Eat the Beetles!: An Exploration into Our Conflicted Relationship with Insects

by David Waltner-Toews

  Chinese farmers are credited with instigating the first documented use of insects to control other insects. About 1,700 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 CE, 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 provided better protection — a sanctuary, if you will — for the ants. If the farmers had mixed groves of oranges and pomelos, and built bamboo bridges among them, the ants would nest in the pomelo trees and 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, the authors noted that weaver ants were 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 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 northeastern Thailand, where their eggs, pupae, and adults are incorporated into salads and omelets. (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-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.73

  Often, just to hedge their bets in the face of scaremongering by pesticide manufacturing companies, twenty-first-century farmers use a combination of natural predators and pesticides. Integrated Pest Management (IPM) considers and uses all forms of insect control, employing insecticides only 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, for example, different strains of Bacillus thuringiensus will kill mosquitoes and black flies, and Bacillus popilliae will kill Japanese beetles.

  Although René Antoine Ferchault de Réaumur recommended the release of lacewings into greenhouses to eat aphids as early as the eighteenth century, it is only in the past few decades that biological controls have gained some traction among non-insect-eating agriculturalists. 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, specifically for release into greenhouses and onto field crops. Parasitic wasps can find the underground pupae of corn earworms and armyworms and lay their eggs on or in them; the wasp larvae then eat the worms. Commercial applications for the use of three species of wasp — Diapetimorpha introita, which attacks beet armyworms, Cryptus albitarsus, which attacks tobacco budworms, and Ichneumon promissorius, which attacks ten other insects considered pests in the United States — 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. Ladybird beetles, or ladybugs as they are known in North America,74 have been both celebrated and misunderstood. The celebration is evident in the name, which is an abbreviation of Our Lady’s Bird. These beetles are 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 insects. 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 given to these beetles, such as “Cowlady” or “Bishop is burning,” while Waldbauer cites their Hebrew name, which means “creature of Rabbi Moses.”

  The misunderstanding related to the importance of fine distinctions. Some ladybug beetle enthusiasts, thinking that Mother Mary had things in hand, weren’t sufficiently mindful. In the late 1800s, the California citrus industry was being attacked by the cottony cushion scale (Icerya purchasi), a pest that had inadvertently been imported from Australia. Charles Valentine Riley, chief entomologist of the US Department of Agriculture (USDA), who had been an important player in the battles against locust plagues in the United States and in designing phylloxera control programs in European vineyards, had an idea as to what might work to control the scale insects. Circumventing travel restrictions for USDA employees, Riley had his assistant Albert Koebele designated as a US State Department representative at an international exposition in Melbourne, Australia. In 1888, Koebele sent back hundreds of live ladybug beetles (Rodolia cardinalis), as well as a parasitic fly, Cryptochaetus icerya, which were released into the orchards. The subsequent success of bringing cottony cushion scale under control was attributed to the imported beetles, 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 six thousand 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 insects is a technique that has shown greater promise when used by entomologists to control pests than when used 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 nonpesticide methods, this strategy requires an understanding of the breeding behavior 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, insects that are fussy about the species they feed on, and insect species in which the females only breed once but the males are more promiscuous. O
ne of the test cases for the sterile-male approach was the eradication of the screw-worm fly (Cochliomyia hominivorax) from parts of North America. The approach has also been used to control a few species of fruit fly. Japan successfully eliminated the 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 humans might envy, the females of many species of beetle, wasp, and butterfly 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, they might 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 for altering DNA, they developed a strain of mosquitoes completely resistant to infection with Plasmodium falciparum (the parasite that causes malaria) but otherwise, as far as anyone could tell, completely healthy and able to breed. These scientists expect that when they release their “brand” (their word, not mine) into the wild, 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 of these unintended consequences? Historically, similar disease-control 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 even disappear, at least within defined regions such as islands 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 voiced these worries, if this work is successful and malaria is eradicated, I would have to be a pretty miserable curmudgeon not to celebrate.

  In the meantime, researchers in Ethiopia, which is not an island, and where the high-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 newer suggested control methods are both imaginative and even more ethically problematic. Southern pine beetles and western pine beetles like similar trees, but the two species never inhabit the same individual tree. David Dunn, a musician and composer who has studied the acoustic ecology of insects, wondered what would happen if he played southern pine beetle sounds to western pine beetles. After all, in 1989, a ten-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 concept further, composing nonlinear, 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 that Jeff Lockwood calls entomapatheia.75

  PART V.

  GOT TO GET YOU INTO MY LIFE

  If we in the non-insect-eating world wanted to get bugs accepted as a crunchy lunch, how would we go about doing that? Are they already here, and we just don’t notice them, creeping onto our plates through the back doors, kitchen windows, and animal barns? Can we learn from the many non-European societies who have eaten insects for millennia? Let us go deeper into this new continent of entomophagy. Let us look more carefully at the ways in which insects can be food, feed, and perhaps even — can our new, kaleidoscopic eyes see this? — friends.

