Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

No net insect abundance and diversity declines across US Long Term Ecological Research sites

Matters Arising to this article was published on 05 April 2021

Matters Arising to this article was published on 05 April 2021

Abstract

Recent reports of dramatic declines in insect abundance suggest grave consequences for global ecosystems and human society. Most evidence comes from Europe, however, leaving uncertainty about insect population trends worldwide. We used >5,300 time series for insects and other arthropods, collected over 4–36 years at monitoring sites representing 68 different natural and managed areas, to search for evidence of declines across the United States. Some taxa and sites showed decreases in abundance and diversity while others increased or were unchanged, yielding net abundance and biodiversity trends generally indistinguishable from zero. This lack of overall increase or decline was consistent across arthropod feeding groups and was similar for heavily disturbed versus relatively natural sites. The apparent robustness of US arthropod populations is reassuring. Yet, this result does not diminish the need for continued monitoring and could mask subtler changes in species composition that nonetheless endanger insect-provided ecosystem services.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Map of LTER sites.
Fig. 2: Time trends in arthropod abundance among LTERs.
Fig. 3: Time trends in arthropod diversity among LTERs.
Fig. 4: Change in relative abundance of taxa over time.
Fig. 5: Comparison of species rank abundance and community composition.

Similar content being viewed by others

Data availability

The data supporting the findings of this study (curated arthropod abundances and estimated time trends) are available at the Dryad Data Repository (https://doi.org/10.5061/dryad.cc2fqz645).

Code availability

The R code used to curate and analyse data are available at the Dryad Data Repository (https://doi.org/10.5061/dryad.cc2fqz645).

References

  1. Price, P. W., Denno, R. F., Eubanks, M. D., Finke, D. L. & Kaplan, I. Insect Ecology: Behavior, Populations and Communities (Cambridge Univ. Press, 2011).

  2. Watanabe, M. E. Pollination worries rise as honey bees decline. Science 265, 1170–1170 (1994).

    Article  CAS  PubMed  Google Scholar 

  3. Soroye, P., Newbold, T. & Kerr, J. Climate change contributes to widespread declines among bumble bees across continents. Science 367, 685–688 (2020).

    Article  CAS  PubMed  Google Scholar 

  4. Mathiasson, M. E. & Rehan, S. M. Status changes in the wild bees of north-eastern North America over 125 years revealed through museum specimens. Insect Conserv. Divers. 12, 278–288 (2019).

    Google Scholar 

  5. Powney, G. D. Widespread losses of pollinating insects in Britain. Nat. Commun. 10, 1018 (2019).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  6. Fox, R. The decline of moths in Great Britain: a review of possible causes. Insect Conserv. Divers. 6, 5–19 (2013).

    Article  Google Scholar 

  7. Casey, L. M., Rebelo, H., Rotheray, E. & Goulson, D. Evidence for habitat and climatic specializations driving the long-term distribution trends of UK and Irish bumblebees. Divers. Distrib. 21, 864–875 (2015).

    Article  Google Scholar 

  8. Hallmann, C. A. et al. More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLoS ONE 12, e0185809 (2017).

    Article  PubMed  PubMed Central  CAS  Google Scholar 

  9. Leather, S. R. “Ecological armageddon”–more evidence for the drastic decline in insect numbers. Ann. Appl. Biol. 172, 1–3 (2018).

    Article  Google Scholar 

  10. Habel, J. C., Samways, M. J. & Schmitt, T. Mitigating the precipitous decline of terrestrial European insects: Requirements for a new strategy. Biodivers. Conserv. 28, 1343–1360 (2019).

    Article  Google Scholar 

  11. Sánchez-Bayo, F. & Wyckhuys, K. A. G. Worldwide decline of the entomofauna: a review of its drivers. Biol. Conserv. 232, 8–27 (2019).

    Article  Google Scholar 

  12. Seibold, S. et al. Arthropod decline in grasslands and forests is associated with drivers at landscape level. Nature 574, 671–674 (2019).

    Article  CAS  PubMed  Google Scholar 

  13. Salcido, D. M., Forister, M. L., Garcia Lopez, H. & Dyer, L. A. Loss of dominant caterpillar genera in a protected tropical forest. Sci. Rep. 10, 422 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  14. Wagner, D. L. Insect declines in the Anthropocene. Annu. Rev. Entomol. 65, 457–480 (2020).

    Article  CAS  PubMed  Google Scholar 

  15. Wesner, J. S. et al. Loss of potential aquatic–terrestrial subsidies along the Missouri River floodplain. Ecosystems 23, 111–123 (2020).

