Unveiling the Silent Crisis: The Decline of Earth’s Vital Insects
By: Meghan Ward
In the intricate tapestry of Earth’s ecosystems, insects weave a role more vital than most realize. From pollution to nutrient cycling, insects are the unsung heroes that uphold the delicate balance of our planet’s biodiversity. However, in the past few decades a disquieting phenomenon has been unfolding – the silent decline of insect populations. Recent research has shown that insect populations have declined by more than 45% since the 1980s, and another 40% of all insect species will be at risk of extinction within the coming decades.
This alarming trend poses a significant threat not only to insect species but to the entire web of life on Earth. In this blog post, we will delve into the reasons behind the decline of insects and explore why it is critical for humanity to take action to protect these tiny but indispensable creatures.
Tiny Heroes: The Role of Insects
Before we examine the reasons behind the decline of insect populations, it is important to understand the roles insects play in maintaining healthy ecosystems. One of their most critical functions is pollination; a process vital for the reproduction of many flowering plants, including fruits and vegetables. Bees, butterflies, and other pollinators facilitate the transfer of pollen which enables the production of fruits, seeds, and new plants. Approximately 75% of global food crops depend on insect-facilitated pollination, making insects integral to our food supply.
Insects are also decomposers, breaking down dead plant and animal remains and recycling the nutrients back into the soil. Insects like beetle larvae, flies, and ants break down dead material into small pieces, which microbes then fully decompose. Furthermore, insects serve as a primary source of food for many other species higher up the food chain including birds, amphibians, reptiles, and mammals.
Insects also help with crowd control: wasps and other important predatory insects like dragonflies help prevent populations of caterpillars, spiders, and crickets from reaching pest levels. On a global scale, insects provide over $415 billion in pest control each year!
Insects form the foundation of many complex food webs and ecosystems which sustain the intricate balance of our world.
Under Threat: The Reasons Behind Insect Population Declines
The decline of insect populations has been coined a “Death by a Thousand Cuts.” There are a multitude of threats that insects face, and any combination of these threats may cause specific species to decline, or to go extinct. In the following section, we will review a few of the key causes of insect decline, both in Ontario and on a global scale.
Habitat Loss
One of the primary drivers of the decline of insect populations is habitat loss. Insects are found in many different habitat types, including forests, meadows, fields, rivers, streams, and wetlands. However, human activities such as deforestation, urban sprawl, and agricultural expansion have led to the destruction of many natural habitats. Insects rely on specific environments for shelter, reproduction, and foraging. When these habitats disappear, so do the insects.
Pesticides
The wide use of pesticides in modern agriculture has had devastating consequences for insect populations. While these chemicals are designed to target specific pests, they often have unintended effects on non-target insects, like butterflies and bumble bees. In fact, the Rusty patched bumble bee was once common throughout northeastern North America but has since declined by 90% due to pesticide use. Pesticides can contaminate water sources, kill beneficial insects, and disrupt the balance of ecosystems. The decline of pollinators like bees has been attributed, in part, to neonicotinoid pesticides and has raised concern about the future of agricultural productivity and food security.
Xerces Society for Invertebrate Conservation
Climate Change
Rising global temperatures and changes in precipitation patterns associated with climate change pose significant threats to insect populations. Many species have specific temperature and humidity requirements for their life cycles, and changes to these conditions can affect their overall survival. As climate change alters the growth of plants, so too will insects who rely on those plants be affected.
Light Pollution
Artificial light at night, a consequence of urbanization, transportation and industrial activities has been identified as another contributing factor to the decline of insects. Nocturnal insects, like moths and beetles, are drawn to artificial light, leading them away from their natural habitats and exposing them to predators. This disruption in their behaviour affects their ability to mate, to forage, and to live healthy lives.
