What We Know

Agriculture as a leading and pervasive driver of insect decline

• › “Annual and perennial non-timber crops” is the top-ranked threat for terrestrial insects in expert elicitation, and agriculture broadly (alongside pollution and climate change) is identified as one of the dominant threats to insects globally. (Bladon et al., in review; Dicks et al., 2021, cited in Bladon et al., in review)
• › “Agricultural expansion is the most widespread form of land use change, with over one third of the terrestrial land surface used for crops or livestock farming.” “Over 40,000 species listed in the IUCN Red List are threatened by agriculture, and arable farming accounts for risks posed to over 80% of these species.” (IPBES. 2019, IUCN. 2021, cited in Mancini et al., 2023)
• › “In high-intensity agriculture — typically characterised by chemical input, low crop diversity, large field size, mechanisation, or high livestock density — insect total abundance and species richness were reduced by 45% and 33% respectively compared with primary vegetation; in low-intensity agriculture, reductions were 19% and 22%”. (Outhwaite et al., 2022)
• › “Invertebrates are particularly susceptible to some farming practices, such as pesticide use and ploughing, and to the landscape-scale consequences of intensive agriculture, such as landscape simplification and the loss of wild plants and natural habitat.” (Köhler HR, Triebskorn R. 2013, Woodcock BA, et al. 2016, Gonthier DJ, et al. 2014, cited in Mancini et al., 2023)
• › “Insect biodiversity continues to decline in cropland areas, suggesting that current policies and practices are not providing adequate protection.” (Mancini et al., 2023)

Mechanisms

How agriculture affects insects

Habitat loss and landscape simplification

• › “The conversion of land from natural habitat to human use causes habitat loss, fragmentation, and degradation.” “Agricultural intensification (including pesticide and fertiliser application, mechanisation, reduced plant diversity, and landscape simplification) is associated with additional declines” beyond habitat loss alone. (Bianchi et al. 2006 and Potts et al. 2010, cited in: Smith et al., in review)
• › As cropland cover increases, refuge habitats and complementary food resources become scarce and more dispersed across the landscape, exacerbating the impacts of intensive management practices on invertebrates. (Mancini et al., 2023)
• › “Many species were lost from traditional farming systems due to the loss of non-crop habitat (such as grassland and field boundaries), which provide crucial resources including food, nesting habitat, and overwintering sites. Other aspects of intensive farming — including the switch from spring to winter sowing, intensive use of agrochemicals, and cultivation methods such as ploughing — have also been associated with a reduction in farmland biodiversity.” (Mancini et al., 2023)

Pesticides and agrochemicals

• › “Insecticide and herbicide use is a strong driver of declines in farmland invertebrates; however, pesticides are not the only driver, with habitat and landscape complexity also being important.” (Köhler and Triebskorn 2013; Woodcock, et al. 2016; Gonthier, et al. 2014, cited in: Mancini et al., 2023)
• › “Pesticide resistance may actively select for certain species in agricultural settings, increasing their abundance, whereas the majority are adversely affected.” (Huang et al., 2014, cited in: Cooke et al., 2025)

Livestock and freshwater impacts

• › “Livestock presence in and around freshwater can cause increases in nutrients and sediment, and can lead to a reduction in riparian vegetation and bank stability. Runoff nutrients, sediment, bacteria, and other pollutants are accumulated in lentic systems (e.g., ponds, wetlands), and dispersed downstream in lotic (rivers, streams) systems.” (Barnes et al., 2025)
• › “Combined threat rankings from the Red List assessments and the GLiTRS expert elicitation workshops have determined livestock farming and ranching to be one of the major threats to Odonata and other aquatic insects.” (Barnes et al., 2025)

Interactive effects with climate change

• › “Synergistic interactions between land use and climate change were associated with large reductions in insect biodiversity within intensively used agricultural systems that experienced substantial climate warming. Warming equivalent to 1 s.d. of baseline temperature variation led to 49% and 27% reductions in insect abundance and species richness in intensive agriculture, respectively, compared with those in primary vegetation with no climate warming.” (Outhwaite et al., 2022)
• › “High-intensity agriculture combined with climate change might affect insects by reducing the availability of microclimate refugia.” (Smith et al., in review)
• › “Within cropland experiencing novel temperatures (standardized temperature anomaly = 1), pollinator abundance is 61.1% lower than in natural habitat that has not experienced temperature increases.” (Millard et al., 2023)
• › Responses are highly variable across Orders: Lepidoptera show the greatest reductions, with richness and abundance differences of −67% and −71% respectively in high-intensity agriculture compared to primary vegetation. “Relying on the average response of insects would strongly underestimate changes in Lepidopteran richness and abundance.” (Smith et al., in review)

