Threatened, endangered, and sensitive insects in eastern Oregon and Washington forests and adjacent lands

Insects play an integral role in the health of forest ecosystems. While most insect species in eastern Oregon and Washington forests are presumed to be abundant and secure, some may be rare or in decline. Accounts are given for fifteen east-side forest insect species currently listed as threatened, endangered, or sensitive (TES). We discuss reasons for their listing, which include peripheral populations, relict species, species with restricted habitats or hosts, and endemic species. Whether the needs of currently listed TES east-side forest insects are being met by current management practices can only be ascertained if adequate information is available on their distribution, abundance, habitat requirements, and biologies. However, this information is lacking for many species. For instance, five of the TES species discussed in this paper have poorly known distributions, and better information may change their status. Application of general principles for the conservation of invertebrate diversity and functions may help prevent other east-side forest insects from acquiring federal or state TES classification and could aid species already listed. Many practices already undertaken by federal land managers may be helping to protect TES populations and habitat. Specific management practices, such as preservation of key habitats at risk of degradation or alteration (e.g., springs and sphagnum bogs), may be necessary to prevent the decline or local extinction of some TES insects. Given the inadequate information available for most non-pest forest insects and their great diversity, a more systematic approach to their conservation and management may be needed.