Beyond Buzzing Wings: The Importance of Insect Conservation
Ecological Balance
The health and stability of ecosystems is dependant on the diversity and abundance of animals within it, including insect populations. A reduction in the amount of insect prey can and will disrupt food webs, leading to cascading effects throughout the entire ecosystem. Additionally, insect declines impact the availability of ecosystem services: the loss of pollinators, for instance, threatens the reproduction of plants that provide food for other species; the loss of insects that decompose dead material will affect soil health, which in turn affects plant growth and all the animals that rely on plants for food. Insects help filter toxins and pollution out of water sources; without insects such as caddisflies in rivers and streams, water quality will decline. Protecting insects is a crucial step in maintaining the resilience and functionality of natural systems.
Food Security
Given their role in pollination, insects are instrumental in the production of many of the world’s crops. In fact, insect pollination is estimated to be worth more than 50 billion dollars per year in the USA alone. The decline of pollinators will have severe consequences for global food security, affecting the availability of fruits, vegetables, and nuts. Without a healthy population of insects, the yield of crops would plummet, leading to increased food costs and food shortages.
Agricultural Sustainability
Insects contribute to agricultural sustainability by providing natural pest control services. Many insects, such as lady bugs and wasps, prey on crop-damaging pests thus reducing the need for pesticides. Protecting insect populations contributes to more sustainable and environmentally friendly agricultural practices.
Preserving Biodiversity: Strategies for Ensuring a Future with Insects
Conservation of Natural Habitats
Preserving and restoring natural habitats is essential for the survival of insect species. This involves protecting areas of high biodiversity, creating wildlife corridors to connect habitats, and implementing measures to reduce habitat destruction. While creating more habitat is important, it is critical that we protect what remains.
Reducing Light Pollution
Addressing light pollution is a relatively simple yet effective way to support nocturnal insect populations like moths and beetles. This includes using more efficient outdoor lighting, directing light downwards, turning off unnecessary outdoor lighting in the evening, and promoting public awareness about the importance of reducing light pollution.
Public Action + Awareness
Raising awareness about the importance of insects and the threats they face is crucial for garnering public support and encouraging informed decision-making. As a community member, you can join community science initiatives, such as the Monarch Watch in Ontario, which helps protect insect populations. Community science initiatives can increase awareness and understanding of local environmental issues, and inspire a connection between individuals, the larger scientific community, and the natural world.
There are behaviours that individuals can adopt to mitigate the drivers of insect declines. For example, insect-friendly habitat can be established by planting native plants, such as Canada Goldenrod, Purple-Stemmed Aster, and Black-eyed Susans – websites offer accessible and specific information about native Ontario plants for pollinators. As a voting member of the public, we encourage you to vote for nature-friendly legislators and legislation.
Guardians of the Small: Our Shared Responsibility to Protect Insects
Insects, despite their small size, play a monumental role in sustaining life on Earth. The decline of insect populations poses a severe threat to ecosystems, biodiversity, and human well-being. By understanding the causes behind this decline and taking decisive action to protect insects, we can contribute to the preservation of some of our planet’s smallest inhabitants. As stewards of the Earth, it is our responsibility to recognize the intrinsic value of insects and work towards creating a world where these unsung heroes can thrive for generations to come.
Images courtesy of Caitlin Rafters
Reference
Chowdhury et al 2017. Ecosystem Services of Insects. Journal of Scientific and Technical Research.
Forister et al 2019. Declines in insect abundance and diversity: we know enough to act now. Society for Conservation Biology.
Gardener’s Supply Company https://www.gardeners.com/how-to/pollinator-garden-design-for-bees/9144.html
https://conbio.onlinelibrary.wiley.com/doi/full/10.1111/csp2.80
Penn State: Huck Institutes of the Life Sciences. Why we need insects. https://www.huck.psu.edu/institutes-and-centers/insect-biodiversity-center/why-we-need-insects
Wagner et al 2021. Insect decline in the Anthropocene: death by a thousand cuts. PNAS. https://www.pnas.org/doi/10.1073/pnas.2023989118
World Wildlife Foundation. 2023. Here’s how insects help keep ecosystems in balance. https://www.worldwildlife.org/magazine/issues/spring-2023/articles/here-s-how-insects-help-keep-ecosystems-in-balance
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