    Article  Google Scholar 

  16. Wepprich, T., Adrion, J. R., Ries, L., Wiedmann, J. & Haddad, N. M. Butterfly abundance declines over 20 years of systematic monitoring in Ohio, USA. PLoS ONE 14, e0216270 (2019).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Welti, E. A. R., Roeder, K. A., de Beurs, K. M., Joern, A. & Kaspari, M. Nutrient dilution and climate cycles underlie declines in a dominant insect herbivore. Proc. Natl Acad. Sci. USA 117, 7271–7275 (2020).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  18. Montgomery, G. A. et al. Is the insect apocalypse upon us? How to find out. Biol. Conserv. 241, 108327 (2020).

    Article  Google Scholar 

  19. Saunders, M. E., Janes, J. K. & O’Hanlon, J. C. Moving on from the insect apocalypse narrative: engaging with evidence-based insect conservation. Bioscience 70, 80–89 (2020).

    Article  Google Scholar 

  20. Thomas, C. D., Jones, T. H. & Hartley, S. E. “Insectageddon”: a call for more robust data and rigorous analyses. Glob. Change Biol. 25, 1891–1892 (2019).

    Article  Google Scholar 

  21. Outhwaite, C. L., Gregory, R. D., Chandler, R. E., Collen, B. & Isaac, N. J. B. Complex long-term biodiversity change among invertebrates, bryophytes and lichens. Nat. Ecol. Evol. 4, 384–392 (2020).

    Article  PubMed  Google Scholar 

  22. Macgregor, C. J., Williams, J. H., Bell, J. R. & Thomas, C. D. Moth biomass increases and decreases over 50 years in Britain. Nat. Ecol. Evol. 3, 1645–1649 (2019).

    Article  PubMed  Google Scholar 

  23. Gonzalez, A. et al. Estimating local biodiversity change: a critique of papers claiming no net loss of local diversity. Ecology 97, 1949–1960 (2016).

    Article  PubMed  Google Scholar 

  24. Vellend, M. et al. Estimates of local biodiversity change over time stand up to scrutiny. Ecology 98, 583–590 (2016).

    Article  Google Scholar 

  25. van Klink, R. et al. Meta-analysis reveals declines in terrestrial but increases in freshwater insect abundances. Science 368, 417–420 (2020).

    Article  CAS  PubMed  Google Scholar 

  26. Ellis, E. C. Anthropogenic transformation of the terrestrial biosphere. Phil. Trans. R. Soc. A 369, 1010–1035 (2011).

    Article  PubMed  Google Scholar 

  27. Vitousek, P. M., Mooney, H. A., Lubchenco, J. & Melillo, J. M. Human domination of Earth’s ecosystems. Science 277, 494–499 (1997).

    Article  CAS  Google Scholar 

  28. Kanakidou, M. et al. Past, present, and future atmospheric nitrogen deposition. J. Atmos. Sci. 73, 2039–2047 (2016).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  29. Dornelas, M. et al. A balance of winners and losers in the Anthropocene. Ecol. Lett. 22, 847–854 (2019).

    Article  PubMed  Google Scholar 

  30. Tylianakis, J. M., Tscharntke, T. & Lewis, O. T. Habitat modification alters the structure of tropical host–parasitoid food webs. Nature 445, 202–205 (2007).

    Article  CAS  PubMed  Google Scholar 

  31. Finke, D. L. & Snyder, W. E. Niche partitioning increases resource exploitation by diverse communities. Science 321, 1488–1490 (2008).

    Article  CAS  PubMed  Google Scholar 

  32. Crowder, D. W., Northfield, T. D., Strand, M. R. & Snyder, W. E. Organic agriculture promotes evenness and natural pest control. Nature 466, 109–112 (2010).

    Article  CAS  PubMed  Google Scholar 

  33. Mack, R. N. et al. Biotic invasions: causes, epidemiology, global consequences, and control. Ecol. Appl. 10, 689–710 (2000).

    Article  Google Scholar 

  34. Sikes, D. S. & Raithel, C. J. A review of hypotheses of decline of the endangered American burying beetle (Silphidae: Nicrophorus americanus Olivier). J. Insect Conserv. 6, 103–113 (2002).

    Article  Google Scholar 

  35. Harmon, J. P., Stephens, E. & Losey, J. The decline of native coccinellids (Coleoptera: Coccinellidae) in the United States and Canada. J. Insect Conserv. 11, 85–94 (2007).

    Article  Google Scholar 

  36. Agrawal, A. A. & Inamine, H. Mechanisms behind the monarch’s decline. Science 360, 1294–1296 (2018).

    Article  CAS  PubMed  Google Scholar 

  37. Garibaldi, L. A. et al. Wild pollinators enhance fruit set of crops regardless of honey bee abundance. Science 340, 1608–1611 (2013).

