Insects play a vital role across ecosystems worldwide, and their unprecedented decline poses a serious threat to ecological balance. They are essential for maintaining biodiversity and safeguarding the delicate systems that sustain life on Earth.
Globally, insect populations are declining at an alarming rate. A 2019 study published in Biological Conservation revealed that over 40% of insect species are in decline, with a third of them at risk of extinction in the coming decades. According to the United Nations, the rate of insect extinction is occurring eight times faster than that of mammals, birds, and reptiles, as reported by Earth, a website specializing in science and climate.
Insect Decline in Europe’s Nature Reserves
Insect populations continue to decline, with studies showing that in Europe, insect numbers in nature reserves have dropped by more than 75%—a trend mirrored in North America. Reports also indicate steep declines in tropical insect populations, such as those found in Costa Rica.
The loss of insect populations can have serious consequences for ecosystems, agriculture, and global food security. Key drivers behind this decline include pesticide use, habitat destruction, climate change, and pollution.
Why Are Insect Populations Declining?
Many insect species depend on leaf litter, decaying wood, and uncontaminated soil—elements often removed or disrupted when land is cleared or altered. This threatens their survival. Climate change, including rising temperatures and shifts in rainfall patterns, has also made it harder for many species to adapt.
Light Pollution and Insect Disappearance
Various forms of pollution further contribute to the decline. Light pollution disrupts nocturnal insects such as beetles and moths by interfering with their movement, reproduction, and ability to avoid predators. Chemical pollution poses an even greater threat; industrial runoff and vehicle emissions contaminate soil, air, and water, harming numerous insect species.
The Importance of Insects
So why are insects so crucial? One of their most vital roles is pollination. Insects like bees, butterflies, beetles, and flies are responsible for pollinating 75% of flowering plants and 35% of global crop production. Without them, the reproduction of many plant species would be disrupted, impacting natural biodiversity, human nutrition, and agricultural economies.
Insects also play a key role in decomposition. Species such as beetles, flies, and ants break down dead organisms, waste, and plant matter, returning nutrients to the soil and maintaining ecosystem health. Without their activity, organic matter would accumulate, slowing the natural recycling of nutrients, weakening plant growth, and destabilizing food webs.
Moreover, insects are a foundational part of many food chains. They serve as a primary food source for birds, amphibians, reptiles, and fish. The disappearance of insects would have direct consequences for these species and the ecosystems they inhabit.
Interestingly, some insects—like beetles, lacewings, and parasitic wasps—also act as natural pest control agents. Their loss would likely increase farmers’ reliance on chemical pesticides and synthetic fertilizers, intensifying environmental and health risks.
Reversing the Decline
Addressing insect decline requires coordinated efforts: protecting habitats, reducing pesticide use, promoting public education, and adopting mitigation and adaptation strategies. This includes sustainable farming practices, policy changes, and raising awareness about the critical role insects play in sustaining life on Earth.
