, and the population of insects may be reduced or become extinct, at least within defined regions such as island or valleys. These new proposals are different, however. The modified mosquitoes are still there, reproducing, but can’t be infected. What if the parasite or virus is a natural limiting factor in the mosquito populations, as diseases in wildlife often are? Will removing the parasite increase the reproductive success — and population size — of the mosquitoes? With a larger population size, will they pick up other viruses or parasites to which they are still vulnerable and carry them? Having said that, if this work is successful and malaria is eradicated, I would have to be a pretty miserable curmudgeon to not celebrate.
In the meantime, researchers in Ethiopia, which is not an island and where the hi-tech branded solution would therefore be just another neo-colonial white elephant, have found that hanging a caged chicken near your bed significantly reduces the mosquito populations nearby. Apparently the mosquitoes don’t like the smell. Not a magic bullet perhaps, but disease prevention and dinner in the same package sounds pretty good to me.
Some suggested newer control methods are both imaginative and even more ethically problematic. Southern pine beetles and western pine beetles like similar trees, but never inhabit the same individual tree. David Dunn, the musician and composer who studied the acoustic ecology of insects, wondered what would happen if he played southern pine beetle sounds to western pine beetles. In 1989, a 10-day blast of Alice Cooper, Van Halen, Styx, Kiss, Ratt, and Judas Priest drove Panamanian leader Manuel Noriega from his place of asylum at the Vatican embassy. So what would happen if you played annoying music to beetles? What happened was that the western males mated — and then tore the females to pieces. Dunn has explored this further, composing non-linear, chaotic electronic music, and then playing it to insect audiences. “Dunn plays such sounds back to the beetles,” says David Rothenberg, “and they tear each other to shreds. What more convincing reaction to one’s music could one hope for than that?” Note to self: avoid concerts by David Dunn. To my knowledge, insecticidal music has yet to be tried on a larger scale.
Dunn’s bug-aggravating music is a reminder that all the ways in which insects relate to each other and with the world around them — sound, sight, scent, pheromones, magnetism — offer opportunities for humans to converse with them, to harangue them, to manage our interactions in such a way as to minimize the damage. Rather than weapons of war against insects, these are languages to encourage argument, conversation and the live-and-let-live attitude which Jeff Lockwood calls entomapatheia. Engaging in these multi-lingual conversations and arguments with insects helps us to better understand how other species see us, and therefore enlarges our sense of what it means to be human. These conversations also provide an opening and a context for negotiating our way into a convivial future.