Akito Y. Kawahara,  Lawrence E. Reeves,  Jesse R. Barber, and Scott H. Black

PNAS January 12, 2021 118 (2) e2002547117

Insects constitute the vast majority of known animal species and are ubiquitous across terrestrial ecosystems, playing key ecological roles. As prey, they are critical to the survival of countless other species, including the majority of bats, birds, and freshwater fishes. As herbivores, predators, and parasites, they are major determinants of the distribution and abundance of innumerable plants and animals. The majority of flowering plants, the dominant component of most terrestrial ecosystems, depend on insects for pollination and hence reproduction. As consumers of waste products, insects are essential to the recycling of nutrients. Humans and their agriculture rely heavily on such “ecosystem services” provided by insects, which together have at least an annual value of ∼$70 billion (2020 valuation) in the United States. Insects also provide humans with honey, silk, wax, dyes, and, in many cultures, food. Insects have become essential subjects in medical and basic biological research. Furthermore, insects are one of the most easily accessible forms of wildlife, with a diversity of morphology, life history, and behavior that seems ready-made for inspiring appreciation of nature and its conservation.

We propose eight simple action items by individuals that can create insect-friendly environments and raise public awareness. Preservation and restoration of habitats that support insect diversity, as well as wildlife more broadly, is a critical element in ensuring their conservation. Any or all of our proposed actions can be adopted to slow insect declines. We encourage people to start by picking one of the eight action items discussed above, before adding others. Simple measures, such as being able to recite the 5Ps will help to educate the public about the benefits that insects provide.

See: https://www.pnas.org/content/118/2/e2002547117

Figure 1: Examples of insects that are beneficial to humans (A–J), and examples of amazing things that insects do (K–T). A, Pollinator: Honey bee (Apis mellifera). B, Bumble bee (Bombus sp.). C, Decomposer: Dung beetle (Scarabaeidae: Scarabaeinae). D, Biocontrol: Ladybird beetle (Harmonia sp.). E, Ecosystem service: Ants (Formicidae). F, Silk production: Silk moth (Bombyx mori). G, Research: Fruit fly (Drosophila melanogaster). H, Vaccine development, including coronavirus: Alfalfa looper moth (Autographa californica). I, Dye production: Cochineal scale insect (Dactylopius coccus). J, Environmental assessment: Stonefly (Plecoptera). K, Visual systems: Dragonflies (e.g., Neurothemis sp.) have near 360° vision. L, Visual defense: Hawkmoth caterpillars (Hemeroplanes triptolemus) scare predators by flipping over and resembling a snake. M, Immunity and symbiosis: Parasitic wasps (e.g., Aleiodes indiscretus) subdue their host with a virus. N, Acoustic defense: Tiger moths (Bertholdia trigona) use ultrasound to jam bat sonar. O, Biomechanics: Water striders (e.g., Gerridae) walk on water. P, Agriculture: Leaf cutter ants (Atta sp.) farm fungi. Q, Chemical defense: Bombardier beetles (Brachinus sp.) blast boiling benzoquinones at predators. R, Migration: Monarch butterflies (Danaus plexippus) migrate thousands of kilometers. S, Longevity: Periodical cicadas (e.g., Magicicada septemdecim) live for nearly two decades. T, Visual mimicry and luring: Firefly (Photinus pyralis) females mimic other firefly light flash signals to lure mate-seeking males and consume them alive. See SI Appendix for further information about each insect. Image credits: Fig. 1A: Michael J. Raupp (photographer); Fig. 1B: Flickr/James Johnstone, licensed under CC BY 2.0; Fig. 1C: L.E.R.; Fig. 1D: Flickr/John Spooner, licensed under CC BY-NC 2.0; Fig. 1E: iNaturalist/Jakob Fahr, licensed under CC BY-NC 4.0; Fig. 1F: L.E.R.; Fig. 1G: iNaturalist/alexis_orion, licensed under CC BY 4.0; Fig. 1H: iNaturalist/Anita Sprungk, licensed under CC BY-NC 4.0; Fig. 1I: Wikimedia Commons/Peggy Greb, licensed under CC BY 3.0; Fig. 1J: Flickr/USFWS Mountain-Prairie, licensed under CC BY 2.0; Fig. 1K: L.E.R.; Fig. 1L: André Victor Lucci Frietas (photographer); Fig. 1M: Wikimedia Commons/USDA; Fig. 1N: Aaron J. Corcoran (photographer); Fig. 1O: Flickr/Brad Smith, licensed under CC BY-NC 2.0; Fig. 1P: L.E.R.; Fig. 1Q: Flickr/Katja Schulz, licensed under CC BY 2.0; Fig. 1R: Jeffrey Gage (photographer); Fig. 1S: Michael J. Raupp (photographer); and Fig. 1T: Flickr/James Jordan, licensed under CC BY-ND 2.0.