Arthropods and Multispecies Habitat Conservation Plans: Are We Missing Something?

Arthropods constitute well over one-half of the species of higher life on the planet and are the dominant terrestrial life form on the planet. Unfortunately, very little is known about most arthropod species. There are an estimated 163,487 species of insects in North America, of which only 66% are taxonomically known. Similarly, there are an estimated 35,514 species of North American arachnids, of which only 9316 are described; over 73% have yet to be discovered and described. Without the basic taxonomic and life history knowledge for most of the terrestrial species (i.e., arthropods) of North American ecosystems, land managers are faced with the challenge of developing, selecting, and managing biotic reserves and habitat conservation plans for which they know very little about the majority of organisms found within such reserves or covered by such plans. With respect to arthropods, this challenge includes taking into account poorly described species being used as political tools to stop development (as opposed to actually protecting a truly endangered species), thus confounding the habitat conservation planning process and ensuring that "surprises" in the form of new listings will occur within any multispecies habitat plan. Finally, using various scenarios and assumptions, estimates of the true number of endangered insects and arachnids are provided to illustrate the fact that the suspected number of threatened, endangered, and extinct species is probably low by at least an order of magnitude.