Consequences

For ecosystem services, natural capital, and human wellbeing

Biodiversity loss

• › “Overall species trends are more negative in areas of high-cropland cover than in areas with low-cropland cover”, with the strongest evidence for negative effects on bees and spiders. (Mancini et al., 2023)
• › “The loss of historically sensitive species has effectively filtered communities to leave more robust biodiversity assemblages, with a prevalence of generalist rather than specialist species, reducing functional diversity and long-term resilience.” (Vinebrooke et al. 2004; Côté and Darling. 2010, cited in: Mancini et al., 2023)
• › For most taxonomic groups, declines appear to have accelerated over recent years, potentially attributable to changes in insecticide types and severity, habitat changes around cropland, climate change, and interactions between drivers. (Mancini et al., 2023)

Pollination and food security

• › “This loss of insect biodiversity in agricultural systems will probably reduce the provision of ecosystem services essential to agriculture such as pollination and pest control. Moreover, theory suggests that declines in biodiversity could reduce the resilience of natural and agricultural ecosystems to future shocks such as those from extreme climatic events.” (Dainese et al 2019; Grab et al. 2019; Rusch et al. 2016; Oliver et al. 2015, cited in: Outhwaite et al., 2022)
• › “Pollen limitation from animal pollinator losses has already been shown to reduce the reproductive success of wild plants and the productivity of certain crops.” (Biesmeijer et al 2006; Rodger et al 2021; Klein et al 2003, cited in: Millard et al., 2023)
• › “The increased production risk due to loss of pollinators could lead to increased income insecurity for some of the most vulnerable people globally” — particularly smallholder farmers producing cocoa, coffee, and other pollination-dependent crops in the tropics. (Millard et al., 2023)

Pest dynamics

• › “Crop domestication has selected for some insects to become agricultural ‘pests’”, and “pesticide resistance may actively select for certain species in agricultural settings, increasing their abundance, whereas the majority are adversely affected.” (Bernal et al. 2019; Chen 2016; Huang et al 2014, cited in: Cooke et al., 2025)

Mitigation Options

Action	Feasibility	Cost	Scale	Notes
Reduce agrochemical inputs	High	Low–Medium	Local–Regional	Reducing pesticide and fertiliser use is a key lever for both terrestrial and freshwater insect communities; current policy and practice are not providing adequate protection. (Mancini et al., 2023)
Maintain and restore non-crop habitat	High	Low–Medium	Local–Regional	“Natural habitats provide microclimates that offer shelter from more extreme temperatures in agricultural areas” and buffer negative impacts of both agriculture and climate change. “In areas of low-intensity agriculture with 75% natural habitat cover, insect abundance and richness were reduced by only 7% and 5% compared with primary vegetation with no climate warming, versus reductions of 63% and 61% with only 25% cover.” (Outhwaite et al., 2022)
Diversify agricultural landscapes	High	Low–Medium	Landscape	“A synthesis of studies found that heterogeneous agricultural landscapes, on average, support a more diverse insect community.” (Estrada–Carmona et al. 2022, cited in: Dicks et al., 2024) Landscape complexity is an important driver of insect richness and abundance alongside pesticide use. (Mancini et al., 2023)
Catchment-scale livestock management	Medium	Medium	Landscape	“Herbst et al. (2012) reported a significantly larger increase in EPT abundance and richness when cattle were removed at a catchment scale, compared to removal from a local, stream reach scale.” (Barnes et al., 2025)
Diversify grazing and cutting regimes	High	Low	Local	“At the field scale, changes in management such as diversifying grazing or cutting regimes may increase the variation in vegetation structure to create pockets of cooler and warmer habitat.” (Bladon et al., 2024)
Mitigate climate change	Medium	Very High	Global	“The predicted rate of increase in average pollination production risk is substantially higher under RCP 6.0 than RCP 2.6, suggesting that efforts to mitigate climate change will reduce risk to future crop production.” (Millard et al., 2023)

Evidence Gaps

• › The data used in major analyses were collected in the recent past (1992–2012) and mostly from regions with a long history of human pressures. It is probable that all sites have undergone some degree of human disturbance and the “baseline” primary vegetation may have already experienced biodiversity change or loss, meaning the effect of historical land-use change on insect diversity has likely been underestimated. (Ellis & Ramankutty 2008; Newbold et al. 2025, cited in: Smith et al., in review)
• › “Both land use and biodiversity data on the immediate post-Second World War period associated with the most intensive phase of agricultural change are often lacking”, suggesting the full extent of historic losses is unknown. (Mancini et al., 2023)
• › The Northern Hemisphere is overrepresented in existing datasets; geographic bias limits understanding of agricultural impacts in the Global South, where agricultural intensification is accelerating and the majority of pollination-dependent crops are grown. (Smith et al., in review; Millard et al., 2023)
• › “Broadly, the differing patterns observed for abundance and richness suggest that the presence of livestock may influence aquatic insect biodiversity at finer taxonomic resolutions than broad assessments at Order-level scale can discern. The stable abundance observed alongside reduced richness suggests shifts in community composition that will only be detectable via examinations of functional groups or lower taxonomic levels.” (Barnes et al., 2025)
• › “There is considerable variation within Orders particularly those with heterogenous species ecologies and life histories.” The wide confidence intervals for Hymenoptera, for example, likely reflect different responses among bees, wasps, and ants. (Smith et al., in review)
• › “It is impossible to predict exactly how estimates of pollination production risk will translate into actual crop production losses”, given multiple uncertainties including crop distribution changes, managed pollinator buffering, and the economic viability of alternative pollination strategies. (Millard et al., 2023)
• › “Understanding the impact of individual threats is an important first step, but excluding studies which grouped livestock into the broader land-use class of ‘agriculture’ excluded data from mixed crop-livestock farming systems, which were more common in Africa and Asia. This perpetuates existing geographical knowledge gaps in conservation and biodiversity research. Further research on the impacts of other types of human disturbances, specifically those in mixed systems, is crucial to increase coverage of global studies and examine biodiversity trends in a rapidly changing world.” (Barnes et al., 2025)

GLiTRS References

• Barnes, L. A., Wenban-Smith, E., Skinner, G., Dicks, L. V., Millard, J., & Bladon, A. J. (2025). Differing Impacts of Livestock Farming and Ranching on Aquatic Insect Biodiversity: A Global Meta-Analysis. Global Change Biology, 31(9), e70513. https://doi.org/10.1111/gcb.70513
• Bladon, A. J., Cooke, R., Millard, J., & Outhwaite, C. L. (2024). Practical solutions to climate change for insect conservation. In Routledge Handbook of Insect Conservation. Routledge.
• Bladon, A. J., Outhwaite, C. L., Cooke, R., Millard, J., Rodger, J. G., Isip, J., Dyer, E. E., Skinner, G., Hui, C., Jones, I., Murphy, J. F., Kietzka, G. J., Woodcock, B. A., Newbold, T., Roy, H., Isaac, N. J., Purvis, A., & Dicks, L. V. (in review). What’s driving insect decline? Current Opinion in Insect Science.
• Cooke, R., Outhwaite, C. L., Bladon, A. J., Millard, J., Rodger, J. G., Dong, Z., Dyer, E. E., Edney, S., Murphy, J. F., Dicks, L. V., Hui, C., Jones, J. I., Newbold, T., Purvis, A., Roy, H. E., Woodcock, B. A., & Isaac, N. J. B. (2025). Integrating multiple evidence streams to understand insect biodiversity change. Science, 388(6742), eadq2110. https://doi.org/10.1126/science.adq2110
• Dicks, L. V., Grames, E. M., Bowler, D. E., & Isaac, N. J. B. (2024). Insect declines – an overview of current knowledge on the status of the world’s insects. In Routledge Handbook of Insect Conservation. Routledge.
• Mancini, F., Cooke, R., Woodcock, B. A., Greenop, A., Johnson, A. C., & Isaac, N. J. B. (2023). Invertebrate biodiversity continues to decline in cropland. Proceedings of the Royal Society B: Biological Sciences, 290(2000), 20230897. https://doi.org/10.1098/rspb.2023.0897
• Millard, J., Outhwaite, C. L., Ceaşu, S., Carvalheiro, L. G., da Silva e Silva, F. D., Dicks, L. V., Ollerton, J., & Newbold, T. (2023). Key tropical crops at risk from pollinator loss due to climate change and land use. Science Advances, 9(41), eadh0756. https://doi.org/10.1126/sciadv.adh0756
• Outhwaite, C. L., McCann, P., & Newbold, T. (2022). Agriculture and climate change are reshaping insect biodiversity worldwide. Nature, 605(7908), 97–102. https://doi.org/10.1038/s41586-022-04644-x
• Smith, K. N., Newbold, T., Millard, J., Cooke, R., Bladon, A. J., Purvis, A., Isaac, N. J. B., Jones, J. I., Roy, H., Cang, H., & Outhwaite, C. (in review). Interactions of land use and climate change disproportionately impact Lepidoptera of the five major insect orders. Insect Conservation and Diversity.

Secondary citations (cited within GLiTRS papers)

• Dicks et al., 2021; IPBES, 2019; IUCN, 2021; Bianchi et al., 2006; Potts et al., 2010; Köhler & Triebskorn, 2013; Woodcock et al., 2016; Gonthier et al., 2014; Huang et al., 2014; Dainese et al., 2019; Grab et al., 2019; Rusch et al., 2016; Oliver et al., 2015; Biesmeijer et al., 2006; Rodger et al., 2021; Klein et al., 2003; Bernal et al., 2019; Chen, 2016; Vinebrooke et al., 2004; Côté & Darling, 2010; Estrada-Carmona et al., 2022; Ellis & Ramankutty, 2008; Newbold et al., 2025; Hughes et al., 2021; Herbst et al., 2012