Megafauna schmegafauna: A comprehensive evaluation of protections for endangered insects and arachnids across the U.S.

Reports of insect and arachnid declines have grown in recent decades. Insects and arachnids also account for most of the world’s animal biodiversity, and are ecologically and economically vital. Thus, understanding the factors influencing insect and arachnid conservation policies is urgently needed. Here we review conservation assessments for 43,035 North American insect and arachnid species and examine the factors that affect state and federal legal protections for species in the United States. We find the conservation status of 88.6% of described species in North America is unknown, and that unassessed species are unlikely to receive protection. Of insects and arachnids known to be at-risk in the U.S., 94.6% are not protected by any state or federal law, and only 2.5% are protected nationwide under the federal Endangered Species Act compared to 26.9% of at-risk U.S. bird species. Insect and arachnid protections are taxonomically biased, favoring dragonflies and damselflies (Odonata) and butterflies and moths (Lepidoptera) while overlooking other vulnerable taxa. We find that socio-economic factors are the strongest predictors of state-level conservation policies: states with economies more reliant on mining, quarrying, and oil and gas extraction are less likely to protect insects and arachnids. In states where protections exist, a greater number of species are protected when more residents hold eco-centric values. This quantitative assessment of U.S. insect and arachnid conservation highlights data deficiency, taxonomic bias, and local socio-economic variables as central impediements which have left countless species vulnerable to decline and possible extinction.