    Article  CAS  Google Scholar 

  38. Samson, F. & Knopf, F. Prairie conservation in North America. Bioscience 44, 418–421 (1994).

    Article  Google Scholar 

  39. Ratajczak, Z. et al. Abrupt change in ecological systems: inference and diagnosis. Trends Ecol. Evol. 33, 513–526 (2018).

    Article  PubMed  Google Scholar 

  40. Ives, A. R., Einarsson, Á., Jansen, V. A. A. & Gardarsson, A. High-amplitude fluctuations and alternative dynamical states of midges in Lake Myvatn. Nature 452, 84–87 (2008).

    Article  CAS  PubMed  Google Scholar 

  41. Spatiotemporal Design (NEON, National Science Foundation – National Ecological Observatory Network, 2019); https://www.neonscience.org/about/about/spatiotemporal-design

  42. North American Butterfly Count Circles (NABA, North American Butterfly Association, 2019); https://www.naba.org/butter_counts.html

  43. Burkle, L. A., Marlin, J. C. & Knight, T. M. Plant–pollinator interactions over 120 years: loss of species, co-occurrence, and function. Science 340, 1611–1615 (2013).

    Article  CAS  Google Scholar 

  44. Harvey, J. A. et al. International scientists formulate a roadmap for insect conservation and recovery. Nat. Ecol. Evol. 4, 174–176 (2020).

    Article  PubMed  Google Scholar 

  45. Cardinale, B. J. et al. Biodiversity loss and its impact on humanity. Nature 486, 59–67 (2012).

    Article  CAS  PubMed  Google Scholar 

  46. Vellend, M. et al. Global meta-analysis reveals no net change in local-scale plant biodiversity over time. Proc. Natl Acad. Sci. USA 110, 19456–19459 (2013).

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Dornelas, M. et al. Assemblage time series reveal biodiversity change but not systematic loss. Science 344, 296–299 (2014).

    Article  CAS  PubMed  Google Scholar 

  48. Newbold, T. et al. Global effects of land use on local terrestrial biodiversity. Nature 520, 45–50 (2015).

    Article  CAS  PubMed  Google Scholar 

  49. Lagos-Kutz, D. et al. The soybean aphid suction trap network: sampling the aerobiological “soup”. Am. Entomol. 66, 48–55 (2020).

    Article  Google Scholar 

  50. R Core Team R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2019).

  51. De Graaf, R. M., Tilghman, N. G. & Anderson, S. H. Foraging guilds of North American birds. Environ. Manag. 9, 493–536 (1985).

    Article  Google Scholar 

  52. Ives, A. R., Abbott, K. C. & Ziebarth, N. L. Analysis of ecological time series with ARMA(p, q) models. Ecology 91, 858–871 (2010).

    Article  PubMed  Google Scholar 

  53. Breiman, L. Random forests. Mach. Learn. 45, 5–32 (2001).

    Article  Google Scholar 

  54. Fick, S. E. & Hijmans, R. J. WorldClim 2: new 1-km spatial resolution climate surfaces for global land areas. Int. J. Climatol. 37, 4302–4315 (2017).

    Article  Google Scholar 

  55. Venter, O. et al. Global terrestrial human footprint maps for 1993 and 2009. Sci. Data 3, 160067 (2016).

    Article  PubMed  PubMed Central  Google Scholar 

  56. Halpern, B. S. et al. A global map of human impact on marine ecosystems. Science 319, 948–952 (2008).

    Article  CAS  PubMed  Google Scholar 

  57. Cutler, D. R. et al. Random forests for classification in ecology. Ecology 88, 2783–2792 (2007).

    Article  PubMed  Google Scholar 

  58. Oksanen, J. et al. vegan: Community Ecology Package. R package version 2.5-4 (2019).

  59. Jaccard, P. The distribution of the flora in the alpine zone. N. Phytol. 11, 37–50 (1912).

    Article  Google Scholar 

  60. Harrison, S., Ross, S. J. & Lawton, J. H. Beta diversity on geographic gradients in Britain. J. Anim. Ecol. 61, 151–158 (1992).

    Article  Google Scholar 

  61. Barwell, L. J., Isaac, N. J. B. & Kunin, W. E. Measuring β-diversity with species abundance data. J. Anim. Ecol. 84, 1112–1122 (2015).

    Article  PubMed  PubMed Central  Google Scholar 

  62. Koleff, P., Gaston, K. J. & Lennon, J. J. Measuring beta diversity for presence–absence data. J. Anim. Ecol. 72, 367–382 (2003).

    Article  Google Scholar 

Download references

Acknowledgements

A. R. Ives (University of Wisconsin-Madison) provided invaluable advice on our analyses, and M. R. Strand (University of Georgia) and W. F. Fagan (University of Maryland) made suggestions to improve the paper. We acknowledge funding from USDA-NIFA-OREI 2015-51300-24155 and USDA-NIFA-SCRI 2015-51181-24292 to W.E.S.

