Insects of Craters of the Moon National Monument, Idaho

Horning, D

This study consisted of an inventory of the insectspecies inhabitating Craters of the Moon National Monument,Idaho, with special attention given to the associations of insects and plants and the relating of insects with particular lava and non-lava habitats. The period of study included the summers of 1964 and 1965, with the majority of field workconducted in 1965. The largest number of insect species was collected from a non-volcanic area, Lava habitats varied in number of insect species. Old, decomposed cinder cones supported the greatest number of insect species. The decomposed aa and pahoehoe lava flows were less favorable to insect activity than the cinder cones. Undecomposed pahoehoe lava flows and bare cinder areas did not have an abundance of plant life, and the insect populations were markedly lower. The least favorable habitat to insects in the Monument was the undecomposed aa lava flows, Several plant species growing on lava were found to be particularly attractive to insects. These include Chamaebatiaria millefolium (Torrey) Maximowicz, Chrysothamnus nauseosus (Pallas) Britton, Phacelia leucophylla Torrey, andPinus flexilis James. Only a few plant species were considered to be of little significance to insect life. During this study, 20 orders, 225 families, 1054 genera and 1844 species and subspecies were found from Craters of the Moon National Monument. More than 30 of the species are new to science. Also included in the list of species are many new state records and several new United States records, The order Hymenoptera was best represented with 315 genera, 676 species, and 4054 collected specimens. Diptera ranked next in number with 243 genera, 425 species, and 1566 collected specimens, Coleoptera was third in number with 201 genera, 325 species, and 2192 collected specimens.