Insect Declines in the Anthropocene.

By D. Wagner. Annual Review of Entomology, 2020

1,125 citations recorded by the source corpus.

Insect declines are being reported worldwide for flying, ground, and aquatic lineages. Most reports come from western and northern Europe, where the insect fauna is well-studied and there are considerable demographic data for many taxonomically disparate lineages. Additional cases of faunal losses have been noted from Asia, North America, the Arctic, the Neotropics, and elsewhere. While this review addresses both species loss and population declines, its emphasis is on the latter. Declines of abundant species can be especially worrisome, given that they anchor trophic interactions and shoulder many of essential ecosystem services of their respective communities. A review of the factors believed to be responsible for observed collapses and those perceived to be especially threatening to insects form the core of this treatment. In addition to widely recognized threats to insect biodiversity, e.g., habitat destruction, agricultural intensification (including pesticide use), climate change, and invasive species, this assessment highlights a few less commonly considered factors such as atmospheric nitrification from the burning of fossil fuels and the effects of droughts and changing precipitation patterns. Because the geographic extent and magnitude of insect declines are largely unknown, there is an urgent need for monitoring efforts, especially across ecological gradients, which will help to identify important causal factors in declines. This review also considers the status of vertebrate insectivores, reporting bias, challenges inherent in collecting and interpreting insect demographic data, and cases of increasing insect abundance. Expected final online publication date for the Annual Review of Entomology, Volume 65 is January 7, 2020. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Subfields: Ecological Modeling, Ecology, Evolution, Behavior and Systematics, Global and Planetary Change

View Paper: https://www.semanticscholar.org/paper/79c8306c4791f2b094e6629483f75eb9f4444af8

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Citations in the corpus

Vertebrates on the brink as indicators of biological annihilation and the sixth mass extinction (2020, neutral): “About 75% of all flying insects in national parks in Germany disappeared in 25 y (16), and there are numerous signs that many species of insects are heading for the exit (34, 35).”
Declines in insect abundance and diversity: We know enough to act now (2019, background): “The complexities of climate change are coming into focus, especially as they involve not only shifting mean conditions but also increasing extremes (Wagner, 2020).”
Insect responses to global change offer signposts for biodiversity and conservation (2020, background): “Global and continental assessments for insects and other invertebrates, necessarily biased towards Europe and North America, show overall declines in abundance of terrestrial species (Dirzo et al., 2014; Pilotto et al., 2020).”
Interpreting insect declines: seven challenges and a way forward (2020, background): “Populations of many insect species are declining (Wagner, 2020).”
Simplistic understandings of farmer motivations could undermine the environmental potential of the common agricultural policy (2020, background): “There is emerging evidence that 111 insect biomass and abundance have declined rapidly in European agricultural land in the last 112 few decades (Wagner, 2020).”
A Global Perspective on Firefly Extinction Threats (2020, background): “…apparent that such opinions cannot be used to identify the relative importance or extent of such threats, our results are consistent with other assessments of the multifaceted causes for general declines in insect abundance and biodiversity (e.g., Leather 2018, Wagner 2018, 2020, Homburg et al.”
Scientists’ warning to humanity on the freshwater biodiversity crisis (2020, background): “Since 2000, abundances of freshwater insect (Sán- chez-Bayo and Wyckhuys 2019; Wagner 2019) and fish populations organisms have become dramatically reduced, at local scales in both temperate (Freyhof and Brooks 2017) and tropical (Cohen et al. 2016a; Pelicice et al. 2017) latitudes, and in…”
Are declines in insects and insectivorous birds related? (2021, background): “Montgomery, G. A., R. R. Dunn, R. Fox, E. Jongejans, S. R. Leather, M. E. Saunders, C. R. Shortall, M. W. Tingley, and D. L. Wagner (2020).”
Cascading extinctions as a hidden driver of insect decline (2020, background): “…(Habel et al., 2019; Sánchez-Bayo & Wyckhuys, 2019; Cardoso et al., 2020; Fiza Fatima et al., 2020; Montgomery et al., 2020; van Klink et al., 2020; Wagner, 2020): (I) habitat loss and fragmentation associated with housing development and agriculture, timber, and livestock production, (II)…”
Thermal Plasticity in Insects’ Response to Climate Change and to Multifactorial Environments (2020, background): “It is also a group with recent worrying trends: steep global population declines (Sánchez-Bayo and Wyckhuys, 2019; Didham et al., 2020; Wagner, 2020), as well as expansions of agricultural pests and disease vectors (Song et al., 2017; Ryan et al., 2019).”