Agriculture: Pesticides drive species extinction

Pesticides are used worldwide in modern agriculture to combat undesirable organisms—so-called pests—and secure crop yields. But these chemical crop protection products do not act only on the intended target organisms; they also harm a wide range of plants, animals and microorganisms that are essential to ecological balance. A comprehensive study, published in the journal Nature Communications, shows that pesticides contribute significantly to the biodiversity crisis and thereby further accelerate global species loss.

What are pesticides?
Pesticides are chemical or biological substances used for pest control. They serve to protect plants in agriculture, horticulture or forestry from insects, fungi, weeds and other harmful organisms. Depending on the target group, pesticides are divided into different categories: insecticides combat insects, fungicides target fungi, herbicides kill or inhibit the growth of plants, and bactericides combat bacteria.

Study reveals the consequences of pesticide use

The current meta-analysis is based on a systematic evaluation of 1,705 scientific studies containing a total of 20,212 measurements on the effects of 471 different pesticide types. The analysis highlights negative effects on more than 800 species, including vertebrates, invertebrates, plants and microorganisms.

The researchers examined not only laboratory and field experiments from different climate zones, but also the influence of pest control agents in aquatic and terrestrial ecosystems. They analyzed parameters such as growth, reproduction, the behavior of organisms and physiological biomarkers (for example metabolic changes or cell activity). One particular focus was the question of whether new pesticides are more environmentally friendly than older active ingredients. But the study shows that newer products also bring no significant improvements for the environment.

Results: Pest control agents cause harm on a large scale

Negative effects on animals

The results suggest that pesticides impair the growth, reproduction and behavior of numerous animal species. Insects, which play an essential role in pollinating many plants, are particularly affected. But amphibians, birds and fish also show clear impairments.

Pesticides inhibit the growth of many animals, shorten their lifespan and impair their reproduction—which can endanger entire populations in the long term. The behavior of affected animals also changes: escape responses are disrupted, orientation declines, and food intake is restricted. Particularly alarming are the proven neurotoxic damages, which do not affect only individual animals but can also impact entire ecosystems.

Damage to plants and soil ecology

Plants are also affected by the use of chemical pest control products. The study shows reduced biomass, lower germination rates and reduced pollen fertility. In addition, pesticides negatively influence essential metabolic processes such as photosynthesis and water uptake.

The impact on soil microorganisms, which are responsible for nutrient cycling and humus formation, is particularly problematic. By reducing beneficial bacteria and fungi, soil fertility can deteriorate in the long term, which in turn affects crop yields.

Resistance development in pests

Another problem caused by high pesticide use is the development of resistance. When such agents are used in large quantities, many pests adapt so that the products become less and less effective over time. This leads to the need for ever stronger chemical crop protection products—a vicious circle with far-reaching ecological consequences.

Pesticides as a cause of species extinction

The harmful effects of pesticides on non-target organisms have been known for decades. As early as the 1960s, Rachel Carson used her book Silent Spring to draw attention to the devastating consequences of pesticide use.

The peregrine falcon (Falco peregrinus) suffered drastic population declines between the 1950s and 1970s because the insecticide DDT accumulated in the food chain and led to brittle eggshells. The California condor (Gymnogyps californianus) was also affected because, as a scavenger, it ingested pesticide residues. Intensive conservation measures prevented its extinction, but it remains one of the world’s most threatened bird species.

The great bustard (Otis tarda) suffers from the widespread use of pesticides because its food supply is reduced. As a ground-nesting bird, it depends on a diverse landscape, but the loss of wild herbs and insects makes reproduction more difficult. Numerous fish, amphibians and insects are also affected. Particularly alarming is the decline of butterflies, wild bees and other pollinators, whose populations in many regions have fallen by more than 75 percent.

Solutions: Alternatives to pesticide use

The researchers emphasize that there are numerous more environmentally friendly alternatives for reducing the use of pest control agents without endangering agricultural productivity. One promising approach is Integrated Pest Management (IPM), in which different methods are combined to control pests naturally. One central strategy is the promotion of beneficial organisms by planting wildflowers and beetle banks to attract the natural enemies of pests. In addition, crop rotation, meaning the regular change of cultivated crops, can help interrupt pest cycles and make their reproduction more difficult. A targeted adjustment of planting times also helps avoid peak pest periods and thus reduce infestation.

In addition to these agricultural measures, there are further options for mechanical and biological pest control. Physical barriers such as nets or traps prevent pests from reaching the plants, while the targeted use of natural enemies, such as ladybirds or roundworms (nematodes), regulates pest populations in a natural way. Another effective method is the promotion of biodiversity in gardens and on agricultural land to stabilize ecological balance and minimize the occurrence of pests.

Government support programs can also help reduce the use of pest control agents. One example is the British government’s Sustainable Farming Incentive, under which farmers receive financial support if they reduce the use of insecticides in their fields. Similar programs could be introduced worldwide to promote more sustainable agriculture and facilitate the transition to alternative crop protection methods.

Global consequences: Threats to entire ecosystems

The effects of pesticides are not limited to individual species, but threaten entire ecosystems and food webs. In agricultural regions in particular, the decline of insects and pollinators means that plants are pollinated less efficiently, which in the long term endangers food production. In waters, pesticide residues accumulate and harm fish, amphibians and other aquatic organisms—with far-reaching consequences for animals that depend on these food sources.

When individual species fail, the entire ecological balance starts to wobble. The study shows that pesticides not only cause short-term damage, but also undermine the stability of ecosystems in the long term. A more conscious and reduced use of these chemical crop protection products is therefore urgently required to avoid irreversible damage.

The low cost of pest control agents obscures their long-term consequences. To protect biodiversity and curb ecological damage, stricter regulation, better risk assessment and targeted investment in sustainable alternatives are needed. Only then can the negative impacts on the environment and agriculture be limited.

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Source

• Wan, NF., Fu, L., Dainese, M. et al. Pesticides have negative effects on non-target organisms. Nat Commun 16, 1360 (2025). https://doi.org/10.1038/s41467-025-56732-x