Author information

Authors and Affiliations

Authors

Contributions

M.S.C., A.R.M., W.E.S. and M.D.M. conceived of the idea for the paper, and M.S.C. and A.R.M. conducted analyses; M.S.C., A.R.M., W.E.S., M.D.M., E.M.B., D.L.-K., G.L.H., L.L.B., L.C.C., D.H.N., K.P. and S.V. assisted with data collection and curation; M.S.C., W.E.S. and M.D.M. primarily wrote the paper, although all authors contributed to the final manuscript.

Corresponding author

Correspondence to Michael S. Crossley.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Peer reviewer reports are available.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 Time trends in abundance of arthropod feeding groups among LTERs.

(a) herbivores, (b) carnivores, (c) omnivores, (d) detritivores, (e) parasites, and (f) parasitoids. Right panels depict average change in diversity metrics and 95% confidence intervals among LTERs. Blue shading and font indicate LTER sites reporting aquatic taxa.

Extended Data Fig. 2 Time trends in insectivorous bird (a) and fish (b) abundance among LTERs.

Boxplots depict medians (thick line), 25th and 75th percentiles (box edges), 95th percentiles (whiskers), and outliers (circles).

Extended Data Fig. 3 Sensitivity analysis on stringency of time series quality filtering.

Abundance trends of all taxa under (a) moderate vs. relaxed time series filtering criteria and (b) strict vs. moderate filtering criteria. (c) Boxplots of abundance trends under relaxed, moderate, and strict timer series filtering criteria. Relaxed criteria required at least four years of counts, one of which had to be non-zero (n = 5,328 out of 6,501 trends remained). Moderate criteria required at least eight years of counts, of which four had to be non-zero (n = 2,266 trends remained). Strict criteria required at least 15 years of counts, of which 10 had to be non-zero, and that temporal autocorrelation be < 1 (n = 308 trends remained).

Extended Data Fig. 4 Explanatory variables overlaid on (sorted) time trends in arthropod abundance among LTERs.

(a) Start year of LTER site sampling. (b) Human Footprint Index associated with LTER site. The average HFI value for locations within the US is 7; LTER sites ranged from 1 to 38. (c) Mean annual temperature at LTER sites. (d) Mean cumulative annual precipitation at LTER sites.

Extended Data Fig. 5 Importance of explanatory variables in predicting time trends of arthropod abundance.

Contribution of each variable to the accuracy of the Random Forests classifier, defined as the percent increase in Mean Square Error (decrease in accuracy) when the variable was excluded from decision trees.

Extended Data Fig. 6 Time trends in arthropod abundance, average among studies with similar start years.

Abundance trends are averaged among LTERs where sampling start years were earlier than 1990, spanned 1990–2000, spanned 2000–2010, or were after 2010. Results were the same when trends were grouped according to final sampling years (except that no final sampling years predated 1990).

Extended Data Fig. 7 Relationships among temporal trends in α diversity metrics.

Dots represent the change over time of a diversity metric at an LTER site. Species evenness was calculated as Pielou’s Evenness Index, and dominance represents the proportional frequency of the most abundant taxon. Light gray lines divide each plot into quadrants to help visualize sites where the sign of change in diversity metrics was similar (top right, bottom left) or opposite (top left, bottom right). Black dashes denote the line of best fit. Slopes are significant at the α = 5% level, R2 = 0.36 for evenness vs. richness, and R2 = 0.68 for evenness vs. dominance.

Extended Data Fig. 8 Time trends in Midwest Farmland aphid abundance 2006–2019.

Left panel depicts abundance trends separated by ecoregion level I. Right panel depicts abundance trends separated by ecoregion level II. Boxplots depict quantiles among LTER sites. Boxplots depict trends among insects as medians (thick line), 25th and 75th percentiles (box edges), 95th percentiles (whiskers), and outliers (circles).

Extended Data Fig. 9

Human Footprint Index values in the USA (left panel) and among LTER sites (right panel).

Extended Data Fig. 10 Relationships among temporal trends in β diversity metrics.

Dots represent the change over time of a diversity metric at an LTER site. The grey dashed line denotes the 1:1 line.

Supplementary information

Supplementary Information

Supplementary Tables 1–3.

Reporting Summary

Peer Review Information

Supplementary Table 1

Attributes of LTER sites included in analyses.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Crossley, M.S., Meier, A.R., Baldwin, E.M. et al. No net insect abundance and diversity declines across US Long Term Ecological Research sites. Nat Ecol Evol 4, 1368–1376 (2020). https://doi.org/10.1038/s41559-020-1269-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41559-020-1269-4

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing