The Causes and Implications of Mass Insect Extinctions

The biodiversity of insects is threatened worldwide- We need to take action now

Photo by Boris Smokrovic on Unsplash

Summary Points

  • The biodiversity of insects is threatened worldwide. Dramatic rates of insect decline may lead to the extinction of 40% of the world’s insect species over the next few decades.
  • The current rate of insect decline is eight times faster than that of mammals, birds and reptiles. Any insect population collapse would have detrimental repercussions for nature’s ecosystem.
  • The current industrial agriculture model is the primary driver of biodiversity loss. Corporate concentration in the global food system has lead to an increased use of agrochemicals, fertilizers and pesticides. As well as the conversion of natural habitats to land used for mono cropping.
  • There is a need for landowners to adopt a landscape approach, which combines conservation, sustainable management and restoration. These three elements are integral parts of a single coherent land management framework.

The Current State of Affairs

The worldwide reduction in biodiversity undergone by many terrestrial and aquatic vertebrates has been a major and longstanding concern of biologists and ecologists.[1] More recently, significant population declines of invertebrate taxa, particularly insects, have sparked trepidation amongst many scientists.[2] Population declines denote a more restricted geographical distribution of species, and represent the first step towards extinction.[3]

Human activities are the primary cause of biodiversity loss.[4] Hunting, deforestation, agricultural expansion and intensification, industrialization and urbanization jointly claimed a 30–50% encroachment on natural ecosystems at the end of the 20th century.[5] Industrial agriculture, characterized by large-scale monoculture, heavy use of chemical fertilizers and pesticides is one of the main drivers of population declines in insects.[6]

The conversion of natural habitats for large-scale agriculture has lead to a scarcity of small family farms, known for open pastures, hedgerows, and other areas where “weedy” plants like wildflowers can grow. These areas are perfect for insects; the removal of these areas has certainly played a role in the reduction of insect biomass, as has the draining of wetlands and swamps.[7]

Declining Insect Species

Insects are the most diverse group of organisms, comprising two thirds of all terrestrial species on Earth. Over 1 million insect species are named, however 80% remain to be discovered.[8] New research shows that large-scale declines in insects are a phenomenon that requires serious attention. A study published recently in the journal Biological Conservation concluded that dramatic rates of population decline might lead to the extinction of 40% of the world’s insect species over the next few decades.

The biologists conducted a systematic review of 73 historic reports of insect declines across the world and emphasized that: not only are the number of species declining, the biomass of insects as a whole is also declining at a high rate of 2.5% per year.[9] At a constant rate of decline at 2.5% this converts into a reduction of 25% of insect biomass within the next decade, and a 100% decline in insect biomass within the next 100 years.

In other words, within the next century all insects could disappear.[10] The current rate of insect decline is eight times faster than that of mammals, birds and reptiles. Any insect population collapse would have repercussions for nature’s ecosystem.

The Importance of Insects

The anthropogenic erosion of biodiversity has a direct impact on the ecosystem services essential for civilization.[11] In terrestrial ecosystems, Lepidoptera (Butterflies and Moths), Hymenoptera (sawflies, wasps, ants, bees) and Coleoptera (beetles) are the taxa most affected.

Four major aquatic taxa (Odonata, Plecoptera, Trichoptera and Ephemeroptera) have already lost a considerable proportion of species. Affected insect groups not only include specialists that occupy particular ecological niches, but also many common and generalist species.[12] Insects serve as the base of the food web. They are eaten by a variety of vertebrates such as shrews, moles, hedgehogs, anteaters, lizards, amphibians, most bats, many birds and fish feed on insects or depend on them for rearing their offspring.

If insects decline, everything else will as well.[13] In particular, butterflies and moths are valuable indicators of environmental quality for their high degree of host-plant specialization and vulnerability to habitat deterioration.[14] Given their presence in a broad range of habitats, the loss of Lepidoptera may directly impact the delivery of key ecosystem services such as pollination and natural pest control.[15]Moths, which are about 10 times more diverse than butterflies, constitute important prey items of bats and help sustain population levels of countless other animals.[16]

The Role of Pollinators

Collectively, the Hymenoptera are most important to humans as pollinators of wild and cultivated flowering plants, and as makers of honey.[17] For example, bees and wasps are the most significant agents for the pollination of flowers; they are found virtually everywhere that flowering plants occur.