  LEAVING THE WEST BEHIND?

  Entomophagy in Transition in

  Non-Western Cultures

  Those bamboo worms really knock me out.

  The first time I knowingly and deliberately ate insects, in Kunming, China, it was a simple act of cultural deference. If you are a guest in another country, and they offer you bugs to eat, it is rude to decline the offer.

  In January of 2010, Xu Jianchu, an ethnobotanist working with China’s minority peoples, hosted a richly diverse feast for our working group on the ecological and social interactions that lead to the emergence of new diseases. The revolving table seemed to me like a Tibetan Wheel of Life — delicate, colorful, carefully arranged chaos. There, among the stir-fried, kebabed, and spiced-up flowers, roots, pods, leaves, lobster sushi, chicken, and pork, was a basket of crisp, deep-fried worms. Omphisa fuscidentalis, the bamboo borer, is a moth of the Crambidae family, but in the kitchen and on the plate, the larvae are simply called “bamboo worms.” Struggling to overcome my Canadian squeamishness in the name of cross-cultural collaboration, I tried some. They tasted to me like french fries, but with small, crunchy heads. Xu, watching me with a smile, said he preferred them not quite as thoroughly fried, a little softer and juicier, and then regaled us with tales of all the foods he had eaten, which seemed to cover just about anything that had once wiggled or crept on the earth, or flown in the air, or swum in waters brackish or sweet. I neglected to ask Xu about the possible destructiveness of traditional foraging for bamboo and the viability of rearing worms in bamboo plantations.

  There are a lot of other things I would still like to ask Xu Jianchu, perhaps over a cup of insect tea, made from the feces of vegetarian insects. A 2013 scholarly review paper suggested that traditional Chinese insect tea lowered blood lipids and had antihypertensive and hypoglycemic effects.76 I am thinking now that I must go back to Yunnan and ask Jianchu about the ten species of cocoons eaten by the Wa people, and what the Tibetans do with Cordyceps, a caterpillar whose body is taken over by a fungus.

  One could spend many lifetimes exploring all the other bugs eaten by minority and indigenous people around the world, who could teach all of us non-insect-eaters so much about diversity in the kitchen. If we think that normalizing insect-eating offers a way to reclaim our past and renew our identity as humans, would these insect-eating communities not be excellent sources for new ideas as to how to do this?

  While our global agri-food technocultures build or patch walls and fuss over efficiencies of process and economies of scale, where else but from among these minorities will come the voices of renewal? If eating insects offers us a “last great hope to save the planet,” in Daniella Martin’s memorable words, where else can we find the sanctuaries, the lost or silenced voices capable of articulating the right questions?

  Thomas Cahill, in How the Irish Saved Civilization, argues that after the rich and powerful Roman Empire collapsed under the combined weight of its own bullying sens
e of self-importance and invasions by Goths, Visigoths, and Vandals, it was from small, vibrant Irish monasteries that philosophy, Greek learning, ancient manuscripts, a sense of humor, and civilized ways of discourse reseeded the darkened European cultural landscape. Similarly, Cahill suggests that, even as our arrogant, globalized, profit-driven civilization collapses into religious and trade wars under the weight of its own inequities and iniquities, societal and human renewal is “germinating today not in a boardroom in London or an office in Washington or a bank in Tokyo, but in some antic outpost or other”77 — that is, from the margins.

  I am willing, at least for the sake of argument, to accept Cahill’s assertion, but I am left with many questions: for what are we seeking the margins? This is not the Roman Empire we are talking about here, with the Euphrates River and Hadrian’s Wall to proclaim its borders. In 1973, social planners Horst and Webber proposed that there are some problems which, because of messy boundaries, complex interactions, and different perspectives on what constitute solutions, cannot be tackled using conventional problem-solving or scientific methods.78 They labeled these wicked problems. Often, what we see as an individual problem is in fact a subset of a much bigger, messier, problematic situation, which technical problem-solvers are trying not to think about.

  In a wicked situation, solving what appears to be a single problem as if it were independent of its context often generates outcomes that are more troublesome than the original dilemma. For instance, we might rid a country of malaria by paving over the swamps where the mosquitoes live, but the loss of water infiltration decreases the groundwater recharge and leads to long-term water shortages, and the radiant heat generated by the pavement adds to local heat islands and contributes significantly to regional warming. Ironically, pools of stagnant water on parking lots and in storm sewers — which are free of insect predators such as fish — are better habitats for many mosquitoes than healthy swamps. Or we might solve a food production deficit through economies of scale, thereby creating ideal conditions for epidemics and putting smallholder farmers out of work.