Pest-preservation paradox among insects.

Abstract

Insects are vital to well-functioning terrestrial ecosystems. They are highly speciose and abundant across all but the very coldest areas. Only a small proportion (<1%) of recognized species are either pests or threatened species. Most species are somewhere in between and are poorly researched or remain undescribed. Among certain taxa, especially Orthoptera, Lepidoptera, Coleoptera, and Diptera, there is a paradox in that some species are pests, whereas other closely related species require conservation action. Confounding the issue is the overly simplistic and human binary perception that there are good insects that are aesthetic and benign and bad ones that are harmful to human well-being. Using Google Scholar Labs-assisted searches, we reviewed and summarized relevant literature to present a more nuanced perspective, the pest-preservation paradox (PPP), that focuses on the whole spectrum of insects and the dynamics of spatial and temporal population changes according to prevailing environmental conditions. Biologically underlying these spectrum shifts are ranges of insect genomic resilience, reproduction rates, feeding behaviors, dispersal abilities, and establishment abilities. These traits are important in human-modified, novel environments and in response to the overarching effects of climate change. Currently, certain pest species are thriving, whereas other species are becoming threatened or extinct, even among formerly abundant species. The information available today enables us to focus more specifically on the spectrum of insects and emphasize the need to study the silent majority in the spectrum center. The PPP helps move beyond the binary perception that insects are either good or bad and recognizes the nuanced spectrum between those that are pests and those that require conservation action.