Pollinators are essential to the production micronutrient rich fruits, vegetables, nuts, seeds and oils. Around 75 percent of the world’s crops producing fruits and seeds for human consumption depend on pollinators for sustained production, yield, and quality.[18] Pollinators are the primary reason we are able to enjoy a diversity of food. Additionally, pollinators not only contribute to increased food security, they hold extreme economic significance.

Pollination-dependent crops are five times more valuable than those that do not need pollination. The price tag of global crops directly relying on pollinators is estimated to be between US$235 and US$577 billion a year.[19] Several of the crops produced with pollination, such as cocoa and coffee, provide income for farmers, in particular smallholder farmers and family farms, especially in developing countries.

The Impact of the Industrial Agriculture Model

Agriculture is the largest contributor to biodiversity loss for two main reasons:

(1) The conversion of natural habitats to intensely managed systems.[20] Agriculture is the single largest land use, covering over a third of the world’s land surface excluding Greenland and Antarctica.[21]

(2) Agricultural intensification is linked to the use of agrochemicals. Intensive agriculture implies the systematic and widespread use of pesticides for controlling crop pests (insecticides), competing weeds (herbicides) and fungal infections (fungicides) among others.[22]

In terms of toxicity, insecticides are by far the most toxic to all insects and other arthropods, followed by fungicides.[23] Herbicides reduce the biodiversity of vegetation within the crops, thus indirectly impacting arthropod species that depend upon wild plants, which either disappear completely or decline significantly in numbers.[24] Furthermore, since the 1980s neonicotinoid pesticides have become the most widely used class of insecticides worldwide. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market.[25] Recent meta-studies found that systemic insecticides seriously damage invertebrates, amphibians and birds.[26]

In particular, residues of neonicotinoid insecticides in pollen pose high risk to honeybees and bumblebees.[27] Apart from pesticides, the introduction of synthetic fertilizers early in the 20th century is recognized as a key driver of pollinator losses in the U.K. and Europe, particularly among specialist bumblebees.[28] Total fertilizer demand was estimated to be 184.02 million tonnes in 2015. With an average annual growth of 1.9 percent in the following years, it is expected to reach 201.66 million tonnes by the end of 2020.[29]

The Influence of Corporations over the Agricultural Model

In order to find solutions to the current situation a few key questions need to be addressed:

  • If we know the agro-industrial model is the leading cause of invertebrate population declines — how did it get so bad?
  • Why are so many farmers’ globally using chemically altered seeds, fertilizers, and pesticides?

It is imperative to examine the role of corporate concentration in the global food system. There has been a strong tendency in more industrialized countries, including the United States, to move away from competition and towards higher levels of concentration. As markets go through this process of consolidation, the average firm size increases, barriers to entry for other firms rise, and the remaining firms have more influence over prices as well as a greater potential for higher profits.[30] Because we need food to live, concentration raises more concern in food industries than in most other economic sectors.

The ways in which power is exercised over the food system, has huge repercussions for the environment. Corporate concentration is a trend occurring throughout the entire industrial food system. Concentration in the food system largely takes on the form of Oligopolies; markets that are dominated by several large firms but are characterized by very limited forms of competition sometimes described as “shared monopolies”.[31] Concentration impacts the full breadth of products purchased by producers to grow food, feed, and fuel: seeds and agrochemicals, fertilizers, animal pharmaceuticals, livestock genetics and farm equipment.[32]

Today, the proprietary seed industry is intimately linked to the world’s largest agrochemical corporations. Syngenta (Switzerland), Bayer (Germany), BASF (Germany), DuPont (USA), Monsanto (USA), and Dow (USA), known as the ‘Big Six’, currently control both 60 % of the global seed market and 75% of the global pesticides market. The fertilizer industry boasted annual revenue of $183 billion in 2014.[34] The top ten companies account for a 56% market share, through a wide variety of global networks and brands.[35]

A range of factors make the sector inherently concentrated, unlike other agri-food sector industries, the fertilizer industry is driven by intensive requirements for location-specific raw materials, such as minerals and natural gas. As a result, the sector has been historically structured around government-sanctioned export cartels based on the types of fertilizers located within their borders. Canada, China, the United States, India, and Russia control over 50% of the world’s production of the primary materials needed to produce fertilizers (e.g. ammonia, phosphate, potash). Within each country, the top four firms control over half of production.[36]

Biologist Sánchez-Bayo, and Wyckhuys of the recent study published in Biological Conservation state that: “Habitat restoration, coupled with a drastic reduction in agro-chemical inputs and agricultural ‘redesign’, is probably the most effective way to stop further [insect] declines, particularly in areas under intensive agriculture.”[37] However, these policy objectives cannot be achieved without recognizing the power and influence many agri-businesses hold over the global food system. Many farmers have been, and continue to be trapped into this industrial model.[38]

Around the 1950s agricultural chemical companies in the United States systematically reduced the self-reliance of farmers and increased the use of synthetic pesticides and herbicides. In order to increase profits, prominent chemical firms such as Monsanto made multiple acquisitions of smaller seed companies. Monsanto, in particular, has successfully linked proprietary seeds and herbicides. Notable court cases such as Asgrow v. Winterboersignalled a shift in enforcement of plant intellectual property rights from litigation against corporate competitors to lawsuits against the end use-farmer.”[39] With these changes Monsanto could enlist government support to enforce its contractual restrictions on farmers who bought Roundup Ready seeds, which is a requirement if a farmer wishes to purchase Monsanto’s patented herbicide. The company is able to legally enforce a prohibition on seed saving under strict intellectual property rights laws.[40]

What can International Organizations do to Solve this Problem?

The United Nations Environment Programme, as well as the Food and Agricultural Organization, have codes of conduct and management strategies regarding the use of chemical and hazardous waste. These guidelines are used as a guiding tool for many countries around the globe.[41] Therefore, it is important that leading global institutions are aware of a variety of land management practices in order to reduce the overall amount of chemicals being put into the Earth.

Increase Conservation Efforts: One effective way of protecting ecosystems is through protected areas: land and water that act as sanctuaries for species and ecological processes that cannot survive in intensely managed landscapes and seascapes. Protected areas often help preserve ecosystem services, cultural landscapes, fragile human communities, sacred natural sites and recreational areas.

Secure the Land Tenure Rights of Small Scale farmers: Small-scale farmers have been the essence of rural livelihoods and backbone of food production for millennia. They are under immense stress from land degradation, insecure tenure, and a globalized food system that favors concentrated, large-scale, and highly mechanized farms. Large-scale land acquisitions have increased dramatically in the last two decades. The international community needs to be mindful of not selling land for industrial uses.[42]

Promote the Use of Sustainable Land Management Practices: Higher crop yields can be achieved through reductions in pesticide use and an increase in intra-specific crop diversity to manage pests. Efficient agriculture does not need to rely on large-scale monocultures. Small-scale, labour-intensive, low-input farming systems frequently lead to higher yields.[43]

Encourage the use of Integrated Landscape Approaches that Include Restoration: The main aim of restoration is to reinstate resilient and adaptable ecosystems. Many ecosystems are already at a stage where the long-term survival of endemic species is threatened. Restoration efforts will need to be designed to the specific landscapes and ecosystem for which they are being applied to.

FOOTNOTES

[1]Régnier, et al., “Mass Extinction in Poorly Known Taxa.” Proceedings of the National Academy of Sciences 112, no. 25 (2015): 7761–766.

[2] Ibid; (See: Timothy Schowalter, 2019)

[3] Diamond, J. “The Present, Past and Future of Human-Caused Extinctions.” Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences 325, no. 1228 (1989): 469–77.

[4] Ceballos, Gerardo, Paul R. Ehrlich, and Rodolfo Dirzo. “Biological Annihilation via the Ongoing Sixth Mass Extinction Signaled by Vertebrate Population Losses and Declines.” Proceedings of the National Academy of Sciences 114, no. 30 (2017): E6089–6096; See Maxwell et al.,( 2016),

[5] Vitousek et al., “Human Domination of Earth’s Ecosystems.” Science 277, no. 5325 (1997): 494–99.

[6] Sánchez-Bayo, and Wyckhuys. “Worldwide Decline of the Entomofauna: A Review of Its Drivers.” Biological Conservation 232 (2019): 8–27

[7] Douglas Main “Why insect populations are plummeting- and why it matters” (2019) National Geographic.

[8] Nigel E. Stork. “How many species of insects and other terrestrial arthropods are there on Earth?.” Annual Review of Entomology 63 (2018): 31–45.

[9] Sánchez-Bayo, and Wyckhuys. “Worldwide Decline of the Entomofauna: A Review of Its Drivers.” Biological Conservation 232 (2019): 8–27

[10] Ibid.

[11] Ceballos et al., “Biological Annihilation via the Ongoing Sixth Mass Extinction Signaled by Vertebrate Population Losses and Declines.” Proceedings of the National Academy of Sciences 114, no. 30 (2017): 6089–6096

[12] Sanchez-Bayo and Wyckhuys, (2019)

[13] Douglas Main “Why insect populations are plummeting- and why it matters” (2019) National Geographic.

[14] Fox, Richard. “The Decline of Moths in Great Britain: A Review of Possible Causes.” Insect Conservation and Diversity 6, no. 1 (2013): 5–19.

[15] Ibid.

[16] Hahn et al., Hahn, Schotthöfer, Schmitz, Franke, and Brühl. “The Effects of Agrochemicals on Lepidoptera, with a Focus on Moths, and Their Pollination Service in Field Margin Habitats.” Agriculture, Ecosystems and Environment 207 (2015): 153–62.

[17]Lindauer, Martin. “Hymenopteran”. Encyclopedia Britannica.(2019)

[18] FAO. “The importance of Bees and Other Pollinators for Food and Agriculture.” (2018)

[19] Ibid.

[20] Dudley, Nigel, and Sasha Alexander. “Agriculture and Biodiversity: A Review.” Biodiversity 18, no. 2–3 (2017): 45–49.

[21] Ibid.

[22] Ibid.

[23] Sanchez-Bayo, et al., “Pesticide Residues and Bees — A Risk Assessment.” PLoS ONE 9, no. 4 (2014)

[24] Goulet, Henri, and Lubomir Masner. “Impact of Herbicides on the Insect and Spider Diversity in Eastern Canada.” Biodiversity 18, no. 2–3 (2017): 50–57.

[25] Simon-Delso, et al., “Systemic Insecticides (neonicotinoids and Fipronil): Trends, Uses, Mode of Action and Metabolites.” Environmental Science and Pollution Research 22, no. 1 (2015): 5–34.

[26] Chagnon, Madeleine, David Kreutzweiser, Edward Mitchell, A.D. Morrissey, Christy Noome, and A. Sluijs. “Risks of Large-scale Use of Systemic Insecticides to Ecosystem Functioning and Services.” Environmental Science and Pollution Research 22, no. 1 (2015): 119–34.

[27] Sanchez-Bayo, et al., “Pesticide Residues and Bees — A Risk Assessment.” PLoS ONE 9, no. 4 (2014)

[28] Ollerton et al., “Pollinator Declines. Extinctions of Aculeate Pollinators in Britain and the Role of Large-scale Agricultural Changes.” Science (New York, N.Y.) 346, no. 6215 (2014): 1360–2.

[29] FAO. “World Fertilizer Trends and Outlooks to 2020”. Rome. (2017)

[30] Phillip, Howard. “Who controls what we eat? Corporate concentration in the food system.” (2016)

[31] Ibid.

[32] Mooney, P. “Too big to feed: exploring the impacts of mega-mergers, consolidation and concentration of power in the agri-food sector.” International Panel of Experts on Sustainable Food Systems. (2017).

[33] Ibid.

[34] ETC Group. “Breaking Bad: Big Ag Mega-Mergers in Play Dow + Dupont in the Pocket? Next: Demonsanto?” ETC Communiqué, 115. (2015)

[35] Ibid.

[36] Ibid.

[37] Sánchez-Bayo, and Wyckhuys. “Worldwide Decline of the Entomofauna: A Review of Its Drivers.” Biological Conservation 232 (2019): 26

[38] Phillip, Howard. “Who controls what we eat? Corporate concentration in the food system.” (2016)

[39] Rita, Heimes. “Post-Sale restrictions on Pateneted seeds: Which Law Governs” Wake Forest Intellectual Porperty Law Journal 10 (2) (2010): 109

[40] Phillip, Howard. “Who controls what we eat? Corporate concentration in the food system.” (2016)

[41] UNEP. “Pesticides”. (2019)

[42] Dudley, Nigel and Sasha Alexander

[43]United Nations Convention to Combat Desertification (UNCCD). Global Land Outlook. (2017)

[44] Dudley, Nigel, and Sasha Alexander. “Agriculture and Biodiversity: A Review.” Biodiversity 18, no. 2–3 (2017): 45–49; (See: Bommarco, Kleijn, and Potts 2013)

Ottawa Based Writer- I write articles about underrated and overlooked issues regarding climate change, the environment, and biodiversity loss

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store